From 0d8717cc83f0547e67770cc3a321347ac9be9cdf Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 17:08:55 +0200
Subject: [PATCH 01/45] Make version available in config.

---
 cmd/telegraf/telegraf.go |  2 +-
 config/config.go         | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/cmd/telegraf/telegraf.go b/cmd/telegraf/telegraf.go
index 688c1e5bdd6c5..d7d5e444f36b1 100644
--- a/cmd/telegraf/telegraf.go
+++ b/cmd/telegraf/telegraf.go
@@ -194,7 +194,7 @@ func runAgent(ctx context.Context,
 	log.Printf("I! Starting Telegraf %s", version)
 
 	// If no other options are specified, load the config file and run.
-	c := config.NewConfig()
+	c := config.NewConfig(version)
 	c.OutputFilters = outputFilters
 	c.InputFilters = inputFilters
 	var err error
diff --git a/config/config.go b/config/config.go
index 97f9c35b3ab55..231d12d7a4b7c 100644
--- a/config/config.go
+++ b/config/config.go
@@ -77,12 +77,17 @@ type Config struct {
 	// Processors have a slice wrapper type because they need to be sorted
 	Processors    models.RunningProcessors
 	AggProcessors models.RunningProcessors
+
+	versionMajor int
+	versionMinor int
 }
 
 // NewConfig creates a new struct to hold the Telegraf config.
 // For historical reasons, It holds the actual instances of the running plugins
 // once the configuration is parsed.
-func NewConfig() *Config {
+func NewConfig(version string) *Config {
+	maj, min := parseVersion(version)
+
 	c := &Config{
 		UnusedFields: map[string]bool{},
 
@@ -102,6 +107,9 @@ func NewConfig() *Config {
 		AggProcessors: make([]*models.RunningProcessor, 0),
 		InputFilters:  make([]string, 0),
 		OutputFilters: make([]string, 0),
+
+		versionMajor: maj,
+		versionMinor: min,
 	}
 
 	tomlCfg := &toml.Config{
@@ -200,6 +208,9 @@ type AgentConfig struct {
 
 	Hostname     string
 	OmitHostname bool
+
+	versionMajor int
+	versionMinor int
 }
 
 // InputNames returns a list of strings of the configured inputs.

From 8c52ceed27afb4b0415c0b7b2ddd8babe290cf1b Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 17:09:53 +0200
Subject: [PATCH 02/45] Define interface for declaring a plugin as deprecated.

---
 plugin.go | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/plugin.go b/plugin.go
index f9dcaeac0344c..322f721fd66a3 100644
--- a/plugin.go
+++ b/plugin.go
@@ -23,6 +23,13 @@ type PluginDescriber interface {
 	Description() string
 }
 
+// PluginDeprecator marks a plugin as deprecated and provides hints to the user.
+type PluginDeprecator interface {
+	// DeprecationNotice returns the version since when the plugin is deprecated and
+	// (optionally) provides a deprecation notice allowing to suggest replacements etc.
+	DeprecationNotice() (since string, notice string)
+}
+
 // Logger defines an plugin-related interface for logging.
 type Logger interface {
 	// Errorf logs an error message, patterned after log.Printf.

From abae0812fb5273f6502bb41dae8ecce5da90a983 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 17:15:09 +0200
Subject: [PATCH 03/45] Define telegraf version for the non-tagged case.

---
 Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Makefile b/Makefile
index 290008d8c34b0..2b5864602564a 100644
--- a/Makefile
+++ b/Makefile
@@ -44,6 +44,8 @@ HOSTGO := env -u GOOS -u GOARCH -u GOARM -- go
 LDFLAGS := $(LDFLAGS) -X main.commit=$(commit) -X main.branch=$(branch) -X main.goos=$(GOOS) -X main.goarch=$(GOARCH)
 ifneq ($(tag),)
 	LDFLAGS += -X main.version=$(version)
+else
+	LDFLAGS += -X main.version=$(version)-$(commit)
 endif
 
 # Go built-in race detector works only for 64 bits architectures.

From aa4790ebfd4487563f079a00bda75bd699c5a32a Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 17:15:31 +0200
Subject: [PATCH 04/45] Implement deprecation handling.

---
 config/deprecation.go | 153 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 153 insertions(+)
 create mode 100644 config/deprecation.go

diff --git a/config/deprecation.go b/config/deprecation.go
new file mode 100644
index 0000000000000..24e719b1ab858
--- /dev/null
+++ b/config/deprecation.go
@@ -0,0 +1,153 @@
+package config
+
+import (
+	"fmt"
+	"log"
+	"reflect"
+	"strconv"
+	"strings"
+
+	"github.com/influxdata/telegraf"
+)
+
+type Escalation int
+
+const (
+	None Escalation = iota
+	Warn
+	Error
+)
+
+const (
+	pluginWarnNotice = "Deprecated plugin will be removed soon, please switch to a supported plugin!"
+	optionWarnNotice = "Deprecated options will be removed with the next major version, please adapt your config!"
+)
+
+func (c *Config) handleDeprecation(name string, plugin interface{}) error {
+	// First check if the whole plugin is deprecated
+	if deprecatedPlugin, ok := plugin.(telegraf.PluginDeprecator); ok {
+		since, notice := deprecatedPlugin.DeprecationNotice()
+		switch c.getDeprecationEscalation(since) {
+		case Warn:
+			printPluginDeprecationNotice("W! [agent] DeprecationWarning", name, since, notice)
+			// We will not check for any deprecated options as the whole plugin is deprecated anyway.
+			return nil
+		case Error:
+			printPluginDeprecationNotice("E! [agent] DeprecationError", name, since, notice)
+			// We are past the grace period
+			return fmt.Errorf("plugin deprecated")
+		}
+	}
+
+	// Check for deprecated options
+	deprecatedOptions := make([]string, 0)
+	walkPluginStruct(reflect.ValueOf(plugin), func(field reflect.StructField, value reflect.Value) {
+		tags := strings.SplitN(field.Tag.Get("deprecated"), ";", 2)
+		if len(tags) < 1 || tags[0] == "" {
+			return
+		}
+		since := tags[0]
+		notice := ""
+		if len(tags) > 1 {
+			notice = tags[1]
+		}
+
+		// Get the toml field name
+		option := field.Tag.Get("toml")
+		if option == "" {
+			option = field.Name
+		}
+
+		switch c.getDeprecationEscalation(since) {
+		case Warn:
+			printOptionDeprecationNotice("W! [agent] DeprecationWarning", name, option, since, notice)
+		case Error:
+			printOptionDeprecationNotice("E! [agent] DeprecationError", name, option, since, notice)
+			deprecatedOptions = append(deprecatedOptions, option)
+		}
+	})
+
+	if len(deprecatedOptions) > 0 {
+		return fmt.Errorf("plugin options %q deprecated", strings.Join(deprecatedOptions, ","))
+	}
+
+	return nil
+}
+
+func (c *Config) getDeprecationEscalation(since string) Escalation {
+	sinceMajor, sinceMinor := parseVersion(since)
+	if c.versionMajor > sinceMajor {
+		return Error
+	}
+	if c.versionMajor == sinceMajor && c.versionMinor >= sinceMinor {
+		return Warn
+	}
+
+	return None
+}
+
+func printPluginDeprecationNotice(prefix, name, since, notice string) {
+	if notice != "" {
+		log.Printf("%s: Plugin %q deprecated since version %s: %s", prefix, name, since, notice)
+	} else {
+		log.Printf("%s: Plugin %q deprecated since version %s", prefix, name, since)
+	}
+	log.Printf("Please note: %s", pluginWarnNotice)
+}
+
+func printOptionDeprecationNotice(prefix, name, option, since, notice string) {
+	if notice != "" {
+		log.Printf("%s: Option %q of plugin %q deprecated since version %s: %s", prefix, option, name, since, notice)
+	} else {
+		log.Printf("%s: Option %q of plugin %q deprecated since version %s", prefix, option, name, since)
+	}
+	log.Printf("Please note: %s", optionWarnNotice)
+}
+
+func walkPluginStruct(value reflect.Value, fn func(f reflect.StructField, fv reflect.Value)) {
+	v := reflect.Indirect(value)
+	t := v.Type()
+
+	for i := 0; i < t.NumField(); i++ {
+		field := t.Field(i)
+		fieldValue := v.Field(i)
+
+		if field.PkgPath != "" {
+			continue
+		}
+		switch field.Type.Kind() {
+		case reflect.Struct:
+			walkPluginStruct(fieldValue, fn)
+
+		case reflect.Array, reflect.Slice:
+			for j := 0; j < fieldValue.Len(); j++ {
+				fn(field, fieldValue.Index(j))
+			}
+		case reflect.Map:
+			iter := fieldValue.MapRange()
+			for iter.Next() {
+				fn(field, iter.Value())
+			}
+		default:
+			fn(field, fieldValue)
+		}
+	}
+}
+
+func parseVersion(version string) (major, minor int) {
+	parts := strings.SplitN(version, ".", 3)
+	if len(parts) < 2 {
+		panic(fmt.Errorf("insufficient version fields in %q", version))
+	}
+
+	major, err := strconv.Atoi(parts[0])
+	if err != nil {
+		panic(fmt.Errorf("invalid version major in %q", version))
+	}
+
+	minor, err = strconv.Atoi(parts[1])
+	if err != nil {
+		panic(fmt.Errorf("invalid version major in %q", version))
+	}
+	return major, minor
+}

From f776ddf5c9024e8fd52de1e2ba2229dd2ec75cbe Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 17:22:33 +0200
Subject: [PATCH 05/45] Handle deprecation.

---
 config/config.go | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/config/config.go b/config/config.go
index 231d12d7a4b7c..5674c7e608016 100644
--- a/config/config.go
+++ b/config/config.go
@@ -1033,6 +1033,10 @@ func (c *Config) addAggregator(name string, table *ast.Table) error {
 		return err
 	}
 
+	if err := c.handleDeprecation("aggregators."+name, aggregator); err != nil {
+		return err
+	}
+
 	c.Aggregators = append(c.Aggregators, models.NewRunningAggregator(aggregator, conf))
 	return nil
 }
@@ -1081,6 +1085,10 @@ func (c *Config) newRunningProcessor(
 		}
 	}
 
+	if err := c.handleDeprecation("processors."+processorConfig.Name, processor); err != nil {
+		return nil, err
+	}
+
 	rf := models.NewRunningProcessor(processor, processorConfig)
 	return rf, nil
 }
@@ -1115,6 +1123,10 @@ func (c *Config) addOutput(name string, table *ast.Table) error {
 		return err
 	}
 
+	if err := c.handleDeprecation("outputs."+name, output); err != nil {
+		return err
+	}
+
 	ro := models.NewRunningOutput(output, outputConfig, c.Agent.MetricBatchSize, c.Agent.MetricBufferLimit)
 	c.Outputs = append(c.Outputs, ro)
 	return nil
@@ -1164,6 +1176,10 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 		return err
 	}
 
+	if err := c.handleDeprecation("inputs."+name, input); err != nil {
+		return err
+	}
+
 	rp := models.NewRunningInput(input, pluginConfig)
 	rp.SetDefaultTags(c.Tags)
 	c.Inputs = append(c.Inputs, rp)

From 7c6e65462788a3116dfc0bf602f429d1d679bc7f Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 17:23:11 +0200
Subject: [PATCH 06/45] Deprecate httpjson as a showcase.

---
 plugins/inputs/httpjson/httpjson.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/plugins/inputs/httpjson/httpjson.go b/plugins/inputs/httpjson/httpjson.go
index 10a4cb0c17643..12a70a3b3e0c3 100644
--- a/plugins/inputs/httpjson/httpjson.go
+++ b/plugins/inputs/httpjson/httpjson.go
@@ -283,6 +283,10 @@ func (h *HTTPJSON) sendRequest(serverURL string) (string, float64, error) {
 	return string(body), responseTime, err
 }
 
+func (h *HTTPJSON) DeprecationNotice() (since, notice string) {
+	return "1.6", "use 'inputs.http' instead"
+}
+
 func init() {
 	inputs.Add("httpjson", func() telegraf.Input {
 		return &HTTPJSON{

From 09cbfa3049c952171ad7b64686a9d7fd20884d8b Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 17:23:58 +0200
Subject: [PATCH 07/45] Deprecate 'address' option of http_response as
 showcase.

---
 plugins/inputs/http_response/http_response.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins/inputs/http_response/http_response.go b/plugins/inputs/http_response/http_response.go
index 799f664d1e7b0..ef5a1f4e85069 100644
--- a/plugins/inputs/http_response/http_response.go
+++ b/plugins/inputs/http_response/http_response.go
@@ -28,7 +28,7 @@ const (
 
 // HTTPResponse struct
 type HTTPResponse struct {
-	Address         string   // deprecated in 1.12
+	Address         string   `toml:"address" deprecated:"1.12;use 'urls' instead"`
 	URLs            []string `toml:"urls"`
 	HTTPProxy       string   `toml:"http_proxy"`
 	Body            string

From 8d23064eb214dc66e8506b0a2c892e02bdd412a2 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 17:39:24 +0200
Subject: [PATCH 08/45] Color deprecation output to increase visibility.

---
 config/deprecation.go | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index 24e719b1ab858..4de70f99b959a 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -7,6 +7,8 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/fatih/color"
+
 	"github.com/influxdata/telegraf"
 )
 
@@ -29,11 +31,13 @@ func (c *Config) handleDeprecation(name string, plugin interface{}) error {
 		since, notice := deprecatedPlugin.DeprecationNotice()
 		switch c.getDeprecationEscalation(since) {
 		case Warn:
-			printPluginDeprecationNotice("W! [agent] DeprecationWarning", name, since, notice)
+			prefix := "W! " + color.YellowString("DeprecationWarning")
+			printPluginDeprecationNotice(prefix, name, since, notice)
 			// We will not check for any deprecated options as the whole plugin is deprecated anyway.
 			return nil
 		case Error:
-			printPluginDeprecationNotice("E! [agent] DeprecationError", name, since, notice)
+			prefix := "E! " + color.RedString("DeprecationError")
+			printPluginDeprecationNotice(prefix, name, since, notice)
 			// We are past the grace period
 			return fmt.Errorf("plugin deprecated")
 		}
@@ -60,9 +64,11 @@ func (c *Config) handleDeprecation(name string, plugin interface{}) error {
 
 		switch c.getDeprecationEscalation(since) {
 		case Warn:
-			printOptionDeprecationNotice("W! [agent] DeprecationWarning", name, option, since, notice)
+			prefix := "W! " + color.YellowString("DeprecationWarning")
+			printOptionDeprecationNotice(prefix, name, option, since, notice)
 		case Error:
-			printOptionDeprecationNotice("E! [agent] DeprecationError", name, option, since, notice)
+			prefix := "E! " + color.RedString("DeprecationError")
+			printOptionDeprecationNotice(prefix, name, option, since, notice)
 			deprecatedOptions = append(deprecatedOptions, option)
 		}
 	})

From ceb67fd25952da197a5e7e8799e8ae4948594a7b Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 18:05:25 +0200
Subject: [PATCH 09/45] Report only those deprecated fields that contain data.

---
 config/deprecation.go | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index 4de70f99b959a..36f5c4542ef9b 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -46,6 +46,11 @@ func (c *Config) handleDeprecation(name string, plugin interface{}) error {
 	// Check for deprecated options
 	deprecatedOptions := make([]string, 0)
 	walkPluginStruct(reflect.ValueOf(plugin), func(field reflect.StructField, value reflect.Value) {
+		// Try to report only those fields that are set
+		if value.IsZero() {
+			return
+		}
+
 		tags := strings.SplitN(field.Tag.Get("deprecated"), ";", 2)
 		if len(tags) < 1 || tags[0] == "" {
 			return
@@ -134,9 +139,8 @@ func walkPluginStruct(value reflect.Value, fn func(f reflect.StructField, fv ref
 			for iter.Next() {
 				fn(field, iter.Value())
 			}
-		default:
-			fn(field, fieldValue)
 		}
+		fn(field, fieldValue)
 	}
 }
 

From 19c9cd8680285af3daaf296ba361c719e7de0df3 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 18:05:47 +0200
Subject: [PATCH 10/45] Flag known deprecated packages.

---
 plugins/inputs/cassandra/cassandra.go                         | 4 ++++
 plugins/inputs/http_listener_v2/http_listener_v2.go           | 4 ++++
 plugins/inputs/httpjson/httpjson.go                           | 2 +-
 plugins/inputs/jolokia/jolokia.go                             | 4 ++++
 plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go | 4 ++++
 plugins/inputs/logparser/logparser.go                         | 4 ++++
 plugins/inputs/snmp_legacy/snmp_legacy.go                     | 4 ++++
 plugins/inputs/tcp_listener/tcp_listener.go                   | 4 ++++
 plugins/inputs/udp_listener/udp_listener.go                   | 4 ++++
 plugins/outputs/riemann_legacy/riemann.go                     | 4 ++++
 10 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/plugins/inputs/cassandra/cassandra.go b/plugins/inputs/cassandra/cassandra.go
index d1c23caadc68a..96b6d9bf46ed7 100644
--- a/plugins/inputs/cassandra/cassandra.go
+++ b/plugins/inputs/cassandra/cassandra.go
@@ -313,6 +313,10 @@ func (c *Cassandra) Gather(acc telegraf.Accumulator) error {
 	return nil
 }
 
+func (_ *Cassandra) DeprecationNotice() (since, notice string) {
+	return "1.7", "use 'inputs.jolokia2' with the 'cassandra.conf' example configuration instead"
+}
+
 func init() {
 	inputs.Add("cassandra", func() telegraf.Input {
 		return &Cassandra{jClient: &JolokiaClientImpl{client: &http.Client{}}}
diff --git a/plugins/inputs/http_listener_v2/http_listener_v2.go b/plugins/inputs/http_listener_v2/http_listener_v2.go
index d2a2e5f35214e..f62d59e929cff 100644
--- a/plugins/inputs/http_listener_v2/http_listener_v2.go
+++ b/plugins/inputs/http_listener_v2/http_listener_v2.go
@@ -385,6 +385,10 @@ func (h *HTTPListenerV2) authenticateIfSet(handler http.HandlerFunc, res http.Re
 	}
 }
 
+func (_ *HTTPListenerV2) DeprecationNotice() (since, notice string) {
+	return "1.9", "has been renamed to 'influxdb_listener', use 'inputs.influxdb_listener' or 'inputs.influxdb_listener_v2' instead"
+}
+
 func init() {
 	inputs.Add("http_listener_v2", func() telegraf.Input {
 		return &HTTPListenerV2{
diff --git a/plugins/inputs/httpjson/httpjson.go b/plugins/inputs/httpjson/httpjson.go
index 12a70a3b3e0c3..77d3636138616 100644
--- a/plugins/inputs/httpjson/httpjson.go
+++ b/plugins/inputs/httpjson/httpjson.go
@@ -283,7 +283,7 @@ func (h *HTTPJSON) sendRequest(serverURL string) (string, float64, error) {
 	return string(body), responseTime, err
 }
 
-func (h *HTTPJSON) DeprecationNotice() (since, notice string) {
+func (_ *HTTPJSON) DeprecationNotice() (since, notice string) {
 	return "1.6", "use 'inputs.http' instead"
 }
 
diff --git a/plugins/inputs/jolokia/jolokia.go b/plugins/inputs/jolokia/jolokia.go
index af5e3de283800..cb39ca25764ed 100644
--- a/plugins/inputs/jolokia/jolokia.go
+++ b/plugins/inputs/jolokia/jolokia.go
@@ -318,6 +318,10 @@ func (j *Jolokia) Gather(acc telegraf.Accumulator) error {
 	return nil
 }
 
+func (_ *Jolokia) DeprecationNotice() (since, notice string) {
+	return "1.5", "use 'inputs.jolokia2' instead"
+}
+
 func init() {
 	inputs.Add("jolokia", func() telegraf.Input {
 		return &Jolokia{
diff --git a/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go b/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go
index ab19e0875820a..3803808d9cd1c 100644
--- a/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go
+++ b/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go
@@ -184,6 +184,10 @@ func (k *Kafka) Gather(_ telegraf.Accumulator) error {
 	return nil
 }
 
+func (_ *Kafka) DeprecationNotice() (since, notice string) {
+	return "1.20", "use 'inputs.kafka_consumer' instead, NOTE: 'kafka_consumer' only supports Kafka v0.8+"
+}
+
 func init() {
 	inputs.Add("kafka_consumer_legacy", func() telegraf.Input {
 		return &Kafka{}
diff --git a/plugins/inputs/logparser/logparser.go b/plugins/inputs/logparser/logparser.go
index 83f5abd210bdd..017ee6868a968 100644
--- a/plugins/inputs/logparser/logparser.go
+++ b/plugins/inputs/logparser/logparser.go
@@ -360,6 +360,10 @@ func (l *LogParserPlugin) Stop() {
 	offsetsMutex.Unlock()
 }
 
+func (_ *LogParserPlugin) DeprecationNotice() (since, notice string) {
+	return "1.15", "use 'inputs.tail' with 'grok' data format instead"
+}
+
 func init() {
 	inputs.Add("logparser", func() telegraf.Input {
 		return NewLogParser()
diff --git a/plugins/inputs/snmp_legacy/snmp_legacy.go b/plugins/inputs/snmp_legacy/snmp_legacy.go
index ce454cbfbad36..ddbb4d276c1dd 100644
--- a/plugins/inputs/snmp_legacy/snmp_legacy.go
+++ b/plugins/inputs/snmp_legacy/snmp_legacy.go
@@ -815,6 +815,10 @@ func (h *Host) HandleResponse(
 	return lastOid, nil
 }
 
+func (_ *Snmp) DeprecationNotice() (since, notice string) {
+	return "1.20", "use 'inputs.snmp' instead"
+}
+
 func init() {
 	inputs.Add("snmp_legacy", func() telegraf.Input {
 		return &Snmp{}
diff --git a/plugins/inputs/tcp_listener/tcp_listener.go b/plugins/inputs/tcp_listener/tcp_listener.go
index 8eeaa9cff8091..f591149a7c556 100644
--- a/plugins/inputs/tcp_listener/tcp_listener.go
+++ b/plugins/inputs/tcp_listener/tcp_listener.go
@@ -297,6 +297,10 @@ func (t *TCPListener) remember(id string, conn *net.TCPConn) {
 	t.conns[id] = conn
 }
 
+func (_ *TCPListener) DeprecationNotice() (since, notice string) {
+	return "1.3", "use 'inputs.socket_listener' instead"
+}
+
 func init() {
 	inputs.Add("tcp_listener", func() telegraf.Input {
 		return &TCPListener{
diff --git a/plugins/inputs/udp_listener/udp_listener.go b/plugins/inputs/udp_listener/udp_listener.go
index 39fef79ce1b98..8184b114062d2 100644
--- a/plugins/inputs/udp_listener/udp_listener.go
+++ b/plugins/inputs/udp_listener/udp_listener.go
@@ -221,6 +221,10 @@ func (u *UDPListener) udpParser() {
 	}
 }
 
+func (_ *UDPListener) DeprecationNotice() (since, notice string) {
+	return "1.3", "use 'inputs.socket_listener' instead"
+}
+
 func init() {
 	inputs.Add("udp_listener", func() telegraf.Input {
 		return &UDPListener{
diff --git a/plugins/outputs/riemann_legacy/riemann.go b/plugins/outputs/riemann_legacy/riemann.go
index 0bd0f6b876c68..e071928a931c9 100644
--- a/plugins/outputs/riemann_legacy/riemann.go
+++ b/plugins/outputs/riemann_legacy/riemann.go
@@ -147,6 +147,10 @@ func serviceName(s string, n string, t map[string]string, f string) string {
 	return strings.Join(serviceStrings, s)
 }
 
+func (_ *Riemann) DeprecationNotice() (since, notice string) {
+	return "1.20", "use 'outputs.riemann' instead (see https://github.com/influxdata/telegraf/issues/1878)"
+}
+
 func init() {
 	outputs.Add("riemann_legacy", func() telegraf.Output {
 		return &Riemann{}

From c0678acd89c401bba91eccb072c0111df08b3590 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 19:42:02 +0200
Subject: [PATCH 11/45] Refactor deprecation handling a bit and implement
 deprecation listing.

---
 config/config.go      |   8 +-
 config/deprecation.go | 184 +++++++++++++++++++++++++++++++++++-------
 2 files changed, 157 insertions(+), 35 deletions(-)

diff --git a/config/config.go b/config/config.go
index 5674c7e608016..5f8f7c59f34f2 100644
--- a/config/config.go
+++ b/config/config.go
@@ -1033,7 +1033,7 @@ func (c *Config) addAggregator(name string, table *ast.Table) error {
 		return err
 	}
 
-	if err := c.handleDeprecation("aggregators."+name, aggregator); err != nil {
+	if err := c.printUserDeprecation("aggregators."+name, aggregator); err != nil {
 		return err
 	}
 
@@ -1085,7 +1085,7 @@ func (c *Config) newRunningProcessor(
 		}
 	}
 
-	if err := c.handleDeprecation("processors."+processorConfig.Name, processor); err != nil {
+	if err := c.printUserDeprecation("processors."+processorConfig.Name, processor); err != nil {
 		return nil, err
 	}
 
@@ -1123,7 +1123,7 @@ func (c *Config) addOutput(name string, table *ast.Table) error {
 		return err
 	}
 
-	if err := c.handleDeprecation("outputs."+name, output); err != nil {
+	if err := c.printUserDeprecation("outputs."+name, output); err != nil {
 		return err
 	}
 
@@ -1176,7 +1176,7 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 		return err
 	}
 
-	if err := c.handleDeprecation("inputs."+name, input); err != nil {
+	if err := c.printUserDeprecation("inputs."+name, input); err != nil {
 		return err
 	}
 
diff --git a/config/deprecation.go b/config/deprecation.go
index 36f5c4542ef9b..18341b0222891 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -4,50 +4,80 @@ import (
 	"fmt"
 	"log"
 	"reflect"
+	"sort"
 	"strconv"
 	"strings"
 
 	"github.com/fatih/color"
 
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/aggregators"
+	"github.com/influxdata/telegraf/plugins/inputs"
+	"github.com/influxdata/telegraf/plugins/outputs"
+	"github.com/influxdata/telegraf/plugins/processors"
 )
 
+const (
+	pluginWarnNotice = "Deprecated plugin will be removed soon, please switch to a supported plugin!"
+	optionWarnNotice = "Deprecated options will be removed with the next major version, please adapt your config!"
+)
+
+// Escalation level for the plugin or option
 type Escalation int
 
+func (e Escalation) String() string {
+	switch e {
+	case Warn:
+		return "WARN"
+	case Error:
+		return "ERROR"
+	}
+	return "NONE"
+}
+
 const (
+	// None means no deprecation
 	None Escalation = iota
+	// Warn means deprecated but still within the grace period
 	Warn
+	// Error means deprecated and beyond grace period
 	Error
 )
 
-const (
-	pluginWarnNotice = "Deprecated plugin will be removed soon, please switch to a supported plugin!"
-	optionWarnNotice = "Deprecated options will be removed with the next major version, please adapt your config!"
-)
+// DeprecationInfo contains all important information to describe a deprecated entity
+type DeprecationInfo struct {
+	// Name of the plugin or plugin option
+	Name string
+	// Level of deprecation
+	Level Escalation
+	// Since which version the plugin or plugin option is deprecated
+	Since string
+	// Notice to the user about alternatives or further information
+	Notice string
+}
+
+// PluginDeprecationInfo holds all information about a deprecated plugin or it's options
+type PluginDeprecationInfo struct {
+	DeprecationInfo
+
+	// Options deprecated for this plugin
+	Options []DeprecationInfo
+}
+
+func (c *Config) collectDeprecationInfo(name string, plugin interface{}, all bool) PluginDeprecationInfo {
+	info := PluginDeprecationInfo{}
+	info.Name = name
 
-func (c *Config) handleDeprecation(name string, plugin interface{}) error {
 	// First check if the whole plugin is deprecated
 	if deprecatedPlugin, ok := plugin.(telegraf.PluginDeprecator); ok {
-		since, notice := deprecatedPlugin.DeprecationNotice()
-		switch c.getDeprecationEscalation(since) {
-		case Warn:
-			prefix := "W! " + color.YellowString("DeprecationWarning")
-			printPluginDeprecationNotice(prefix, name, since, notice)
-			// We will not check for any deprecated options as the whole plugin is deprecated anyway.
-			return nil
-		case Error:
-			prefix := "E! " + color.RedString("DeprecationError")
-			printPluginDeprecationNotice(prefix, name, since, notice)
-			// We are past the grace period
-			return fmt.Errorf("plugin deprecated")
-		}
+		info.Since, info.Notice = deprecatedPlugin.DeprecationNotice()
+		info.Level = c.getDeprecationEscalation(info.Since)
 	}
 
 	// Check for deprecated options
-	deprecatedOptions := make([]string, 0)
 	walkPluginStruct(reflect.ValueOf(plugin), func(field reflect.StructField, value reflect.Value) {
 		// Try to report only those fields that are set
-		if value.IsZero() {
+		if !all && value.IsZero() {
 			return
 		}
 
@@ -55,28 +85,55 @@ func (c *Config) handleDeprecation(name string, plugin interface{}) error {
 		if len(tags) < 1 || tags[0] == "" {
 			return
 		}
-		since := tags[0]
-		notice := ""
-		if len(tags) > 1 {
-			notice = tags[1]
+		optionInfo := DeprecationInfo{
+			Name:  field.Name,
+			Since: tags[0],
+			Level: c.getDeprecationEscalation(tags[0]),
 		}
 
+		if len(tags) > 1 {
+			optionInfo.Notice = tags[1]
+		}
 		// Get the toml field name
 		option := field.Tag.Get("toml")
-		if option == "" {
-			option = field.Name
+		if option != "" {
+			optionInfo.Name = option
 		}
+		info.Options = append(info.Options, optionInfo)
+	})
+
+	return info
+}
+
+func (c *Config) printUserDeprecation(name string, plugin interface{}) error {
+	info := c.collectDeprecationInfo(name, plugin, false)
+
+	switch info.Level {
+	case Warn:
+		prefix := "W! " + color.YellowString("DeprecationWarning")
+		printPluginDeprecationNotice(prefix, info.Name, info.Since, info.Notice)
+		// We will not check for any deprecated options as the whole plugin is deprecated anyway.
+		return nil
+	case Error:
+		prefix := "E! " + color.RedString("DeprecationError")
+		printPluginDeprecationNotice(prefix, info.Name, info.Since, info.Notice)
+		// We are past the grace period
+		return fmt.Errorf("plugin deprecated")
+	}
 
-		switch c.getDeprecationEscalation(since) {
+	// Print deprecated options
+	deprecatedOptions := make([]string, 0)
+	for _, option := range info.Options {
+		switch option.Level {
 		case Warn:
 			prefix := "W! " + color.YellowString("DeprecationWarning")
-			printOptionDeprecationNotice(prefix, name, option, since, notice)
+			printOptionDeprecationNotice(prefix, info.Name, option.Name, option.Since, option.Notice)
 		case Error:
 			prefix := "E! " + color.RedString("DeprecationError")
-			printOptionDeprecationNotice(prefix, name, option, since, notice)
-			deprecatedOptions = append(deprecatedOptions, option)
+			printOptionDeprecationNotice(prefix, info.Name, option.Name, option.Since, option.Notice)
+			deprecatedOptions = append(deprecatedOptions, option.Name)
 		}
-	})
+	}
 
 	if len(deprecatedOptions) > 0 {
 		return fmt.Errorf("plugin options %q deprecated", strings.Join(deprecatedOptions, ","))
@@ -85,6 +142,71 @@ func (c *Config) handleDeprecation(name string, plugin interface{}) error {
 	return nil
 }
 
+func (c *Config) CollectDeprecationInfos() map[string][]PluginDeprecationInfo {
+	infos := make(map[string][]PluginDeprecationInfo)
+
+	infos["inputs"] = make([]PluginDeprecationInfo, 0)
+	for name, creator := range inputs.Inputs {
+		plugin := creator()
+		info := c.collectDeprecationInfo(name, plugin, true)
+
+		if info.Level != None || len(info.Options) > 0 {
+			infos["inputs"] = append(infos["inputs"], info)
+		}
+	}
+
+	infos["outputs"] = make([]PluginDeprecationInfo, 0)
+	for name, creator := range outputs.Outputs {
+		plugin := creator()
+		info := c.collectDeprecationInfo(name, plugin, true)
+
+		if info.Level != None || len(info.Options) > 0 {
+			infos["outputs"] = append(infos["outputs"], info)
+		}
+	}
+
+	infos["processors"] = make([]PluginDeprecationInfo, 0)
+	for name, creator := range processors.Processors {
+		plugin := creator()
+		info := c.collectDeprecationInfo(name, plugin, true)
+
+		if info.Level != None || len(info.Options) > 0 {
+			infos["processors"] = append(infos["processors"], info)
+		}
+	}
+
+	infos["aggregators"] = make([]PluginDeprecationInfo, 0)
+	for name, creator := range aggregators.Aggregators {
+		plugin := creator()
+		info := c.collectDeprecationInfo(name, plugin, true)
+
+		if info.Level != None || len(info.Options) > 0 {
+			infos["aggregators"] = append(infos["aggregators"], info)
+		}
+	}
+
+	return infos
+}
+
+func (c *Config) PrintDeprecationList(infos []PluginDeprecationInfo) {
+	sort.Slice(infos, func(i, j int) bool { return infos[i].Name < infos[j].Name })
+
+	for _, info := range infos {
+		switch info.Level {
+		case Warn, Error:
+			fmt.Printf("  %-40s %-5s since %5s %s\n", info.Name, info.Level, info.Since, info.Notice)
+		}
+
+		if len(info.Options) < 1 {
+			continue
+		}
+		sort.Slice(info.Options, func(i, j int) bool { return info.Options[i].Name < info.Options[j].Name })
+		for _, option := range info.Options {
+			fmt.Printf("  %-40s %-5s since %5s %s\n", info.Name+"/"+option.Name, option.Level, option.Since, option.Notice)
+		}
+	}
+}
+
 func (c *Config) getDeprecationEscalation(since string) Escalation {
 	sinceMajor, sinceMinor := parseVersion(since)
 	if c.versionMajor > sinceMajor {

From 03da7550992f7d6493a6e0122f6ff609963de4b3 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 19:42:37 +0200
Subject: [PATCH 12/45] Allow listing of deprecated plugins and options via
 telegraf cmd.

---
 cmd/telegraf/telegraf.go | 14 ++++++++++++++
 internal/usage.go        |  5 +++--
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/cmd/telegraf/telegraf.go b/cmd/telegraf/telegraf.go
index d7d5e444f36b1..b1b11b5839ebd 100644
--- a/cmd/telegraf/telegraf.go
+++ b/cmd/telegraf/telegraf.go
@@ -60,6 +60,8 @@ var fVersion = flag.Bool("version", false, "display the version and exit")
 var fSampleConfig = flag.Bool("sample-config", false,
 	"print out full sample configuration")
 var fPidfile = flag.String("pidfile", "", "file to write our pid to")
+var fDeprecationList = flag.Bool("deprecation-list", false,
+	"print all deprecated plugins or plugin options.")
 var fSectionFilters = flag.String("section-filter", "",
 	"filter the sections to print, separator is ':'. Valid values are 'agent', 'global_tags', 'outputs', 'processors', 'aggregators' and 'inputs'")
 var fInputFilters = flag.String("input-filter", "",
@@ -392,6 +394,18 @@ func main() {
 
 	// switch for flags which just do something and exit immediately
 	switch {
+	case *fDeprecationList:
+		c := config.NewConfig(version)
+		infos := c.CollectDeprecationInfos()
+		fmt.Println("Deprecated Input Plugins: ")
+		c.PrintDeprecationList(infos["inputs"])
+		fmt.Println("Deprecated Output Plugins: ")
+		c.PrintDeprecationList(infos["outputs"])
+		fmt.Println("Deprecated Processor Plugins: ")
+		c.PrintDeprecationList(infos["processors"])
+		fmt.Println("Deprecated Aggregator Plugins: ")
+		c.PrintDeprecationList(infos["aggregators"])
+		return
 	case *fOutputList:
 		fmt.Println("Available Output Plugins: ")
 		names := make([]string, 0, len(outputs.Outputs))
diff --git a/internal/usage.go b/internal/usage.go
index 916b5cb86e908..78e9a846b198b 100644
--- a/internal/usage.go
+++ b/internal/usage.go
@@ -17,13 +17,14 @@ The commands & flags are:
   --aggregator-filter <filter>   filter the aggregators to enable, separator is :
   --config <file>                configuration file to load
   --config-directory <directory> directory containing additional *.conf files
-  --watch-config                 Telegraf will restart on local config changes. Monitor changes 
-                                 using either fs notifications or polling.  Valid values: 'inotify' or 'poll'. 
+  --watch-config                 Telegraf will restart on local config changes. Monitor changes
+                                 using either fs notifications or polling.  Valid values: 'inotify' or 'poll'.
                                  Monitoring is off by default.
   --plugin-directory             directory containing *.so files, this directory will be
                                  searched recursively. Any Plugin found will be loaded
                                  and namespaced.
   --debug                        turn on debug logging
+  --deprecation-list             print all deprecated plugins or plugin options.
   --input-filter <filter>        filter the inputs to enable, separator is :
   --input-list                   print available input plugins.
   --output-filter <filter>       filter the outputs to enable, separator is :

From 9c4c1cd57abb2bfb7b1e08460c6a1669ae8a9c19 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 19:54:51 +0200
Subject: [PATCH 13/45] Restore the old config.NewConfig().

---
 cmd/telegraf/telegraf.go |  6 ++++--
 config/config.go         | 11 +++--------
 config/deprecation.go    |  8 ++++----
 3 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/cmd/telegraf/telegraf.go b/cmd/telegraf/telegraf.go
index b1b11b5839ebd..f8f361b0d3509 100644
--- a/cmd/telegraf/telegraf.go
+++ b/cmd/telegraf/telegraf.go
@@ -196,7 +196,8 @@ func runAgent(ctx context.Context,
 	log.Printf("I! Starting Telegraf %s", version)
 
 	// If no other options are specified, load the config file and run.
-	c := config.NewConfig(version)
+	c := config.NewConfig()
+	c.VersionMajor, c.VersionMinor = config.ParseVersion(version)
 	c.OutputFilters = outputFilters
 	c.InputFilters = inputFilters
 	var err error
@@ -395,7 +396,8 @@ func main() {
 	// switch for flags which just do something and exit immediately
 	switch {
 	case *fDeprecationList:
-		c := config.NewConfig(version)
+		c := config.NewConfig()
+		c.VersionMajor, c.VersionMinor = config.ParseVersion(version)
 		infos := c.CollectDeprecationInfos()
 		fmt.Println("Deprecated Input Plugins: ")
 		c.PrintDeprecationList(infos["inputs"])
diff --git a/config/config.go b/config/config.go
index 5f8f7c59f34f2..13f25ba1649f9 100644
--- a/config/config.go
+++ b/config/config.go
@@ -78,16 +78,14 @@ type Config struct {
 	Processors    models.RunningProcessors
 	AggProcessors models.RunningProcessors
 
-	versionMajor int
-	versionMinor int
+	VersionMajor int
+	VersionMinor int
 }
 
 // NewConfig creates a new struct to hold the Telegraf config.
 // For historical reasons, It holds the actual instances of the running plugins
 // once the configuration is parsed.
-func NewConfig(version string) *Config {
-	maj, min := parseVersion(version)
-
+func NewConfig() *Config {
 	c := &Config{
 		UnusedFields: map[string]bool{},
 
@@ -107,9 +105,6 @@ func NewConfig(version string) *Config {
 		AggProcessors: make([]*models.RunningProcessor, 0),
 		InputFilters:  make([]string, 0),
 		OutputFilters: make([]string, 0),
-
-		versionMajor: maj,
-		versionMinor: min,
 	}
 
 	tomlCfg := &toml.Config{
diff --git a/config/deprecation.go b/config/deprecation.go
index 18341b0222891..90d80feb1db8d 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -208,11 +208,11 @@ func (c *Config) PrintDeprecationList(infos []PluginDeprecationInfo) {
 }
 
 func (c *Config) getDeprecationEscalation(since string) Escalation {
-	sinceMajor, sinceMinor := parseVersion(since)
-	if c.versionMajor > sinceMajor {
+	sinceMajor, sinceMinor := ParseVersion(since)
+	if c.VersionMajor > sinceMajor {
 		return Error
 	}
-	if c.versionMajor == sinceMajor && c.versionMinor >= sinceMinor {
+	if c.VersionMajor == sinceMajor && c.VersionMinor >= sinceMinor {
 		return Warn
 	}
 
@@ -266,7 +266,7 @@ func walkPluginStruct(value reflect.Value, fn func(f reflect.StructField, fv ref
 	}
 }
 
-func parseVersion(version string) (major, minor int) {
+func ParseVersion(version string) (major, minor int) {
 	parts := strings.SplitN(version, ".", 3)
 	if len(parts) < 2 {
 		panic(fmt.Errorf("insufficient version fields in %q", version))

From f6d5db3aff4ac5b7581fad7267217a14603091e0 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Mon, 4 Oct 2021 20:07:00 +0200
Subject: [PATCH 14/45] Fix linter issues.

---
 cmd/telegraf/telegraf.go                                    | 4 ++++
 config/config.go                                            | 3 ---
 config/deprecation.go                                       | 6 +++---
 plugins/inputs/cassandra/cassandra.go                       | 2 +-
 plugins/inputs/http_listener_v2/http_listener_v2.go         | 2 +-
 plugins/inputs/httpjson/httpjson.go                         | 2 +-
 plugins/inputs/jolokia/jolokia.go                           | 2 +-
 .../inputs/kafka_consumer_legacy/kafka_consumer_legacy.go   | 2 +-
 plugins/inputs/logparser/logparser.go                       | 2 +-
 plugins/inputs/snmp_legacy/snmp_legacy.go                   | 2 +-
 plugins/inputs/tcp_listener/tcp_listener.go                 | 2 +-
 plugins/inputs/udp_listener/udp_listener.go                 | 2 +-
 plugins/outputs/riemann_legacy/riemann.go                   | 2 +-
 13 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/cmd/telegraf/telegraf.go b/cmd/telegraf/telegraf.go
index f8f361b0d3509..c4cb5dd3d613b 100644
--- a/cmd/telegraf/telegraf.go
+++ b/cmd/telegraf/telegraf.go
@@ -399,12 +399,16 @@ func main() {
 		c := config.NewConfig()
 		c.VersionMajor, c.VersionMinor = config.ParseVersion(version)
 		infos := c.CollectDeprecationInfos()
+		//nolint:revive // We will notice if Println fails
 		fmt.Println("Deprecated Input Plugins: ")
 		c.PrintDeprecationList(infos["inputs"])
+		//nolint:revive // We will notice if Println fails
 		fmt.Println("Deprecated Output Plugins: ")
 		c.PrintDeprecationList(infos["outputs"])
+		//nolint:revive // We will notice if Println fails
 		fmt.Println("Deprecated Processor Plugins: ")
 		c.PrintDeprecationList(infos["processors"])
+		//nolint:revive // We will notice if Println fails
 		fmt.Println("Deprecated Aggregator Plugins: ")
 		c.PrintDeprecationList(infos["aggregators"])
 		return
diff --git a/config/config.go b/config/config.go
index 13f25ba1649f9..3723ad61dc993 100644
--- a/config/config.go
+++ b/config/config.go
@@ -203,9 +203,6 @@ type AgentConfig struct {
 
 	Hostname     string
 	OmitHostname bool
-
-	versionMajor int
-	versionMinor int
 }
 
 // InputNames returns a list of strings of the configured inputs.
diff --git a/config/deprecation.go b/config/deprecation.go
index 90d80feb1db8d..01c9314dfc15f 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -2,7 +2,7 @@ package config
 
 import (
 	"fmt"
-	"log"
+	"log" //nolint:revive // log is ok here as the logging facility is not set-up yet
 	"reflect"
 	"sort"
 	"strconv"
@@ -194,7 +194,7 @@ func (c *Config) PrintDeprecationList(infos []PluginDeprecationInfo) {
 	for _, info := range infos {
 		switch info.Level {
 		case Warn, Error:
-			fmt.Printf("  %-40s %-5s since %5s %s\n", info.Name, info.Level, info.Since, info.Notice)
+			_, _ = fmt.Printf("  %-40s %-5s since %5s %s\n", info.Name, info.Level, info.Since, info.Notice)
 		}
 
 		if len(info.Options) < 1 {
@@ -202,7 +202,7 @@ func (c *Config) PrintDeprecationList(infos []PluginDeprecationInfo) {
 		}
 		sort.Slice(info.Options, func(i, j int) bool { return info.Options[i].Name < info.Options[j].Name })
 		for _, option := range info.Options {
-			fmt.Printf("  %-40s %-5s since %5s %s\n", info.Name+"/"+option.Name, option.Level, option.Since, option.Notice)
+			_, _ = fmt.Printf("  %-40s %-5s since %5s %s\n", info.Name+"/"+option.Name, option.Level, option.Since, option.Notice)
 		}
 	}
 }
diff --git a/plugins/inputs/cassandra/cassandra.go b/plugins/inputs/cassandra/cassandra.go
index 96b6d9bf46ed7..456ec93fa2f86 100644
--- a/plugins/inputs/cassandra/cassandra.go
+++ b/plugins/inputs/cassandra/cassandra.go
@@ -313,7 +313,7 @@ func (c *Cassandra) Gather(acc telegraf.Accumulator) error {
 	return nil
 }
 
-func (_ *Cassandra) DeprecationNotice() (since, notice string) {
+func (*Cassandra) DeprecationNotice() (since, notice string) {
 	return "1.7", "use 'inputs.jolokia2' with the 'cassandra.conf' example configuration instead"
 }
 
diff --git a/plugins/inputs/http_listener_v2/http_listener_v2.go b/plugins/inputs/http_listener_v2/http_listener_v2.go
index f62d59e929cff..92a7670098a59 100644
--- a/plugins/inputs/http_listener_v2/http_listener_v2.go
+++ b/plugins/inputs/http_listener_v2/http_listener_v2.go
@@ -385,7 +385,7 @@ func (h *HTTPListenerV2) authenticateIfSet(handler http.HandlerFunc, res http.Re
 	}
 }
 
-func (_ *HTTPListenerV2) DeprecationNotice() (since, notice string) {
+func (*HTTPListenerV2) DeprecationNotice() (since, notice string) {
 	return "1.9", "has been renamed to 'influxdb_listener', use 'inputs.influxdb_listener' or 'inputs.influxdb_listener_v2' instead"
 }
 
diff --git a/plugins/inputs/httpjson/httpjson.go b/plugins/inputs/httpjson/httpjson.go
index 77d3636138616..4ca87fa46c1d8 100644
--- a/plugins/inputs/httpjson/httpjson.go
+++ b/plugins/inputs/httpjson/httpjson.go
@@ -283,7 +283,7 @@ func (h *HTTPJSON) sendRequest(serverURL string) (string, float64, error) {
 	return string(body), responseTime, err
 }
 
-func (_ *HTTPJSON) DeprecationNotice() (since, notice string) {
+func (*HTTPJSON) DeprecationNotice() (since, notice string) {
 	return "1.6", "use 'inputs.http' instead"
 }
 
diff --git a/plugins/inputs/jolokia/jolokia.go b/plugins/inputs/jolokia/jolokia.go
index cb39ca25764ed..97f4afcadf503 100644
--- a/plugins/inputs/jolokia/jolokia.go
+++ b/plugins/inputs/jolokia/jolokia.go
@@ -318,7 +318,7 @@ func (j *Jolokia) Gather(acc telegraf.Accumulator) error {
 	return nil
 }
 
-func (_ *Jolokia) DeprecationNotice() (since, notice string) {
+func (*Jolokia) DeprecationNotice() (since, notice string) {
 	return "1.5", "use 'inputs.jolokia2' instead"
 }
 
diff --git a/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go b/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go
index 3803808d9cd1c..041bf2783d25f 100644
--- a/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go
+++ b/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go
@@ -184,7 +184,7 @@ func (k *Kafka) Gather(_ telegraf.Accumulator) error {
 	return nil
 }
 
-func (_ *Kafka) DeprecationNotice() (since, notice string) {
+func (*Kafka) DeprecationNotice() (since, notice string) {
 	return "1.20", "use 'inputs.kafka_consumer' instead, NOTE: 'kafka_consumer' only supports Kafka v0.8+"
 }
 
diff --git a/plugins/inputs/logparser/logparser.go b/plugins/inputs/logparser/logparser.go
index 017ee6868a968..486acb957cdab 100644
--- a/plugins/inputs/logparser/logparser.go
+++ b/plugins/inputs/logparser/logparser.go
@@ -360,7 +360,7 @@ func (l *LogParserPlugin) Stop() {
 	offsetsMutex.Unlock()
 }
 
-func (_ *LogParserPlugin) DeprecationNotice() (since, notice string) {
+func (*LogParserPlugin) DeprecationNotice() (since, notice string) {
 	return "1.15", "use 'inputs.tail' with 'grok' data format instead"
 }
 
diff --git a/plugins/inputs/snmp_legacy/snmp_legacy.go b/plugins/inputs/snmp_legacy/snmp_legacy.go
index ddbb4d276c1dd..2ee19768a65b9 100644
--- a/plugins/inputs/snmp_legacy/snmp_legacy.go
+++ b/plugins/inputs/snmp_legacy/snmp_legacy.go
@@ -815,7 +815,7 @@ func (h *Host) HandleResponse(
 	return lastOid, nil
 }
 
-func (_ *Snmp) DeprecationNotice() (since, notice string) {
+func (*Snmp) DeprecationNotice() (since, notice string) {
 	return "1.20", "use 'inputs.snmp' instead"
 }
 
diff --git a/plugins/inputs/tcp_listener/tcp_listener.go b/plugins/inputs/tcp_listener/tcp_listener.go
index f591149a7c556..499f57a7be913 100644
--- a/plugins/inputs/tcp_listener/tcp_listener.go
+++ b/plugins/inputs/tcp_listener/tcp_listener.go
@@ -297,7 +297,7 @@ func (t *TCPListener) remember(id string, conn *net.TCPConn) {
 	t.conns[id] = conn
 }
 
-func (_ *TCPListener) DeprecationNotice() (since, notice string) {
+func (*TCPListener) DeprecationNotice() (since, notice string) {
 	return "1.3", "use 'inputs.socket_listener' instead"
 }
 
diff --git a/plugins/inputs/udp_listener/udp_listener.go b/plugins/inputs/udp_listener/udp_listener.go
index 8184b114062d2..d9eda53955399 100644
--- a/plugins/inputs/udp_listener/udp_listener.go
+++ b/plugins/inputs/udp_listener/udp_listener.go
@@ -221,7 +221,7 @@ func (u *UDPListener) udpParser() {
 	}
 }
 
-func (_ *UDPListener) DeprecationNotice() (since, notice string) {
+func (*UDPListener) DeprecationNotice() (since, notice string) {
 	return "1.3", "use 'inputs.socket_listener' instead"
 }
 
diff --git a/plugins/outputs/riemann_legacy/riemann.go b/plugins/outputs/riemann_legacy/riemann.go
index e071928a931c9..ff03feac63410 100644
--- a/plugins/outputs/riemann_legacy/riemann.go
+++ b/plugins/outputs/riemann_legacy/riemann.go
@@ -147,7 +147,7 @@ func serviceName(s string, n string, t map[string]string, f string) string {
 	return strings.Join(serviceStrings, s)
 }
 
-func (_ *Riemann) DeprecationNotice() (since, notice string) {
+func (*Riemann) DeprecationNotice() (since, notice string) {
 	return "1.20", "use 'outputs.riemann' instead (see https://github.com/influxdata/telegraf/issues/1878)"
 }
 

From 0792b914f0efd56ad3e826fe4013cc8b2f1cbad2 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Tue, 5 Oct 2021 11:07:15 +0200
Subject: [PATCH 15/45] Make tidy.

---
 go.mod | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/go.mod b/go.mod
index 75496c6646c71..b12d45dbb1ab2 100644
--- a/go.mod
+++ b/go.mod
@@ -98,7 +98,7 @@ require (
 	github.com/eapache/queue v1.1.0 // indirect
 	github.com/echlebek/timeproxy v1.0.0 // indirect
 	github.com/eclipse/paho.mqtt.golang v1.3.0
-	github.com/fatih/color v1.10.0 // indirect
+	github.com/fatih/color v1.10.0
 	github.com/form3tech-oss/jwt-go v3.2.5+incompatible // indirect
 	github.com/ghodss/yaml v1.0.1-0.20190212211648-25d852aebe32
 	github.com/go-logfmt/logfmt v0.5.0

From 4e6e293c89477190bbac3a71b44d18e3eddbc2c8 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Tue, 5 Oct 2021 11:09:24 +0200
Subject: [PATCH 16/45] Add comment to walkPluginStruct().

---
 config/deprecation.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/config/deprecation.go b/config/deprecation.go
index 01c9314dfc15f..a28366b954fea 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -237,6 +237,9 @@ func printOptionDeprecationNotice(prefix, name, option, since, notice string) {
 	log.Printf("Please note: %s", optionWarnNotice)
 }
 
+
+// walkPluginStruct iterates over the fields of a structure in depth-first search (to cover nested structures)
+// and calls the given function for every visited field.
 func walkPluginStruct(value reflect.Value, fn func(f reflect.StructField, fv reflect.Value)) {
 	v := reflect.Indirect(value)
 	t := v.Type()

From b83dc36d4ec62f99308f4097b5766d1f6dc7980f Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Tue, 5 Oct 2021 11:17:56 +0200
Subject: [PATCH 17/45] Pimp walkPluginStruct() to also walk structs embedded
 in slices/arrays and maps.

---
 config/deprecation.go | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index a28366b954fea..76df02559b4d5 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -237,13 +237,20 @@ func printOptionDeprecationNotice(prefix, name, option, since, notice string) {
 	log.Printf("Please note: %s", optionWarnNotice)
 }
 
-
 // walkPluginStruct iterates over the fields of a structure in depth-first search (to cover nested structures)
 // and calls the given function for every visited field.
 func walkPluginStruct(value reflect.Value, fn func(f reflect.StructField, fv reflect.Value)) {
 	v := reflect.Indirect(value)
 	t := v.Type()
 
+	// Only works on structs
+	if t.Kind() != reflect.Struct {
+		return
+	}
+
+	// Walk over the struct fields and call the given function. If we encounter more complex embedded
+	// elements (stucts, slices/arrays, maps) we need to descend into those elements as they might
+	// contain structures nested in the current structure.
 	for i := 0; i < t.NumField(); i++ {
 		field := t.Field(i)
 		fieldValue := v.Field(i)
@@ -254,15 +261,20 @@ func walkPluginStruct(value reflect.Value, fn func(f reflect.StructField, fv ref
 		switch field.Type.Kind() {
 		case reflect.Struct:
 			walkPluginStruct(fieldValue, fn)
-
 		case reflect.Array, reflect.Slice:
 			for j := 0; j < fieldValue.Len(); j++ {
-				fn(field, fieldValue.Index(j))
+				element := fieldValue.Index(j)
+				// The array might contain structs
+				walkPluginStruct(element, fn)
+				fn(field, element)
 			}
 		case reflect.Map:
 			iter := fieldValue.MapRange()
 			for iter.Next() {
-				fn(field, iter.Value())
+				element := iter.Value()
+				// The map might contain structs
+				walkPluginStruct(element, fn)
+				fn(field, element)
 			}
 		}
 		fn(field, fieldValue)

From 75ee66d7f6fa317e1757370bccac60c32119dfd2 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Wed, 13 Oct 2021 15:12:50 +0200
Subject: [PATCH 18/45] Print deprecation statistics which is also included in
 a log-file if configured.

---
 cmd/telegraf/telegraf.go | 13 +++++++++++++
 config/config.go         | 10 ++++++----
 config/deprecation.go    | 39 +++++++++++++++++++++++++++++++--------
 3 files changed, 50 insertions(+), 12 deletions(-)

diff --git a/cmd/telegraf/telegraf.go b/cmd/telegraf/telegraf.go
index c4cb5dd3d613b..02cbc8b641da7 100644
--- a/cmd/telegraf/telegraf.go
+++ b/cmd/telegraf/telegraf.go
@@ -273,6 +273,19 @@ func runAgent(ctx context.Context,
 	log.Printf("I! Loaded outputs: %s", strings.Join(c.OutputNames(), " "))
 	log.Printf("I! Tags enabled: %s", c.ListTags())
 
+	if count, found := c.Deprecations["inputs"]; found && (count[0] > 0 || count[1] > 0) {
+		log.Printf("W! Deprecated inputs: %d and %d options", count[0], count[1])
+	}
+	if count, found := c.Deprecations["aggregators"]; found && (count[0] > 0 || count[1] > 0) {
+		log.Printf("W! Deprecated aggregators: %d and %d options", count[0], count[1])
+	}
+	if count, found := c.Deprecations["processors"]; found && (count[0] > 0 || count[1] > 0) {
+		log.Printf("W! Deprecated processors: %d and %d options", count[0], count[1])
+	}
+	if count, found := c.Deprecations["outputs"]; found && (count[0] > 0 || count[1] > 0) {
+		log.Printf("W! Deprecated outputs: %d and %d options", count[0], count[1])
+	}
+
 	if *fPidfile != "" {
 		f, err := os.OpenFile(*fPidfile, os.O_CREATE|os.O_WRONLY, 0644)
 		if err != nil {
diff --git a/config/config.go b/config/config.go
index 3723ad61dc993..da512e89699c4 100644
--- a/config/config.go
+++ b/config/config.go
@@ -80,6 +80,7 @@ type Config struct {
 
 	VersionMajor int
 	VersionMinor int
+	Deprecations map[string][]int64
 }
 
 // NewConfig creates a new struct to hold the Telegraf config.
@@ -105,6 +106,7 @@ func NewConfig() *Config {
 		AggProcessors: make([]*models.RunningProcessor, 0),
 		InputFilters:  make([]string, 0),
 		OutputFilters: make([]string, 0),
+		Deprecations:  make(map[string][]int64, 0),
 	}
 
 	tomlCfg := &toml.Config{
@@ -1025,7 +1027,7 @@ func (c *Config) addAggregator(name string, table *ast.Table) error {
 		return err
 	}
 
-	if err := c.printUserDeprecation("aggregators."+name, aggregator); err != nil {
+	if err := c.printUserDeprecation("aggregators", name, aggregator); err != nil {
 		return err
 	}
 
@@ -1077,7 +1079,7 @@ func (c *Config) newRunningProcessor(
 		}
 	}
 
-	if err := c.printUserDeprecation("processors."+processorConfig.Name, processor); err != nil {
+	if err := c.printUserDeprecation("processors", processorConfig.Name, processor); err != nil {
 		return nil, err
 	}
 
@@ -1115,7 +1117,7 @@ func (c *Config) addOutput(name string, table *ast.Table) error {
 		return err
 	}
 
-	if err := c.printUserDeprecation("outputs."+name, output); err != nil {
+	if err := c.printUserDeprecation("outputs", name, output); err != nil {
 		return err
 	}
 
@@ -1168,7 +1170,7 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 		return err
 	}
 
-	if err := c.printUserDeprecation("inputs."+name, input); err != nil {
+	if err := c.printUserDeprecation("inputs", name, input); err != nil {
 		return err
 	}
 
diff --git a/config/deprecation.go b/config/deprecation.go
index 76df02559b4d5..ffdbc97932c92 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -64,14 +64,33 @@ type PluginDeprecationInfo struct {
 	Options []DeprecationInfo
 }
 
-func (c *Config) collectDeprecationInfo(name string, plugin interface{}, all bool) PluginDeprecationInfo {
+func (c *Config) incrementPluginDeprecations(category string) {
+	newcounts := []int64{1, 0}
+	if counts, found := c.Deprecations[category]; found {
+		newcounts = []int64{counts[0] + 1, counts[1]}
+	}
+	c.Deprecations[category] = newcounts
+}
+
+func (c *Config) incrementPluginOptionDeprecations(category string) {
+	newcounts := []int64{0, 1}
+	if counts, found := c.Deprecations[category]; found {
+		newcounts = []int64{counts[0], counts[1] + 1}
+	}
+	c.Deprecations[category] = newcounts
+}
+
+func (c *Config) collectDeprecationInfo(category, name string, plugin interface{}, all bool) PluginDeprecationInfo {
 	info := PluginDeprecationInfo{}
-	info.Name = name
+	info.Name = category + "." + name
 
 	// First check if the whole plugin is deprecated
 	if deprecatedPlugin, ok := plugin.(telegraf.PluginDeprecator); ok {
 		info.Since, info.Notice = deprecatedPlugin.DeprecationNotice()
 		info.Level = c.getDeprecationEscalation(info.Since)
+		if info.Level != None {
+			c.incrementPluginDeprecations(category)
+		}
 	}
 
 	// Check for deprecated options
@@ -91,6 +110,10 @@ func (c *Config) collectDeprecationInfo(name string, plugin interface{}, all boo
 			Level: c.getDeprecationEscalation(tags[0]),
 		}
 
+		if optionInfo.Level != None {
+			c.incrementPluginOptionDeprecations(category)
+		}
+
 		if len(tags) > 1 {
 			optionInfo.Notice = tags[1]
 		}
@@ -105,8 +128,8 @@ func (c *Config) collectDeprecationInfo(name string, plugin interface{}, all boo
 	return info
 }
 
-func (c *Config) printUserDeprecation(name string, plugin interface{}) error {
-	info := c.collectDeprecationInfo(name, plugin, false)
+func (c *Config) printUserDeprecation(category, name string, plugin interface{}) error {
+	info := c.collectDeprecationInfo(category, name, plugin, false)
 
 	switch info.Level {
 	case Warn:
@@ -148,7 +171,7 @@ func (c *Config) CollectDeprecationInfos() map[string][]PluginDeprecationInfo {
 	infos["inputs"] = make([]PluginDeprecationInfo, 0)
 	for name, creator := range inputs.Inputs {
 		plugin := creator()
-		info := c.collectDeprecationInfo(name, plugin, true)
+		info := c.collectDeprecationInfo("inputs", name, plugin, true)
 
 		if info.Level != None || len(info.Options) > 0 {
 			infos["inputs"] = append(infos["inputs"], info)
@@ -158,7 +181,7 @@ func (c *Config) CollectDeprecationInfos() map[string][]PluginDeprecationInfo {
 	infos["outputs"] = make([]PluginDeprecationInfo, 0)
 	for name, creator := range outputs.Outputs {
 		plugin := creator()
-		info := c.collectDeprecationInfo(name, plugin, true)
+		info := c.collectDeprecationInfo("outputs", name, plugin, true)
 
 		if info.Level != None || len(info.Options) > 0 {
 			infos["outputs"] = append(infos["outputs"], info)
@@ -168,7 +191,7 @@ func (c *Config) CollectDeprecationInfos() map[string][]PluginDeprecationInfo {
 	infos["processors"] = make([]PluginDeprecationInfo, 0)
 	for name, creator := range processors.Processors {
 		plugin := creator()
-		info := c.collectDeprecationInfo(name, plugin, true)
+		info := c.collectDeprecationInfo("processors", name, plugin, true)
 
 		if info.Level != None || len(info.Options) > 0 {
 			infos["processors"] = append(infos["processors"], info)
@@ -178,7 +201,7 @@ func (c *Config) CollectDeprecationInfos() map[string][]PluginDeprecationInfo {
 	infos["aggregators"] = make([]PluginDeprecationInfo, 0)
 	for name, creator := range aggregators.Aggregators {
 		plugin := creator()
-		info := c.collectDeprecationInfo(name, plugin, true)
+		info := c.collectDeprecationInfo("aggregators", name, plugin, true)
 
 		if info.Level != None || len(info.Options) > 0 {
 			infos["aggregators"] = append(infos["aggregators"], info)

From 246a650fb47cc40a85ce348b51695cfc5613cc75 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Wed, 13 Oct 2021 15:19:37 +0200
Subject: [PATCH 19/45] Enable plugin filtering for deprecation list.

---
 cmd/telegraf/telegraf.go |  7 ++++++-
 config/deprecation.go    | 18 +++++++++++++++++-
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/cmd/telegraf/telegraf.go b/cmd/telegraf/telegraf.go
index 02cbc8b641da7..4dd2b5a1c19f0 100644
--- a/cmd/telegraf/telegraf.go
+++ b/cmd/telegraf/telegraf.go
@@ -411,7 +411,12 @@ func main() {
 	case *fDeprecationList:
 		c := config.NewConfig()
 		c.VersionMajor, c.VersionMinor = config.ParseVersion(version)
-		infos := c.CollectDeprecationInfos()
+		infos := c.CollectDeprecationInfos(
+			inputFilters,
+			outputFilters,
+			aggregatorFilters,
+			processorFilters,
+		)
 		//nolint:revive // We will notice if Println fails
 		fmt.Println("Deprecated Input Plugins: ")
 		c.PrintDeprecationList(infos["inputs"])
diff --git a/config/deprecation.go b/config/deprecation.go
index ffdbc97932c92..ebdf330a7b471 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -165,11 +165,15 @@ func (c *Config) printUserDeprecation(category, name string, plugin interface{})
 	return nil
 }
 
-func (c *Config) CollectDeprecationInfos() map[string][]PluginDeprecationInfo {
+func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFilter []string) map[string][]PluginDeprecationInfo {
 	infos := make(map[string][]PluginDeprecationInfo)
 
 	infos["inputs"] = make([]PluginDeprecationInfo, 0)
 	for name, creator := range inputs.Inputs {
+		if len(inFilter) > 0 && !sliceContains(name, inFilter) {
+			continue
+		}
+
 		plugin := creator()
 		info := c.collectDeprecationInfo("inputs", name, plugin, true)
 
@@ -180,6 +184,10 @@ func (c *Config) CollectDeprecationInfos() map[string][]PluginDeprecationInfo {
 
 	infos["outputs"] = make([]PluginDeprecationInfo, 0)
 	for name, creator := range outputs.Outputs {
+		if len(outFilter) > 0 && !sliceContains(name, outFilter) {
+			continue
+		}
+
 		plugin := creator()
 		info := c.collectDeprecationInfo("outputs", name, plugin, true)
 
@@ -190,6 +198,10 @@ func (c *Config) CollectDeprecationInfos() map[string][]PluginDeprecationInfo {
 
 	infos["processors"] = make([]PluginDeprecationInfo, 0)
 	for name, creator := range processors.Processors {
+		if len(procFilter) > 0 && !sliceContains(name, procFilter) {
+			continue
+		}
+
 		plugin := creator()
 		info := c.collectDeprecationInfo("processors", name, plugin, true)
 
@@ -200,6 +212,10 @@ func (c *Config) CollectDeprecationInfos() map[string][]PluginDeprecationInfo {
 
 	infos["aggregators"] = make([]PluginDeprecationInfo, 0)
 	for name, creator := range aggregators.Aggregators {
+		if len(aggFilter) > 0 && !sliceContains(name, aggFilter) {
+			continue
+		}
+
 		plugin := creator()
 		info := c.collectDeprecationInfo("aggregators", name, plugin, true)
 

From 1d09c2e34793d7bea883ea4b81bb4ef413538cee Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 14 Oct 2021 10:02:51 +0200
Subject: [PATCH 20/45] Add new command-line flag to documentation.

---
 docs/COMMANDS_AND_FLAGS.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/COMMANDS_AND_FLAGS.md b/docs/COMMANDS_AND_FLAGS.md
index babccb54ba152..b575b1a6f527c 100644
--- a/docs/COMMANDS_AND_FLAGS.md
+++ b/docs/COMMANDS_AND_FLAGS.md
@@ -24,6 +24,7 @@ telegraf [flags]
 |`--watch-config`                 |Telegraf will restart on local config changes. Monitor changes using either fs notifications or polling. Valid values: `inotify` or `poll`. Monitoring is off by default.|
 |`--plugin-directory`             |directory containing *.so files, this directory will be searched recursively. Any Plugin found will be loaded and namespaced.|
 |`--debug`                        |turn on debug logging|
+|`--deprecation-list`            |print all deprecated plugins or plugin options|
 |`--input-filter <filter>`        |filter the inputs to enable, separator is `:`|
 |`--input-list`                   |print available input plugins.|
 |`--output-filter <filter>`       |filter the outputs to enable, separator is `:`|

From 86e559bb4563348001b2e4b88b8ffd4a455f8d98 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Fri, 15 Oct 2021 13:03:20 +0200
Subject: [PATCH 21/45] Fix doc alignment.

---
 docs/COMMANDS_AND_FLAGS.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/COMMANDS_AND_FLAGS.md b/docs/COMMANDS_AND_FLAGS.md
index b575b1a6f527c..9a57a0b832bd7 100644
--- a/docs/COMMANDS_AND_FLAGS.md
+++ b/docs/COMMANDS_AND_FLAGS.md
@@ -24,7 +24,7 @@ telegraf [flags]
 |`--watch-config`                 |Telegraf will restart on local config changes. Monitor changes using either fs notifications or polling. Valid values: `inotify` or `poll`. Monitoring is off by default.|
 |`--plugin-directory`             |directory containing *.so files, this directory will be searched recursively. Any Plugin found will be loaded and namespaced.|
 |`--debug`                        |turn on debug logging|
-|`--deprecation-list`            |print all deprecated plugins or plugin options|
+|`--deprecation-list`             |print all deprecated plugins or plugin options|
 |`--input-filter <filter>`        |filter the inputs to enable, separator is `:`|
 |`--input-list`                   |print available input plugins.|
 |`--output-filter <filter>`       |filter the outputs to enable, separator is `:`|

From 43079aee67d8928fca13e157c58ba4b493ff2f6d Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Fri, 15 Oct 2021 13:04:29 +0200
Subject: [PATCH 22/45] Fix linter error.

---
 config/config.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config/config.go b/config/config.go
index da512e89699c4..affba30b2ae38 100644
--- a/config/config.go
+++ b/config/config.go
@@ -106,7 +106,7 @@ func NewConfig() *Config {
 		AggProcessors: make([]*models.RunningProcessor, 0),
 		InputFilters:  make([]string, 0),
 		OutputFilters: make([]string, 0),
-		Deprecations:  make(map[string][]int64, 0),
+		Deprecations:  make(map[string][]int64),
 	}
 
 	tomlCfg := &toml.Config{

From 529557d2883f7c9120bd1374422b3f9a3ab8eae6 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Tue, 9 Nov 2021 18:47:22 +0100
Subject: [PATCH 23/45] Implement discussed deprecation strategy and allow to
 specify a custom removal version.

---
 config/deprecation.go               | 138 ++++++++++++++++------------
 plugin.go                           |   2 +-
 plugins/inputs/httpjson/httpjson.go |   4 +-
 3 files changed, 81 insertions(+), 63 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index ebdf330a7b471..4d16a34ba182e 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -17,11 +17,6 @@ import (
 	"github.com/influxdata/telegraf/plugins/processors"
 )
 
-const (
-	pluginWarnNotice = "Deprecated plugin will be removed soon, please switch to a supported plugin!"
-	optionWarnNotice = "Deprecated options will be removed with the next major version, please adapt your config!"
-)
-
 // Escalation level for the plugin or option
 type Escalation int
 
@@ -44,24 +39,73 @@ const (
 	Error
 )
 
-// DeprecationInfo contains all important information to describe a deprecated entity
-type DeprecationInfo struct {
+// deprecationInfo contains all important information to describe a deprecated entity
+type deprecationInfo struct {
 	// Name of the plugin or plugin option
 	Name string
 	// Level of deprecation
 	Level Escalation
 	// Since which version the plugin or plugin option is deprecated
 	Since string
+	// RemovalIn is an optional field denoting in which version the plugin or plugin option is actually removed
+	RemovalIn string
 	// Notice to the user about alternatives or further information
 	Notice string
 }
 
-// PluginDeprecationInfo holds all information about a deprecated plugin or it's options
-type PluginDeprecationInfo struct {
-	DeprecationInfo
+func (di *deprecationInfo) determineEscalation(major, minor int) {
+	var removalMajor, removalMinor int
+
+	sinceMajor, sinceMinor := ParseVersion(di.Since)
+	if di.RemovalIn != "" {
+		removalMajor, removalMinor = ParseVersion(di.RemovalIn)
+	} else {
+		removalMajor, removalMinor = sinceMajor+1, 0
+		di.RemovalIn = fmt.Sprintf("%d.%d", removalMajor, removalMinor)
+	}
+
+	di.Level = None
+	if major > removalMajor || (major == removalMajor && minor >= removalMinor) {
+		di.Level = Error
+	} else if major > sinceMajor || (major == sinceMajor && minor >= sinceMinor) {
+		di.Level = Warn
+	}
+}
+
+func (di *deprecationInfo) printPluginDeprecationNotice(prefix string) {
+	if di.Notice != "" {
+		log.Printf(
+			"%s: Plugin %q deprecated since version %s and will be removed in %s: %s",
+			prefix, di.Name, di.Since, di.RemovalIn, di.Notice,
+		)
+	} else {
+		log.Printf(
+			"%s: Plugin %q deprecated since version %s and will be removed in %s",
+			prefix, di.Name, di.Since, di.RemovalIn,
+		)
+	}
+}
+
+func (di *deprecationInfo) printOptionDeprecationNotice(prefix, plugin string) {
+	if di.Notice != "" {
+		log.Printf(
+			"%s: Option %q of plugin %q deprecated since version %s and will be removed in %s: %s",
+			prefix, di.Name, plugin, di.Since, di.RemovalIn, di.Notice,
+		)
+	} else {
+		log.Printf(
+			"%s: Option %q of plugin %q deprecated since version %s and will be removed in %s",
+			prefix, di.Name, plugin, di.Since, di.RemovalIn,
+		)
+	}
+}
+
+// pluginDeprecationInfo holds all information about a deprecated plugin or it's options
+type pluginDeprecationInfo struct {
+	deprecationInfo
 
 	// Options deprecated for this plugin
-	Options []DeprecationInfo
+	Options []deprecationInfo
 }
 
 func (c *Config) incrementPluginDeprecations(category string) {
@@ -80,14 +124,14 @@ func (c *Config) incrementPluginOptionDeprecations(category string) {
 	c.Deprecations[category] = newcounts
 }
 
-func (c *Config) collectDeprecationInfo(category, name string, plugin interface{}, all bool) PluginDeprecationInfo {
-	info := PluginDeprecationInfo{}
+func (c *Config) collectDeprecationInfo(category, name string, plugin interface{}, all bool) pluginDeprecationInfo {
+	info := pluginDeprecationInfo{}
 	info.Name = category + "." + name
 
 	// First check if the whole plugin is deprecated
 	if deprecatedPlugin, ok := plugin.(telegraf.PluginDeprecator); ok {
-		info.Since, info.Notice = deprecatedPlugin.DeprecationNotice()
-		info.Level = c.getDeprecationEscalation(info.Since)
+		info.Since, info.RemovalIn, info.Notice = deprecatedPlugin.DeprecationNotice()
+		info.determineEscalation(c.VersionMajor, c.VersionMinor)
 		if info.Level != None {
 			c.incrementPluginDeprecations(category)
 		}
@@ -100,14 +144,13 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 			return
 		}
 
-		tags := strings.SplitN(field.Tag.Get("deprecated"), ";", 2)
+		tags := strings.SplitN(field.Tag.Get("deprecated"), ";", 3)
 		if len(tags) < 1 || tags[0] == "" {
 			return
 		}
-		optionInfo := DeprecationInfo{
+		optionInfo := deprecationInfo{
 			Name:  field.Name,
 			Since: tags[0],
-			Level: c.getDeprecationEscalation(tags[0]),
 		}
 
 		if optionInfo.Level != None {
@@ -115,8 +158,13 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 		}
 
 		if len(tags) > 1 {
-			optionInfo.Notice = tags[1]
+			optionInfo.Notice = tags[len(tags)-1]
+		}
+		if len(tags) > 2 {
+			optionInfo.RemovalIn = tags[1]
 		}
+		optionInfo.determineEscalation(c.VersionMajor, c.VersionMinor)
+
 		// Get the toml field name
 		option := field.Tag.Get("toml")
 		if option != "" {
@@ -134,12 +182,12 @@ func (c *Config) printUserDeprecation(category, name string, plugin interface{})
 	switch info.Level {
 	case Warn:
 		prefix := "W! " + color.YellowString("DeprecationWarning")
-		printPluginDeprecationNotice(prefix, info.Name, info.Since, info.Notice)
+		info.printPluginDeprecationNotice(prefix)
 		// We will not check for any deprecated options as the whole plugin is deprecated anyway.
 		return nil
 	case Error:
 		prefix := "E! " + color.RedString("DeprecationError")
-		printPluginDeprecationNotice(prefix, info.Name, info.Since, info.Notice)
+		info.printPluginDeprecationNotice(prefix)
 		// We are past the grace period
 		return fmt.Errorf("plugin deprecated")
 	}
@@ -150,10 +198,10 @@ func (c *Config) printUserDeprecation(category, name string, plugin interface{})
 		switch option.Level {
 		case Warn:
 			prefix := "W! " + color.YellowString("DeprecationWarning")
-			printOptionDeprecationNotice(prefix, info.Name, option.Name, option.Since, option.Notice)
+			option.printOptionDeprecationNotice(prefix, info.Name)
 		case Error:
 			prefix := "E! " + color.RedString("DeprecationError")
-			printOptionDeprecationNotice(prefix, info.Name, option.Name, option.Since, option.Notice)
+			option.printOptionDeprecationNotice(prefix, info.Name)
 			deprecatedOptions = append(deprecatedOptions, option.Name)
 		}
 	}
@@ -165,10 +213,10 @@ func (c *Config) printUserDeprecation(category, name string, plugin interface{})
 	return nil
 }
 
-func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFilter []string) map[string][]PluginDeprecationInfo {
-	infos := make(map[string][]PluginDeprecationInfo)
+func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFilter []string) map[string][]pluginDeprecationInfo {
+	infos := make(map[string][]pluginDeprecationInfo)
 
-	infos["inputs"] = make([]PluginDeprecationInfo, 0)
+	infos["inputs"] = make([]pluginDeprecationInfo, 0)
 	for name, creator := range inputs.Inputs {
 		if len(inFilter) > 0 && !sliceContains(name, inFilter) {
 			continue
@@ -182,7 +230,7 @@ func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFil
 		}
 	}
 
-	infos["outputs"] = make([]PluginDeprecationInfo, 0)
+	infos["outputs"] = make([]pluginDeprecationInfo, 0)
 	for name, creator := range outputs.Outputs {
 		if len(outFilter) > 0 && !sliceContains(name, outFilter) {
 			continue
@@ -196,7 +244,7 @@ func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFil
 		}
 	}
 
-	infos["processors"] = make([]PluginDeprecationInfo, 0)
+	infos["processors"] = make([]pluginDeprecationInfo, 0)
 	for name, creator := range processors.Processors {
 		if len(procFilter) > 0 && !sliceContains(name, procFilter) {
 			continue
@@ -210,7 +258,7 @@ func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFil
 		}
 	}
 
-	infos["aggregators"] = make([]PluginDeprecationInfo, 0)
+	infos["aggregators"] = make([]pluginDeprecationInfo, 0)
 	for name, creator := range aggregators.Aggregators {
 		if len(aggFilter) > 0 && !sliceContains(name, aggFilter) {
 			continue
@@ -227,7 +275,7 @@ func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFil
 	return infos
 }
 
-func (c *Config) PrintDeprecationList(infos []PluginDeprecationInfo) {
+func (c *Config) PrintDeprecationList(infos []pluginDeprecationInfo) {
 	sort.Slice(infos, func(i, j int) bool { return infos[i].Name < infos[j].Name })
 
 	for _, info := range infos {
@@ -246,36 +294,6 @@ func (c *Config) PrintDeprecationList(infos []PluginDeprecationInfo) {
 	}
 }
 
-func (c *Config) getDeprecationEscalation(since string) Escalation {
-	sinceMajor, sinceMinor := ParseVersion(since)
-	if c.VersionMajor > sinceMajor {
-		return Error
-	}
-	if c.VersionMajor == sinceMajor && c.VersionMinor >= sinceMinor {
-		return Warn
-	}
-
-	return None
-}
-
-func printPluginDeprecationNotice(prefix, name, since, notice string) {
-	if notice != "" {
-		log.Printf("%s: Plugin %q deprecated since version %s: %s", prefix, name, since, notice)
-	} else {
-		log.Printf("%s: Plugin %q deprecated since version %s", prefix, name, since)
-	}
-	log.Printf("Please note: %s", pluginWarnNotice)
-}
-
-func printOptionDeprecationNotice(prefix, name, option, since, notice string) {
-	if notice != "" {
-		log.Printf("%s: Option %q of plugin %q deprecated since version %s: %s", prefix, option, name, since, notice)
-	} else {
-		log.Printf("%s: Option %q of plugin %q deprecated since version %s", prefix, option, name, since)
-	}
-	log.Printf("Please note: %s", optionWarnNotice)
-}
-
 // walkPluginStruct iterates over the fields of a structure in depth-first search (to cover nested structures)
 // and calls the given function for every visited field.
 func walkPluginStruct(value reflect.Value, fn func(f reflect.StructField, fv reflect.Value)) {
diff --git a/plugin.go b/plugin.go
index 322f721fd66a3..9bd593cb785f7 100644
--- a/plugin.go
+++ b/plugin.go
@@ -27,7 +27,7 @@ type PluginDescriber interface {
 type PluginDeprecator interface {
 	// DeprecationNotice returns the version since when the plugin is deprecated and
 	// (optionally) provides a deprecation notice allowing to suggest replacements etc.
-	DeprecationNotice() (since string, notice string)
+	DeprecationNotice() (since string, removalIn, notice string)
 }
 
 // Logger defines an plugin-related interface for logging.
diff --git a/plugins/inputs/httpjson/httpjson.go b/plugins/inputs/httpjson/httpjson.go
index 4ca87fa46c1d8..1528a32f09b07 100644
--- a/plugins/inputs/httpjson/httpjson.go
+++ b/plugins/inputs/httpjson/httpjson.go
@@ -283,8 +283,8 @@ func (h *HTTPJSON) sendRequest(serverURL string) (string, float64, error) {
 	return string(body), responseTime, err
 }
 
-func (*HTTPJSON) DeprecationNotice() (since, notice string) {
-	return "1.6", "use 'inputs.http' instead"
+func (*HTTPJSON) DeprecationNotice() (since, removalIn, notice string) {
+	return "1.6", "", "use 'inputs.http' instead"
 }
 
 func init() {

From 71575986ad7b4b802564456b6b8a0dbf57ae1e18 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Tue, 9 Nov 2021 19:29:09 +0100
Subject: [PATCH 24/45] Move deprecation info to long-term persistant tables.

---
 config/deprecation.go                         | 99 +++++++++++--------
 plugin.go                                     | 17 ++--
 plugins/inputs/cassandra/cassandra.go         |  4 -
 plugins/inputs/deprecations.go                | 15 +++
 .../http_listener_v2/http_listener_v2.go      |  4 -
 plugins/inputs/httpjson/httpjson.go           |  4 -
 plugins/inputs/jolokia/jolokia.go             |  4 -
 .../kafka_consumer_legacy.go                  |  4 -
 plugins/inputs/logparser/logparser.go         |  4 -
 plugins/inputs/snmp_legacy/snmp_legacy.go     |  4 -
 plugins/inputs/tcp_listener/tcp_listener.go   |  4 -
 plugins/inputs/udp_listener/udp_listener.go   |  4 -
 plugins/outputs/deprecations.go               |  7 ++
 plugins/outputs/riemann_legacy/riemann.go     |  4 -
 14 files changed, 89 insertions(+), 89 deletions(-)
 create mode 100644 plugins/inputs/deprecations.go
 create mode 100644 plugins/outputs/deprecations.go

diff --git a/config/deprecation.go b/config/deprecation.go
index 4d16a34ba182e..94104fa3dc407 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -45,23 +45,23 @@ type deprecationInfo struct {
 	Name string
 	// Level of deprecation
 	Level Escalation
-	// Since which version the plugin or plugin option is deprecated
-	Since string
-	// RemovalIn is an optional field denoting in which version the plugin or plugin option is actually removed
-	RemovalIn string
-	// Notice to the user about alternatives or further information
-	Notice string
+	info  telegraf.DeprecationInfo
 }
 
 func (di *deprecationInfo) determineEscalation(major, minor int) {
 	var removalMajor, removalMinor int
 
-	sinceMajor, sinceMinor := ParseVersion(di.Since)
-	if di.RemovalIn != "" {
-		removalMajor, removalMinor = ParseVersion(di.RemovalIn)
+	di.Level = None
+	if di.info.Since == "" {
+		return
+	}
+
+	sinceMajor, sinceMinor := ParseVersion(di.info.Since)
+	if di.info.RemovalIn != "" {
+		removalMajor, removalMinor = ParseVersion(di.info.RemovalIn)
 	} else {
 		removalMajor, removalMinor = sinceMajor+1, 0
-		di.RemovalIn = fmt.Sprintf("%d.%d", removalMajor, removalMinor)
+		di.info.RemovalIn = fmt.Sprintf("%d.%d", removalMajor, removalMinor)
 	}
 
 	di.Level = None
@@ -73,29 +73,29 @@ func (di *deprecationInfo) determineEscalation(major, minor int) {
 }
 
 func (di *deprecationInfo) printPluginDeprecationNotice(prefix string) {
-	if di.Notice != "" {
+	if di.info.Notice != "" {
 		log.Printf(
 			"%s: Plugin %q deprecated since version %s and will be removed in %s: %s",
-			prefix, di.Name, di.Since, di.RemovalIn, di.Notice,
+			prefix, di.Name, di.info.Since, di.info.RemovalIn, di.info.Notice,
 		)
 	} else {
 		log.Printf(
 			"%s: Plugin %q deprecated since version %s and will be removed in %s",
-			prefix, di.Name, di.Since, di.RemovalIn,
+			prefix, di.Name, di.info.Since, di.info.RemovalIn,
 		)
 	}
 }
 
 func (di *deprecationInfo) printOptionDeprecationNotice(prefix, plugin string) {
-	if di.Notice != "" {
+	if di.info.Notice != "" {
 		log.Printf(
 			"%s: Option %q of plugin %q deprecated since version %s and will be removed in %s: %s",
-			prefix, di.Name, plugin, di.Since, di.RemovalIn, di.Notice,
+			prefix, di.Name, plugin, di.info.Since, di.info.RemovalIn, di.info.Notice,
 		)
 	} else {
 		log.Printf(
 			"%s: Option %q of plugin %q deprecated since version %s and will be removed in %s",
-			prefix, di.Name, plugin, di.Since, di.RemovalIn,
+			prefix, di.Name, plugin, di.info.Since, di.info.RemovalIn,
 		)
 	}
 }
@@ -125,17 +125,28 @@ func (c *Config) incrementPluginOptionDeprecations(category string) {
 }
 
 func (c *Config) collectDeprecationInfo(category, name string, plugin interface{}, all bool) pluginDeprecationInfo {
-	info := pluginDeprecationInfo{}
-	info.Name = category + "." + name
+	info := pluginDeprecationInfo{
+		deprecationInfo: deprecationInfo{
+			Name:  category + "." + name,
+			Level: None,
+		},
+	}
 
 	// First check if the whole plugin is deprecated
-	if deprecatedPlugin, ok := plugin.(telegraf.PluginDeprecator); ok {
-		info.Since, info.RemovalIn, info.Notice = deprecatedPlugin.DeprecationNotice()
-		info.determineEscalation(c.VersionMajor, c.VersionMinor)
-		if info.Level != None {
-			c.incrementPluginDeprecations(category)
+	switch category {
+	case "inputs":
+		if pi, deprecated := inputs.Deprecations[name]; deprecated {
+			info.deprecationInfo.info = pi
+		}
+	case "outputs":
+		if pi, deprecated := outputs.Deprecations[name]; deprecated {
+			info.deprecationInfo.info = pi
 		}
 	}
+	info.determineEscalation(c.VersionMajor, c.VersionMinor)
+	if info.Level != None {
+		c.incrementPluginDeprecations(category)
+	}
 
 	// Check for deprecated options
 	walkPluginStruct(reflect.ValueOf(plugin), func(field reflect.StructField, value reflect.Value) {
@@ -148,23 +159,21 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 		if len(tags) < 1 || tags[0] == "" {
 			return
 		}
-		optionInfo := deprecationInfo{
-			Name:  field.Name,
-			Since: tags[0],
-		}
-
-		if optionInfo.Level != None {
-			c.incrementPluginOptionDeprecations(category)
-		}
+		optionInfo := deprecationInfo{Name: field.Name}
+		optionInfo.info.Since = tags[0]
 
 		if len(tags) > 1 {
-			optionInfo.Notice = tags[len(tags)-1]
+			optionInfo.info.Notice = tags[len(tags)-1]
 		}
 		if len(tags) > 2 {
-			optionInfo.RemovalIn = tags[1]
+			optionInfo.info.RemovalIn = tags[1]
 		}
 		optionInfo.determineEscalation(c.VersionMajor, c.VersionMinor)
 
+		if optionInfo.Level != None {
+			c.incrementPluginOptionDeprecations(category)
+		}
+
 		// Get the toml field name
 		option := field.Tag.Get("toml")
 		if option != "" {
@@ -275,21 +284,27 @@ func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFil
 	return infos
 }
 
-func (c *Config) PrintDeprecationList(infos []pluginDeprecationInfo) {
-	sort.Slice(infos, func(i, j int) bool { return infos[i].Name < infos[j].Name })
+func (c *Config) PrintDeprecationList(plugins []pluginDeprecationInfo) {
+	sort.Slice(plugins, func(i, j int) bool { return plugins[i].Name < plugins[j].Name })
 
-	for _, info := range infos {
-		switch info.Level {
+	for _, plugin := range plugins {
+		switch plugin.Level {
 		case Warn, Error:
-			_, _ = fmt.Printf("  %-40s %-5s since %5s %s\n", info.Name, info.Level, info.Since, info.Notice)
+			_, _ = fmt.Printf(
+				"  %-40s %-5s since %-5s removal in %-5s %s\n",
+				plugin.Name, plugin.Level, plugin.info.Since, plugin.info.RemovalIn, plugin.info.Notice,
+			)
 		}
 
-		if len(info.Options) < 1 {
+		if len(plugin.Options) < 1 {
 			continue
 		}
-		sort.Slice(info.Options, func(i, j int) bool { return info.Options[i].Name < info.Options[j].Name })
-		for _, option := range info.Options {
-			_, _ = fmt.Printf("  %-40s %-5s since %5s %s\n", info.Name+"/"+option.Name, option.Level, option.Since, option.Notice)
+		sort.Slice(plugin.Options, func(i, j int) bool { return plugin.Options[i].Name < plugin.Options[j].Name })
+		for _, option := range plugin.Options {
+			_, _ = fmt.Printf(
+				"  %-40s %-5s since %-5s removal in %-5s %s\n",
+				plugin.Name+"/"+option.Name, option.Level, option.info.Since, option.info.RemovalIn, option.info.Notice,
+			)
 		}
 	}
 }
diff --git a/plugin.go b/plugin.go
index 9bd593cb785f7..3f4004d766457 100644
--- a/plugin.go
+++ b/plugin.go
@@ -2,6 +2,16 @@ package telegraf
 
 var Debug bool
 
+// DeprecationInfo contains information for marking a plugin deprecated.
+type DeprecationInfo struct {
+	// Since specifies the version since when the plugin is deprecated
+	Since string
+	// RemovalIn optionally specifies the version when the plugin is scheduled for removal
+	RemovalIn string
+	// Notice for the user on suggested replacements etc.
+	Notice string
+}
+
 // Initializer is an interface that all plugin types: Inputs, Outputs,
 // Processors, and Aggregators can optionally implement to initialize the
 // plugin.
@@ -23,13 +33,6 @@ type PluginDescriber interface {
 	Description() string
 }
 
-// PluginDeprecator marks a plugin as deprecated and provides hints to the user.
-type PluginDeprecator interface {
-	// DeprecationNotice returns the version since when the plugin is deprecated and
-	// (optionally) provides a deprecation notice allowing to suggest replacements etc.
-	DeprecationNotice() (since string, removalIn, notice string)
-}
-
 // Logger defines an plugin-related interface for logging.
 type Logger interface {
 	// Errorf logs an error message, patterned after log.Printf.
diff --git a/plugins/inputs/cassandra/cassandra.go b/plugins/inputs/cassandra/cassandra.go
index 456ec93fa2f86..d1c23caadc68a 100644
--- a/plugins/inputs/cassandra/cassandra.go
+++ b/plugins/inputs/cassandra/cassandra.go
@@ -313,10 +313,6 @@ func (c *Cassandra) Gather(acc telegraf.Accumulator) error {
 	return nil
 }
 
-func (*Cassandra) DeprecationNotice() (since, notice string) {
-	return "1.7", "use 'inputs.jolokia2' with the 'cassandra.conf' example configuration instead"
-}
-
 func init() {
 	inputs.Add("cassandra", func() telegraf.Input {
 		return &Cassandra{jClient: &JolokiaClientImpl{client: &http.Client{}}}
diff --git a/plugins/inputs/deprecations.go b/plugins/inputs/deprecations.go
new file mode 100644
index 0000000000000..edec5fcf13ac1
--- /dev/null
+++ b/plugins/inputs/deprecations.go
@@ -0,0 +1,15 @@
+package inputs
+
+import "github.com/influxdata/telegraf"
+
+var Deprecations = map[string]telegraf.DeprecationInfo{
+	"cassandra":             {"1.7", "", "use 'inputs.jolokia2' with the 'cassandra.conf' example configuration instead"},
+	"http_listener_v2":      {"1.9", "", "has been renamed to 'influxdb_listener', use 'inputs.influxdb_listener' or 'inputs.influxdb_listener_v2' instead"},
+	"httpjson":              {"1.6", "", "use 'inputs.http' instead"},
+	"jolokia":               {"1.5", "", "use 'inputs.jolokia2' instead"},
+	"kafka_consumer_legacy": {"1.20", "", "use 'inputs.kafka_consumer' instead, NOTE: 'kafka_consumer' only supports Kafka v0.8+"},
+	"logparser":             {"1.15", "", "use 'inputs.tail' with 'grok' data format instead"},
+	"snmp_legacy":           {"1.20", "", "use 'inputs.snmp' instead"},
+	"tcp_listener":          {"1.3", "", "use 'inputs.socket_listener' instead"},
+	"udp_listener":          {"1.3", "", "use 'inputs.socket_listener' instead"},
+}
diff --git a/plugins/inputs/http_listener_v2/http_listener_v2.go b/plugins/inputs/http_listener_v2/http_listener_v2.go
index 92a7670098a59..d2a2e5f35214e 100644
--- a/plugins/inputs/http_listener_v2/http_listener_v2.go
+++ b/plugins/inputs/http_listener_v2/http_listener_v2.go
@@ -385,10 +385,6 @@ func (h *HTTPListenerV2) authenticateIfSet(handler http.HandlerFunc, res http.Re
 	}
 }
 
-func (*HTTPListenerV2) DeprecationNotice() (since, notice string) {
-	return "1.9", "has been renamed to 'influxdb_listener', use 'inputs.influxdb_listener' or 'inputs.influxdb_listener_v2' instead"
-}
-
 func init() {
 	inputs.Add("http_listener_v2", func() telegraf.Input {
 		return &HTTPListenerV2{
diff --git a/plugins/inputs/httpjson/httpjson.go b/plugins/inputs/httpjson/httpjson.go
index 1528a32f09b07..10a4cb0c17643 100644
--- a/plugins/inputs/httpjson/httpjson.go
+++ b/plugins/inputs/httpjson/httpjson.go
@@ -283,10 +283,6 @@ func (h *HTTPJSON) sendRequest(serverURL string) (string, float64, error) {
 	return string(body), responseTime, err
 }
 
-func (*HTTPJSON) DeprecationNotice() (since, removalIn, notice string) {
-	return "1.6", "", "use 'inputs.http' instead"
-}
-
 func init() {
 	inputs.Add("httpjson", func() telegraf.Input {
 		return &HTTPJSON{
diff --git a/plugins/inputs/jolokia/jolokia.go b/plugins/inputs/jolokia/jolokia.go
index 97f4afcadf503..af5e3de283800 100644
--- a/plugins/inputs/jolokia/jolokia.go
+++ b/plugins/inputs/jolokia/jolokia.go
@@ -318,10 +318,6 @@ func (j *Jolokia) Gather(acc telegraf.Accumulator) error {
 	return nil
 }
 
-func (*Jolokia) DeprecationNotice() (since, notice string) {
-	return "1.5", "use 'inputs.jolokia2' instead"
-}
-
 func init() {
 	inputs.Add("jolokia", func() telegraf.Input {
 		return &Jolokia{
diff --git a/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go b/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go
index 041bf2783d25f..ab19e0875820a 100644
--- a/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go
+++ b/plugins/inputs/kafka_consumer_legacy/kafka_consumer_legacy.go
@@ -184,10 +184,6 @@ func (k *Kafka) Gather(_ telegraf.Accumulator) error {
 	return nil
 }
 
-func (*Kafka) DeprecationNotice() (since, notice string) {
-	return "1.20", "use 'inputs.kafka_consumer' instead, NOTE: 'kafka_consumer' only supports Kafka v0.8+"
-}
-
 func init() {
 	inputs.Add("kafka_consumer_legacy", func() telegraf.Input {
 		return &Kafka{}
diff --git a/plugins/inputs/logparser/logparser.go b/plugins/inputs/logparser/logparser.go
index 486acb957cdab..83f5abd210bdd 100644
--- a/plugins/inputs/logparser/logparser.go
+++ b/plugins/inputs/logparser/logparser.go
@@ -360,10 +360,6 @@ func (l *LogParserPlugin) Stop() {
 	offsetsMutex.Unlock()
 }
 
-func (*LogParserPlugin) DeprecationNotice() (since, notice string) {
-	return "1.15", "use 'inputs.tail' with 'grok' data format instead"
-}
-
 func init() {
 	inputs.Add("logparser", func() telegraf.Input {
 		return NewLogParser()
diff --git a/plugins/inputs/snmp_legacy/snmp_legacy.go b/plugins/inputs/snmp_legacy/snmp_legacy.go
index 2ee19768a65b9..ce454cbfbad36 100644
--- a/plugins/inputs/snmp_legacy/snmp_legacy.go
+++ b/plugins/inputs/snmp_legacy/snmp_legacy.go
@@ -815,10 +815,6 @@ func (h *Host) HandleResponse(
 	return lastOid, nil
 }
 
-func (*Snmp) DeprecationNotice() (since, notice string) {
-	return "1.20", "use 'inputs.snmp' instead"
-}
-
 func init() {
 	inputs.Add("snmp_legacy", func() telegraf.Input {
 		return &Snmp{}
diff --git a/plugins/inputs/tcp_listener/tcp_listener.go b/plugins/inputs/tcp_listener/tcp_listener.go
index 499f57a7be913..8eeaa9cff8091 100644
--- a/plugins/inputs/tcp_listener/tcp_listener.go
+++ b/plugins/inputs/tcp_listener/tcp_listener.go
@@ -297,10 +297,6 @@ func (t *TCPListener) remember(id string, conn *net.TCPConn) {
 	t.conns[id] = conn
 }
 
-func (*TCPListener) DeprecationNotice() (since, notice string) {
-	return "1.3", "use 'inputs.socket_listener' instead"
-}
-
 func init() {
 	inputs.Add("tcp_listener", func() telegraf.Input {
 		return &TCPListener{
diff --git a/plugins/inputs/udp_listener/udp_listener.go b/plugins/inputs/udp_listener/udp_listener.go
index d9eda53955399..39fef79ce1b98 100644
--- a/plugins/inputs/udp_listener/udp_listener.go
+++ b/plugins/inputs/udp_listener/udp_listener.go
@@ -221,10 +221,6 @@ func (u *UDPListener) udpParser() {
 	}
 }
 
-func (*UDPListener) DeprecationNotice() (since, notice string) {
-	return "1.3", "use 'inputs.socket_listener' instead"
-}
-
 func init() {
 	inputs.Add("udp_listener", func() telegraf.Input {
 		return &UDPListener{
diff --git a/plugins/outputs/deprecations.go b/plugins/outputs/deprecations.go
new file mode 100644
index 0000000000000..900e5ffd1e36b
--- /dev/null
+++ b/plugins/outputs/deprecations.go
@@ -0,0 +1,7 @@
+package outputs
+
+import "github.com/influxdata/telegraf"
+
+var Deprecations = map[string]telegraf.DeprecationInfo{
+	"riemann_legacy": {"1.20", "", "use 'outputs.riemann' instead (see https://github.com/influxdata/telegraf/issues/1878)"},
+}
diff --git a/plugins/outputs/riemann_legacy/riemann.go b/plugins/outputs/riemann_legacy/riemann.go
index ff03feac63410..0bd0f6b876c68 100644
--- a/plugins/outputs/riemann_legacy/riemann.go
+++ b/plugins/outputs/riemann_legacy/riemann.go
@@ -147,10 +147,6 @@ func serviceName(s string, n string, t map[string]string, f string) string {
 	return strings.Join(serviceStrings, s)
 }
 
-func (*Riemann) DeprecationNotice() (since, notice string) {
-	return "1.20", "use 'outputs.riemann' instead (see https://github.com/influxdata/telegraf/issues/1878)"
-}
-
 func init() {
 	outputs.Add("riemann_legacy", func() telegraf.Output {
 		return &Riemann{}

From 3374eae1632afff7646ac4ea8769e3dc3cbc3c38 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Tue, 9 Nov 2021 19:56:40 +0100
Subject: [PATCH 25/45] Print deprecation notice for deprecated and already
 removed plugins.

---
 config/config.go                    | 22 +++++++++++
 config/deprecation.go               | 58 +++++++++++++----------------
 plugins/aggregators/deprecations.go |  5 +++
 plugins/processors/deprecations.go  |  5 +++
 4 files changed, 58 insertions(+), 32 deletions(-)
 create mode 100644 plugins/aggregators/deprecations.go
 create mode 100644 plugins/processors/deprecations.go

diff --git a/config/config.go b/config/config.go
index affba30b2ae38..7e2cb836adf3f 100644
--- a/config/config.go
+++ b/config/config.go
@@ -1014,6 +1014,11 @@ func parseConfig(contents []byte) (*ast.Table, error) {
 func (c *Config) addAggregator(name string, table *ast.Table) error {
 	creator, ok := aggregators.Aggregators[name]
 	if !ok {
+		// Handle removed, deprecated plugins
+		if di, deprecated := aggregators.Deprecations[name]; deprecated {
+			printHistoricPluginDeprecationNotice("aggregators", name, di)
+			return fmt.Errorf("plugin deprecated")
+		}
 		return fmt.Errorf("Undefined but requested aggregator: %s", name)
 	}
 	aggregator := creator()
@@ -1038,6 +1043,11 @@ func (c *Config) addAggregator(name string, table *ast.Table) error {
 func (c *Config) addProcessor(name string, table *ast.Table) error {
 	creator, ok := processors.Processors[name]
 	if !ok {
+		// Handle removed, deprecated plugins
+		if di, deprecated := processors.Deprecations[name]; deprecated {
+			printHistoricPluginDeprecationNotice("processors", name, di)
+			return fmt.Errorf("plugin deprecated")
+		}
 		return fmt.Errorf("Undefined but requested processor: %s", name)
 	}
 
@@ -1093,6 +1103,11 @@ func (c *Config) addOutput(name string, table *ast.Table) error {
 	}
 	creator, ok := outputs.Outputs[name]
 	if !ok {
+		// Handle removed, deprecated plugins
+		if di, deprecated := outputs.Deprecations[name]; deprecated {
+			printHistoricPluginDeprecationNotice("outputs", name, di)
+			return fmt.Errorf("plugin deprecated")
+		}
 		return fmt.Errorf("Undefined but requested output: %s", name)
 	}
 	output := creator()
@@ -1130,6 +1145,7 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 	if len(c.InputFilters) > 0 && !sliceContains(name, c.InputFilters) {
 		return nil
 	}
+
 	// Legacy support renaming io input to diskio
 	if name == "io" {
 		name = "diskio"
@@ -1137,6 +1153,12 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 
 	creator, ok := inputs.Inputs[name]
 	if !ok {
+		// Handle removed, deprecated plugins
+		if di, deprecated := inputs.Deprecations[name]; deprecated {
+			printHistoricPluginDeprecationNotice("inputs", name, di)
+			return fmt.Errorf("plugin deprecated")
+		}
+
 		return fmt.Errorf("Undefined but requested input: %s", name)
 	}
 	input := creator()
diff --git a/config/deprecation.go b/config/deprecation.go
index 94104fa3dc407..8dc691d63de2f 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -72,34 +72,6 @@ func (di *deprecationInfo) determineEscalation(major, minor int) {
 	}
 }
 
-func (di *deprecationInfo) printPluginDeprecationNotice(prefix string) {
-	if di.info.Notice != "" {
-		log.Printf(
-			"%s: Plugin %q deprecated since version %s and will be removed in %s: %s",
-			prefix, di.Name, di.info.Since, di.info.RemovalIn, di.info.Notice,
-		)
-	} else {
-		log.Printf(
-			"%s: Plugin %q deprecated since version %s and will be removed in %s",
-			prefix, di.Name, di.info.Since, di.info.RemovalIn,
-		)
-	}
-}
-
-func (di *deprecationInfo) printOptionDeprecationNotice(prefix, plugin string) {
-	if di.info.Notice != "" {
-		log.Printf(
-			"%s: Option %q of plugin %q deprecated since version %s and will be removed in %s: %s",
-			prefix, di.Name, plugin, di.info.Since, di.info.RemovalIn, di.info.Notice,
-		)
-	} else {
-		log.Printf(
-			"%s: Option %q of plugin %q deprecated since version %s and will be removed in %s",
-			prefix, di.Name, plugin, di.info.Since, di.info.RemovalIn,
-		)
-	}
-}
-
 // pluginDeprecationInfo holds all information about a deprecated plugin or it's options
 type pluginDeprecationInfo struct {
 	deprecationInfo
@@ -191,12 +163,12 @@ func (c *Config) printUserDeprecation(category, name string, plugin interface{})
 	switch info.Level {
 	case Warn:
 		prefix := "W! " + color.YellowString("DeprecationWarning")
-		info.printPluginDeprecationNotice(prefix)
+		printPluginDeprecationNotice(prefix, info.Name, info.info)
 		// We will not check for any deprecated options as the whole plugin is deprecated anyway.
 		return nil
 	case Error:
 		prefix := "E! " + color.RedString("DeprecationError")
-		info.printPluginDeprecationNotice(prefix)
+		printPluginDeprecationNotice(prefix, info.Name, info.info)
 		// We are past the grace period
 		return fmt.Errorf("plugin deprecated")
 	}
@@ -207,10 +179,10 @@ func (c *Config) printUserDeprecation(category, name string, plugin interface{})
 		switch option.Level {
 		case Warn:
 			prefix := "W! " + color.YellowString("DeprecationWarning")
-			option.printOptionDeprecationNotice(prefix, info.Name)
+			printOptionDeprecationNotice(prefix, info.Name, option.Name, option.info)
 		case Error:
 			prefix := "E! " + color.RedString("DeprecationError")
-			option.printOptionDeprecationNotice(prefix, info.Name)
+			printOptionDeprecationNotice(prefix, info.Name, option.Name, option.info)
 			deprecatedOptions = append(deprecatedOptions, option.Name)
 		}
 	}
@@ -309,6 +281,28 @@ func (c *Config) PrintDeprecationList(plugins []pluginDeprecationInfo) {
 	}
 }
 
+func printHistoricPluginDeprecationNotice(category, name string, info telegraf.DeprecationInfo) {
+	prefix := "E! " + color.RedString("DeprecationError")
+	log.Printf(
+		"%s: Plugin %q deprecated since version %s and removed: %s",
+		prefix, category+"."+name, info.Since, info.Notice,
+	)
+}
+
+func printPluginDeprecationNotice(prefix, name string, info telegraf.DeprecationInfo) {
+	log.Printf(
+		"%s: Plugin %q deprecated since version %s and will be removed in %s: %s",
+		prefix, name, info.Since, info.RemovalIn, info.Notice,
+	)
+}
+
+func printOptionDeprecationNotice(prefix, plugin, option string, info telegraf.DeprecationInfo) {
+	log.Printf(
+		"%s: Option %q of plugin %q deprecated since version %s and will be removed in %s: %s",
+		prefix, option, plugin, info.Since, info.RemovalIn, info.Notice,
+	)
+}
+
 // walkPluginStruct iterates over the fields of a structure in depth-first search (to cover nested structures)
 // and calls the given function for every visited field.
 func walkPluginStruct(value reflect.Value, fn func(f reflect.StructField, fv reflect.Value)) {
diff --git a/plugins/aggregators/deprecations.go b/plugins/aggregators/deprecations.go
new file mode 100644
index 0000000000000..8acf5305045a0
--- /dev/null
+++ b/plugins/aggregators/deprecations.go
@@ -0,0 +1,5 @@
+package aggregators
+
+import "github.com/influxdata/telegraf"
+
+var Deprecations = map[string]telegraf.DeprecationInfo{}
diff --git a/plugins/processors/deprecations.go b/plugins/processors/deprecations.go
new file mode 100644
index 0000000000000..365e829045ab8
--- /dev/null
+++ b/plugins/processors/deprecations.go
@@ -0,0 +1,5 @@
+package processors
+
+import "github.com/influxdata/telegraf"
+
+var Deprecations = map[string]telegraf.DeprecationInfo{}

From ef8bfcbc518a4f7d984d717e562375c767ab3a5c Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Tue, 9 Nov 2021 20:04:55 +0100
Subject: [PATCH 26/45] Use keyed fields.

---
 plugins/inputs/deprecations.go  | 45 ++++++++++++++++++++++++++-------
 plugins/outputs/deprecations.go |  5 +++-
 2 files changed, 40 insertions(+), 10 deletions(-)

diff --git a/plugins/inputs/deprecations.go b/plugins/inputs/deprecations.go
index edec5fcf13ac1..3aaddc7f9ef31 100644
--- a/plugins/inputs/deprecations.go
+++ b/plugins/inputs/deprecations.go
@@ -3,13 +3,40 @@ package inputs
 import "github.com/influxdata/telegraf"
 
 var Deprecations = map[string]telegraf.DeprecationInfo{
-	"cassandra":             {"1.7", "", "use 'inputs.jolokia2' with the 'cassandra.conf' example configuration instead"},
-	"http_listener_v2":      {"1.9", "", "has been renamed to 'influxdb_listener', use 'inputs.influxdb_listener' or 'inputs.influxdb_listener_v2' instead"},
-	"httpjson":              {"1.6", "", "use 'inputs.http' instead"},
-	"jolokia":               {"1.5", "", "use 'inputs.jolokia2' instead"},
-	"kafka_consumer_legacy": {"1.20", "", "use 'inputs.kafka_consumer' instead, NOTE: 'kafka_consumer' only supports Kafka v0.8+"},
-	"logparser":             {"1.15", "", "use 'inputs.tail' with 'grok' data format instead"},
-	"snmp_legacy":           {"1.20", "", "use 'inputs.snmp' instead"},
-	"tcp_listener":          {"1.3", "", "use 'inputs.socket_listener' instead"},
-	"udp_listener":          {"1.3", "", "use 'inputs.socket_listener' instead"},
+	"cassandra": {
+		Since:  "1.7",
+		Notice: "use 'inputs.jolokia2' with the 'cassandra.conf' example configuration instead",
+	},
+	"http_listener_v2": {
+		Since:  "1.9",
+		Notice: "has been renamed to 'influxdb_listener', use 'inputs.influxdb_listener' or 'inputs.influxdb_listener_v2' instead",
+	},
+	"httpjson": {
+		Since:  "1.6",
+		Notice: "use 'inputs.http' instead",
+	},
+	"jolokia": {
+		Since:  "1.5",
+		Notice: "use 'inputs.jolokia2' instead",
+	},
+	"kafka_consumer_legacy": {
+		Since:  "1.20",
+		Notice: "use 'inputs.kafka_consumer' instead, NOTE: 'kafka_consumer' only supports Kafka v0.8+",
+	},
+	"logparser": {
+		Since:  "1.15",
+		Notice: "use 'inputs.tail' with 'grok' data format instead",
+	},
+	"snmp_legacy": {
+		Since:  "1.20",
+		Notice: "use 'inputs.snmp' instead",
+	},
+	"tcp_listener": {
+		Since:  "1.3",
+		Notice: "use 'inputs.socket_listener' instead",
+	},
+	"udp_listener": {
+		Since:  "1.3",
+		Notice: "use 'inputs.socket_listener' instead",
+	},
 }
diff --git a/plugins/outputs/deprecations.go b/plugins/outputs/deprecations.go
index 900e5ffd1e36b..de09f51fedabc 100644
--- a/plugins/outputs/deprecations.go
+++ b/plugins/outputs/deprecations.go
@@ -3,5 +3,8 @@ package outputs
 import "github.com/influxdata/telegraf"
 
 var Deprecations = map[string]telegraf.DeprecationInfo{
-	"riemann_legacy": {"1.20", "", "use 'outputs.riemann' instead (see https://github.com/influxdata/telegraf/issues/1878)"},
+	"riemann_legacy": {
+		Since:  "1.20",
+		Notice: "use 'outputs.riemann' instead (see https://github.com/influxdata/telegraf/issues/1878)",
+	},
 }

From aa5039dd63343d7af84829249754026144b9f747 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 10:19:38 +0100
Subject: [PATCH 27/45] Allow <br> HTML elements for Markdown as they are often
 the only why to enforce a linebreak.

---
 .markdownlint.yml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/.markdownlint.yml b/.markdownlint.yml
index 1344b312f825e..893179487d310 100644
--- a/.markdownlint.yml
+++ b/.markdownlint.yml
@@ -1,3 +1,6 @@
 {
-    "MD013": false
+    "MD013": false,
+    "MD033": {
+      "allowed_elements": ["br"]
+    }
 }

From 64e876aca54a8c075989c27312f72c25850f8a83 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 10:32:01 +0100
Subject: [PATCH 28/45] Add inputs.io to list of deprecated plugins.

---
 config/config.go               | 3 +++
 config/deprecation.go          | 5 +++++
 plugins/inputs/deprecations.go | 4 ++++
 3 files changed, 12 insertions(+)

diff --git a/config/config.go b/config/config.go
index 7e2cb836adf3f..35e4b4624e131 100644
--- a/config/config.go
+++ b/config/config.go
@@ -1148,6 +1148,9 @@ func (c *Config) addInput(name string, table *ast.Table) error {
 
 	// Legacy support renaming io input to diskio
 	if name == "io" {
+		if err := c.printUserDeprecation("inputs", name, nil); err != nil {
+			return err
+		}
 		name = "diskio"
 	}
 
diff --git a/config/deprecation.go b/config/deprecation.go
index 8dc691d63de2f..ca1d2d71c8dda 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -120,6 +120,11 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 		c.incrementPluginDeprecations(category)
 	}
 
+	// Allow checking for names only.
+	if plugin == nil {
+		return info
+	}
+
 	// Check for deprecated options
 	walkPluginStruct(reflect.ValueOf(plugin), func(field reflect.StructField, value reflect.Value) {
 		// Try to report only those fields that are set
diff --git a/plugins/inputs/deprecations.go b/plugins/inputs/deprecations.go
index 3aaddc7f9ef31..b8b4adfc55fef 100644
--- a/plugins/inputs/deprecations.go
+++ b/plugins/inputs/deprecations.go
@@ -7,6 +7,10 @@ var Deprecations = map[string]telegraf.DeprecationInfo{
 		Since:  "1.7",
 		Notice: "use 'inputs.jolokia2' with the 'cassandra.conf' example configuration instead",
 	},
+	"io": {
+		Since:  "1.20",
+		Notice: "use 'inputs.diskio' instead",
+	},
 	"http_listener_v2": {
 		Since:  "1.9",
 		Notice: "has been renamed to 'influxdb_listener', use 'inputs.influxdb_listener' or 'inputs.influxdb_listener_v2' instead",

From d51cf51abb8f81c6dfbe02b07d251ea0470ba1c9 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 10:36:21 +0100
Subject: [PATCH 29/45] Remove color from deprecation output.

---
 config/deprecation.go | 12 +++++-------
 go.mod                |  2 +-
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index ca1d2d71c8dda..4e9f17b6b31e6 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -8,8 +8,6 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/fatih/color"
-
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/aggregators"
 	"github.com/influxdata/telegraf/plugins/inputs"
@@ -167,12 +165,12 @@ func (c *Config) printUserDeprecation(category, name string, plugin interface{})
 
 	switch info.Level {
 	case Warn:
-		prefix := "W! " + color.YellowString("DeprecationWarning")
+		prefix := "W! DeprecationWarning"
 		printPluginDeprecationNotice(prefix, info.Name, info.info)
 		// We will not check for any deprecated options as the whole plugin is deprecated anyway.
 		return nil
 	case Error:
-		prefix := "E! " + color.RedString("DeprecationError")
+		prefix := "E! DeprecationError"
 		printPluginDeprecationNotice(prefix, info.Name, info.info)
 		// We are past the grace period
 		return fmt.Errorf("plugin deprecated")
@@ -183,10 +181,10 @@ func (c *Config) printUserDeprecation(category, name string, plugin interface{})
 	for _, option := range info.Options {
 		switch option.Level {
 		case Warn:
-			prefix := "W! " + color.YellowString("DeprecationWarning")
+			prefix := "W! DeprecationWarning"
 			printOptionDeprecationNotice(prefix, info.Name, option.Name, option.info)
 		case Error:
-			prefix := "E! " + color.RedString("DeprecationError")
+			prefix := "E! DeprecationError"
 			printOptionDeprecationNotice(prefix, info.Name, option.Name, option.info)
 			deprecatedOptions = append(deprecatedOptions, option.Name)
 		}
@@ -287,7 +285,7 @@ func (c *Config) PrintDeprecationList(plugins []pluginDeprecationInfo) {
 }
 
 func printHistoricPluginDeprecationNotice(category, name string, info telegraf.DeprecationInfo) {
-	prefix := "E! " + color.RedString("DeprecationError")
+	prefix := "E! DeprecationError"
 	log.Printf(
 		"%s: Plugin %q deprecated since version %s and removed: %s",
 		prefix, category+"."+name, info.Since, info.Notice,
diff --git a/go.mod b/go.mod
index b12d45dbb1ab2..75496c6646c71 100644
--- a/go.mod
+++ b/go.mod
@@ -98,7 +98,7 @@ require (
 	github.com/eapache/queue v1.1.0 // indirect
 	github.com/echlebek/timeproxy v1.0.0 // indirect
 	github.com/eclipse/paho.mqtt.golang v1.3.0
-	github.com/fatih/color v1.10.0
+	github.com/fatih/color v1.10.0 // indirect
 	github.com/form3tech-oss/jwt-go v3.2.5+incompatible // indirect
 	github.com/ghodss/yaml v1.0.1-0.20190212211648-25d852aebe32
 	github.com/go-logfmt/logfmt v0.5.0

From 56ce5b02351b991a30510ac7952047616b58d530 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 10:41:43 +0100
Subject: [PATCH 30/45] Fix Makefile.

---
 Makefile | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/Makefile b/Makefile
index 2b5864602564a..0e4b21bcb4b3d 100644
--- a/Makefile
+++ b/Makefile
@@ -150,19 +150,18 @@ lint-install:
 
 .PHONY: lint
 lint:
-	@which golangci-lint >/dev/null 2>&1 || { \
-		echo "golangci-lint not found, please run: make lint-install"; \
-		exit 1; \
-	}
-
-	golangci-lint run
-
-	@which markdownlint >/dev/null 2>&1 || { \
-		echo "markdownlint not found, please run: make lint-install"; \
-		exit 1; \
-	}
-
-	markdownlint .
+	ifeq (, $(shell which golangci-lint))
+		$(info golangci-lint can't be found, please run: make lint-install)
+		exit 1
+	endif
+
+		golangci-lint run
+
+	ifeq (, $(shell which markdownlint-cli))
+		$(info markdownlint-cli can't be found, please run: make lint-install)
+		exit 1
+	endif
+	markdownlint-cli
 
 .PHONY: lint-branch
 lint-branch:

From 805cd32d6ebdde4addebc1fd0c6a5b4572d81231 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 11:04:42 +0100
Subject: [PATCH 31/45] Use go-semver for versioning.

---
 cmd/telegraf/telegraf.go |  4 +--
 config/config.go         | 10 ++++++--
 config/deprecation.go    | 54 ++++++++++++++++------------------------
 go.mod                   |  2 +-
 4 files changed, 33 insertions(+), 37 deletions(-)

diff --git a/cmd/telegraf/telegraf.go b/cmd/telegraf/telegraf.go
index 4dd2b5a1c19f0..cdac666d49519 100644
--- a/cmd/telegraf/telegraf.go
+++ b/cmd/telegraf/telegraf.go
@@ -197,7 +197,7 @@ func runAgent(ctx context.Context,
 
 	// If no other options are specified, load the config file and run.
 	c := config.NewConfig()
-	c.VersionMajor, c.VersionMinor = config.ParseVersion(version)
+	c.SetVersion(version)
 	c.OutputFilters = outputFilters
 	c.InputFilters = inputFilters
 	var err error
@@ -410,7 +410,7 @@ func main() {
 	switch {
 	case *fDeprecationList:
 		c := config.NewConfig()
-		c.VersionMajor, c.VersionMinor = config.ParseVersion(version)
+		c.SetVersion(version)
 		infos := c.CollectDeprecationInfos(
 			inputFilters,
 			outputFilters,
diff --git a/config/config.go b/config/config.go
index 35e4b4624e131..f8f47e7b85b4c 100644
--- a/config/config.go
+++ b/config/config.go
@@ -17,6 +17,8 @@ import (
 	"strings"
 	"time"
 
+	"github.com/coreos/go-semver/semver"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/telegraf/internal/choice"
@@ -78,8 +80,7 @@ type Config struct {
 	Processors    models.RunningProcessors
 	AggProcessors models.RunningProcessors
 
-	VersionMajor int
-	VersionMinor int
+	Version      *semver.Version
 	Deprecations map[string][]int64
 }
 
@@ -207,6 +208,11 @@ type AgentConfig struct {
 	OmitHostname bool
 }
 
+// SetVersion stores the telegraf version
+func (c *Config) SetVersion(version string) {
+	c.Version = semver.New(version)
+}
+
 // InputNames returns a list of strings of the configured inputs.
 func (c *Config) InputNames() []string {
 	var name []string
diff --git a/config/deprecation.go b/config/deprecation.go
index 4e9f17b6b31e6..f38a781a730a7 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -5,9 +5,10 @@ import (
 	"log" //nolint:revive // log is ok here as the logging facility is not set-up yet
 	"reflect"
 	"sort"
-	"strconv"
 	"strings"
 
+	"github.com/coreos/go-semver/semver"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/aggregators"
 	"github.com/influxdata/telegraf/plugins/inputs"
@@ -46,28 +47,35 @@ type deprecationInfo struct {
 	info  telegraf.DeprecationInfo
 }
 
-func (di *deprecationInfo) determineEscalation(major, minor int) {
-	var removalMajor, removalMinor int
-
+func (di *deprecationInfo) determineEscalation(version *semver.Version) error {
 	di.Level = None
 	if di.info.Since == "" {
-		return
+		return nil
+	}
+
+	since, err := semver.NewVersion(di.info.Since+".0")
+	if err != nil {
+		return fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since+".0", err)
 	}
 
-	sinceMajor, sinceMinor := ParseVersion(di.info.Since)
+	var removal *semver.Version
 	if di.info.RemovalIn != "" {
-		removalMajor, removalMinor = ParseVersion(di.info.RemovalIn)
+		removal, err = semver.NewVersion(di.info.RemovalIn+".0")
+		if err != nil {
+			return fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn+".0", err)
+		}
 	} else {
-		removalMajor, removalMinor = sinceMajor+1, 0
-		di.info.RemovalIn = fmt.Sprintf("%d.%d", removalMajor, removalMinor)
+		removal = &semver.Version{Major: since.Major,	Minor: since.Minor}
+		removal.BumpMajor()
+		di.info.RemovalIn = removal.String()
 	}
 
-	di.Level = None
-	if major > removalMajor || (major == removalMajor && minor >= removalMinor) {
+	if !version.LessThan(*removal) {
 		di.Level = Error
-	} else if major > sinceMajor || (major == sinceMajor && minor >= sinceMinor) {
+	} else if !version.LessThan(*since) {
 		di.Level = Warn
 	}
+	return nil
 }
 
 // pluginDeprecationInfo holds all information about a deprecated plugin or it's options
@@ -113,7 +121,7 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 			info.deprecationInfo.info = pi
 		}
 	}
-	info.determineEscalation(c.VersionMajor, c.VersionMinor)
+	info.determineEscalation(c.Version)
 	if info.Level != None {
 		c.incrementPluginDeprecations(category)
 	}
@@ -143,7 +151,7 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 		if len(tags) > 2 {
 			optionInfo.info.RemovalIn = tags[1]
 		}
-		optionInfo.determineEscalation(c.VersionMajor, c.VersionMinor)
+		optionInfo.determineEscalation(c.Version)
 
 		if optionInfo.Level != None {
 			c.incrementPluginOptionDeprecations(category)
@@ -349,21 +357,3 @@ func walkPluginStruct(value reflect.Value, fn func(f reflect.StructField, fv ref
 		fn(field, fieldValue)
 	}
 }
-
-func ParseVersion(version string) (major, minor int) {
-	parts := strings.SplitN(version, ".", 3)
-	if len(parts) < 2 {
-		panic(fmt.Errorf("insufficient version fields in %q", version))
-	}
-
-	major, err := strconv.Atoi(parts[0])
-	if err != nil {
-		panic(fmt.Errorf("invalid version major in %q", version))
-	}
-
-	minor, err = strconv.Atoi(parts[1])
-	if err != nil {
-		panic(fmt.Errorf("invalid version major in %q", version))
-	}
-	return major, minor
-}
diff --git a/go.mod b/go.mod
index 75496c6646c71..a03a24cb6a87b 100644
--- a/go.mod
+++ b/go.mod
@@ -78,7 +78,7 @@ require (
 	github.com/cisco-ie/nx-telemetry-proto v0.0.0-20190531143454-82441e232cf6
 	github.com/containerd/cgroups v1.0.1 // indirect
 	github.com/containerd/containerd v1.5.7 // indirect
-	github.com/coreos/go-semver v0.3.0 // indirect
+	github.com/coreos/go-semver v0.3.0
 	github.com/couchbase/go-couchbase v0.1.0
 	github.com/couchbase/gomemcached v0.1.3 // indirect
 	github.com/couchbase/goutils v0.1.0 // indirect

From 041cc5dad78595c66846d9627649517d9a8519e1 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 11:25:06 +0100
Subject: [PATCH 32/45] Simplify version handling in telegraf.

---
 cmd/telegraf/telegraf.go | 17 +++++------------
 config/config.go         | 12 +++++++-----
 config/deprecation.go    |  8 ++++----
 internal/internal.go     |  4 ++++
 4 files changed, 20 insertions(+), 21 deletions(-)

diff --git a/cmd/telegraf/telegraf.go b/cmd/telegraf/telegraf.go
index cdac666d49519..66cdd35315301 100644
--- a/cmd/telegraf/telegraf.go
+++ b/cmd/telegraf/telegraf.go
@@ -197,7 +197,6 @@ func runAgent(ctx context.Context,
 
 	// If no other options are specified, load the config file and run.
 	c := config.NewConfig()
-	c.SetVersion(version)
 	c.OutputFilters = outputFilters
 	c.InputFilters = inputFilters
 	var err error
@@ -364,6 +363,11 @@ func main() {
 
 	logger.SetupLogging(logger.LogConfig{})
 
+	// Configure version
+	if err := internal.SetVersion(version); err != nil {
+		log.Println("Telegraf version already configured to: " + internal.Version())
+	}
+
 	// Load external plugins, if requested.
 	if *fPlugins != "" {
 		log.Printf("I! Loading external plugins from: %s", *fPlugins)
@@ -410,7 +414,6 @@ func main() {
 	switch {
 	case *fDeprecationList:
 		c := config.NewConfig()
-		c.SetVersion(version)
 		infos := c.CollectDeprecationInfos(
 			inputFilters,
 			outputFilters,
@@ -473,16 +476,6 @@ func main() {
 		return
 	}
 
-	shortVersion := version
-	if shortVersion == "" {
-		shortVersion = "unknown"
-	}
-
-	// Configure version
-	if err := internal.SetVersion(shortVersion); err != nil {
-		log.Println("Telegraf version already configured to: " + internal.Version())
-	}
-
 	run(
 		inputFilters,
 		outputFilters,
diff --git a/config/config.go b/config/config.go
index f8f47e7b85b4c..f5fcada77f8ee 100644
--- a/config/config.go
+++ b/config/config.go
@@ -110,6 +110,13 @@ func NewConfig() *Config {
 		Deprecations:  make(map[string][]int64),
 	}
 
+	// Handle unknown version
+	version := internal.Version()
+	if version == "" || version == "unknown" {
+		version = "0.0.0-unknown"
+	}
+	c.Version = semver.New(version)
+
 	tomlCfg := &toml.Config{
 		NormFieldName: toml.DefaultConfig.NormFieldName,
 		FieldToKey:    toml.DefaultConfig.FieldToKey,
@@ -208,11 +215,6 @@ type AgentConfig struct {
 	OmitHostname bool
 }
 
-// SetVersion stores the telegraf version
-func (c *Config) SetVersion(version string) {
-	c.Version = semver.New(version)
-}
-
 // InputNames returns a list of strings of the configured inputs.
 func (c *Config) InputNames() []string {
 	var name []string
diff --git a/config/deprecation.go b/config/deprecation.go
index f38a781a730a7..74f5faac2079a 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -53,21 +53,21 @@ func (di *deprecationInfo) determineEscalation(version *semver.Version) error {
 		return nil
 	}
 
-	since, err := semver.NewVersion(di.info.Since+".0")
+	since, err := semver.NewVersion(di.info.Since + ".0")
 	if err != nil {
 		return fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since+".0", err)
 	}
 
 	var removal *semver.Version
 	if di.info.RemovalIn != "" {
-		removal, err = semver.NewVersion(di.info.RemovalIn+".0")
+		removal, err = semver.NewVersion(di.info.RemovalIn + ".0")
 		if err != nil {
 			return fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn+".0", err)
 		}
 	} else {
-		removal = &semver.Version{Major: since.Major,	Minor: since.Minor}
+		removal = &semver.Version{Major: since.Major, Minor: since.Minor}
 		removal.BumpMajor()
-		di.info.RemovalIn = removal.String()
+		di.info.RemovalIn = strings.TrimSuffix(removal.String(), ".0")
 	}
 
 	if !version.LessThan(*removal) {
diff --git a/internal/internal.go b/internal/internal.go
index 4441e9acfbf03..49f92bfcd1265 100644
--- a/internal/internal.go
+++ b/internal/internal.go
@@ -42,6 +42,10 @@ func SetVersion(v string) error {
 		return ErrorVersionAlreadySet
 	}
 	version = v
+	if version == "" {
+		version = "unknown"
+	}
+
 	return nil
 }
 

From 1dcb0d77b1408dc7ee9eaade6aa48729231f7e77 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 11:26:59 +0100
Subject: [PATCH 33/45] Make version internal.

---
 config/config.go      | 4 ++--
 config/deprecation.go | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/config/config.go b/config/config.go
index f5fcada77f8ee..4121c71687e66 100644
--- a/config/config.go
+++ b/config/config.go
@@ -80,8 +80,8 @@ type Config struct {
 	Processors    models.RunningProcessors
 	AggProcessors models.RunningProcessors
 
-	Version      *semver.Version
 	Deprecations map[string][]int64
+	version      *semver.Version
 }
 
 // NewConfig creates a new struct to hold the Telegraf config.
@@ -115,7 +115,7 @@ func NewConfig() *Config {
 	if version == "" || version == "unknown" {
 		version = "0.0.0-unknown"
 	}
-	c.Version = semver.New(version)
+	c.version = semver.New(version)
 
 	tomlCfg := &toml.Config{
 		NormFieldName: toml.DefaultConfig.NormFieldName,
diff --git a/config/deprecation.go b/config/deprecation.go
index 74f5faac2079a..81f824ec74fe1 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -121,7 +121,7 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 			info.deprecationInfo.info = pi
 		}
 	}
-	info.determineEscalation(c.Version)
+	info.determineEscalation(c.version)
 	if info.Level != None {
 		c.incrementPluginDeprecations(category)
 	}
@@ -151,7 +151,7 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 		if len(tags) > 2 {
 			optionInfo.info.RemovalIn = tags[1]
 		}
-		optionInfo.determineEscalation(c.Version)
+		optionInfo.determineEscalation(c.version)
 
 		if optionInfo.Level != None {
 			c.incrementPluginOptionDeprecations(category)

From 2a2115050661033f7a8034bc8d1653efa98e2740 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 11:39:33 +0100
Subject: [PATCH 34/45] Fix linter error.

---
 config/deprecation.go           | 9 ++++-----
 docs/LICENSE_OF_DEPENDENCIES.md | 1 +
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index 81f824ec74fe1..66524d746d4ef 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -47,22 +47,22 @@ type deprecationInfo struct {
 	info  telegraf.DeprecationInfo
 }
 
-func (di *deprecationInfo) determineEscalation(version *semver.Version) error {
+func (di *deprecationInfo) determineEscalation(version *semver.Version) {
 	di.Level = None
 	if di.info.Since == "" {
-		return nil
+		return
 	}
 
 	since, err := semver.NewVersion(di.info.Since + ".0")
 	if err != nil {
-		return fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since+".0", err)
+		panic(fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since+".0", err))
 	}
 
 	var removal *semver.Version
 	if di.info.RemovalIn != "" {
 		removal, err = semver.NewVersion(di.info.RemovalIn + ".0")
 		if err != nil {
-			return fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn+".0", err)
+			panic(fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn+".0", err))
 		}
 	} else {
 		removal = &semver.Version{Major: since.Major, Minor: since.Minor}
@@ -75,7 +75,6 @@ func (di *deprecationInfo) determineEscalation(version *semver.Version) error {
 	} else if !version.LessThan(*since) {
 		di.Level = Warn
 	}
-	return nil
 }
 
 // pluginDeprecationInfo holds all information about a deprecated plugin or it's options
diff --git a/docs/LICENSE_OF_DEPENDENCIES.md b/docs/LICENSE_OF_DEPENDENCIES.md
index e1caaf320a0f9..24f8760b4a95d 100644
--- a/docs/LICENSE_OF_DEPENDENCIES.md
+++ b/docs/LICENSE_OF_DEPENDENCIES.md
@@ -64,6 +64,7 @@ following works:
 - github.com/cespare/xxhash [MIT License](https://github.com/cespare/xxhash/blob/master/LICENSE.txt)
 - github.com/cisco-ie/nx-telemetry-proto [Apache License 2.0](https://github.com/cisco-ie/nx-telemetry-proto/blob/master/LICENSE)
 - github.com/containerd/containerd [Apache License 2.0](https://github.com/containerd/containerd/blob/master/LICENSE)
+- github.com/coreos/go-semver [Apache License 2.0](https://github.com/coreos/go-semver/blob/main/LICENSE)
 - github.com/couchbase/go-couchbase [MIT License](https://github.com/couchbase/go-couchbase/blob/master/LICENSE)
 - github.com/couchbase/gomemcached [MIT License](https://github.com/couchbase/gomemcached/blob/master/LICENSE)
 - github.com/couchbase/goutils [Apache License 2.0](https://github.com/couchbase/goutils/blob/master/LICENSE.md)

From b9bb624bec3e9ebccb2c149f9b0a9c4e7af81501 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 11:40:47 +0100
Subject: [PATCH 35/45] Improve error message.

---
 config/deprecation.go | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index 66524d746d4ef..24bab51985999 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -53,19 +53,19 @@ func (di *deprecationInfo) determineEscalation(version *semver.Version) {
 		return
 	}
 
-	since, err := semver.NewVersion(di.info.Since + ".0")
+	since, err := semver.NewVersion(di.info.Since+".0")
 	if err != nil {
-		panic(fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since+".0", err))
+		panic(fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since, err))
 	}
 
 	var removal *semver.Version
 	if di.info.RemovalIn != "" {
-		removal, err = semver.NewVersion(di.info.RemovalIn + ".0")
+		removal, err = semver.NewVersion(di.info.RemovalIn+".0")
 		if err != nil {
-			panic(fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn+".0", err))
+			panic(fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn, err))
 		}
 	} else {
-		removal = &semver.Version{Major: since.Major, Minor: since.Minor}
+		removal = &semver.Version{Major: since.Major,	Minor: since.Minor}
 		removal.BumpMajor()
 		di.info.RemovalIn = strings.TrimSuffix(removal.String(), ".0")
 	}

From 4b1e449eefbc55a8cb6a8c0fec7070e78cc62bd9 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 11:42:40 +0100
Subject: [PATCH 36/45] Formatting.

---
 config/deprecation.go | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index 24bab51985999..07f460d95d20c 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -53,19 +53,19 @@ func (di *deprecationInfo) determineEscalation(version *semver.Version) {
 		return
 	}
 
-	since, err := semver.NewVersion(di.info.Since+".0")
+	since, err := semver.NewVersion(di.info.Since + ".0")
 	if err != nil {
 		panic(fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since, err))
 	}
 
 	var removal *semver.Version
 	if di.info.RemovalIn != "" {
-		removal, err = semver.NewVersion(di.info.RemovalIn+".0")
+		removal, err = semver.NewVersion(di.info.RemovalIn + ".0")
 		if err != nil {
 			panic(fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn, err))
 		}
 	} else {
-		removal = &semver.Version{Major: since.Major,	Minor: since.Minor}
+		removal = &semver.Version{Major: since.Major, Minor: since.Minor}
 		removal.BumpMajor()
 		di.info.RemovalIn = strings.TrimSuffix(removal.String(), ".0")
 	}

From 57cb42942104d03c30573865c0e68af7c14a12bb Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 12:10:38 +0100
Subject: [PATCH 37/45] Update deprecation information from Changelog.

---
 plugins/inputs/deprecations.go  | 9 +++++----
 plugins/outputs/deprecations.go | 2 +-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/plugins/inputs/deprecations.go b/plugins/inputs/deprecations.go
index b8b4adfc55fef..084c206000d52 100644
--- a/plugins/inputs/deprecations.go
+++ b/plugins/inputs/deprecations.go
@@ -8,8 +8,9 @@ var Deprecations = map[string]telegraf.DeprecationInfo{
 		Notice: "use 'inputs.jolokia2' with the 'cassandra.conf' example configuration instead",
 	},
 	"io": {
-		Since:  "1.20",
-		Notice: "use 'inputs.diskio' instead",
+		Since:     "0.10",
+		RemovalIn: "2.0",
+		Notice:    "use 'inputs.diskio' instead",
 	},
 	"http_listener_v2": {
 		Since:  "1.9",
@@ -24,7 +25,7 @@ var Deprecations = map[string]telegraf.DeprecationInfo{
 		Notice: "use 'inputs.jolokia2' instead",
 	},
 	"kafka_consumer_legacy": {
-		Since:  "1.20",
+		Since:  "1.4",
 		Notice: "use 'inputs.kafka_consumer' instead, NOTE: 'kafka_consumer' only supports Kafka v0.8+",
 	},
 	"logparser": {
@@ -32,7 +33,7 @@ var Deprecations = map[string]telegraf.DeprecationInfo{
 		Notice: "use 'inputs.tail' with 'grok' data format instead",
 	},
 	"snmp_legacy": {
-		Since:  "1.20",
+		Since:  "1.0",
 		Notice: "use 'inputs.snmp' instead",
 	},
 	"tcp_listener": {
diff --git a/plugins/outputs/deprecations.go b/plugins/outputs/deprecations.go
index de09f51fedabc..70b61d6825822 100644
--- a/plugins/outputs/deprecations.go
+++ b/plugins/outputs/deprecations.go
@@ -4,7 +4,7 @@ import "github.com/influxdata/telegraf"
 
 var Deprecations = map[string]telegraf.DeprecationInfo{
 	"riemann_legacy": {
-		Since:  "1.20",
+		Since:  "1.3",
 		Notice: "use 'outputs.riemann' instead (see https://github.com/influxdata/telegraf/issues/1878)",
 	},
 }

From 5db8685b199377501c935aec8abd6852118c1ff8 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 11 Nov 2021 12:15:21 +0100
Subject: [PATCH 38/45] Revert "Remove color from deprecation output."

This reverts commit 3b95f310f0e8f99835f9e7555a6fbda25f66a402.
---
 config/deprecation.go | 11 ++++++-----
 go.mod                |  2 +-
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index 07f460d95d20c..dd91001e947c5 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/coreos/go-semver/semver"
+	"github.com/fatih/color"
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/aggregators"
@@ -172,12 +173,12 @@ func (c *Config) printUserDeprecation(category, name string, plugin interface{})
 
 	switch info.Level {
 	case Warn:
-		prefix := "W! DeprecationWarning"
+		prefix := "W! " + color.YellowString("DeprecationWarning")
 		printPluginDeprecationNotice(prefix, info.Name, info.info)
 		// We will not check for any deprecated options as the whole plugin is deprecated anyway.
 		return nil
 	case Error:
-		prefix := "E! DeprecationError"
+		prefix := "E! " + color.RedString("DeprecationError")
 		printPluginDeprecationNotice(prefix, info.Name, info.info)
 		// We are past the grace period
 		return fmt.Errorf("plugin deprecated")
@@ -188,10 +189,10 @@ func (c *Config) printUserDeprecation(category, name string, plugin interface{})
 	for _, option := range info.Options {
 		switch option.Level {
 		case Warn:
-			prefix := "W! DeprecationWarning"
+			prefix := "W! " + color.YellowString("DeprecationWarning")
 			printOptionDeprecationNotice(prefix, info.Name, option.Name, option.info)
 		case Error:
-			prefix := "E! DeprecationError"
+			prefix := "E! " + color.RedString("DeprecationError")
 			printOptionDeprecationNotice(prefix, info.Name, option.Name, option.info)
 			deprecatedOptions = append(deprecatedOptions, option.Name)
 		}
@@ -292,7 +293,7 @@ func (c *Config) PrintDeprecationList(plugins []pluginDeprecationInfo) {
 }
 
 func printHistoricPluginDeprecationNotice(category, name string, info telegraf.DeprecationInfo) {
-	prefix := "E! DeprecationError"
+	prefix := "E! " + color.RedString("DeprecationError")
 	log.Printf(
 		"%s: Plugin %q deprecated since version %s and removed: %s",
 		prefix, category+"."+name, info.Since, info.Notice,
diff --git a/go.mod b/go.mod
index a03a24cb6a87b..1e7ccaeafa75b 100644
--- a/go.mod
+++ b/go.mod
@@ -98,7 +98,7 @@ require (
 	github.com/eapache/queue v1.1.0 // indirect
 	github.com/echlebek/timeproxy v1.0.0 // indirect
 	github.com/eclipse/paho.mqtt.golang v1.3.0
-	github.com/fatih/color v1.10.0 // indirect
+	github.com/fatih/color v1.10.0
 	github.com/form3tech-oss/jwt-go v3.2.5+incompatible // indirect
 	github.com/ghodss/yaml v1.0.1-0.20190212211648-25d852aebe32
 	github.com/go-logfmt/logfmt v0.5.0

From 0a3411889c774fc0f3c33f38473e0dfa8a58ea10 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Tue, 16 Nov 2021 11:34:20 +0100
Subject: [PATCH 39/45] Handle processor and aggregator deprecations as well.

---
 config/deprecation.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/config/deprecation.go b/config/deprecation.go
index dd91001e947c5..74926e727e223 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -112,6 +112,10 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 
 	// First check if the whole plugin is deprecated
 	switch category {
+	case "aggregators":
+		if pi, deprecated := aggregators.Deprecations[name]; deprecated {
+			info.deprecationInfo.info = pi
+		}
 	case "inputs":
 		if pi, deprecated := inputs.Deprecations[name]; deprecated {
 			info.deprecationInfo.info = pi
@@ -120,6 +124,10 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 		if pi, deprecated := outputs.Deprecations[name]; deprecated {
 			info.deprecationInfo.info = pi
 		}
+	case "processors":
+		if pi, deprecated := processors.Deprecations[name]; deprecated {
+			info.deprecationInfo.info = pi
+		}
 	}
 	info.determineEscalation(c.version)
 	if info.Level != None {

From 253cc5940760aa29863a5afb8b4493f9c26ae9a3 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Tue, 16 Nov 2021 11:36:58 +0100
Subject: [PATCH 40/45] Rename 'Level' to 'LogLevel'.

---
 config/deprecation.go | 38 +++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index 74926e727e223..3d37ffb47999b 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -43,13 +43,13 @@ const (
 type deprecationInfo struct {
 	// Name of the plugin or plugin option
 	Name string
-	// Level of deprecation
-	Level Escalation
-	info  telegraf.DeprecationInfo
+	// LogLevel is the level of deprecation which currently corresponds to a log-level
+	LogLevel Escalation
+	info     telegraf.DeprecationInfo
 }
 
 func (di *deprecationInfo) determineEscalation(version *semver.Version) {
-	di.Level = None
+	di.LogLevel = None
 	if di.info.Since == "" {
 		return
 	}
@@ -72,9 +72,9 @@ func (di *deprecationInfo) determineEscalation(version *semver.Version) {
 	}
 
 	if !version.LessThan(*removal) {
-		di.Level = Error
+		di.LogLevel = Error
 	} else if !version.LessThan(*since) {
-		di.Level = Warn
+		di.LogLevel = Warn
 	}
 }
 
@@ -105,8 +105,8 @@ func (c *Config) incrementPluginOptionDeprecations(category string) {
 func (c *Config) collectDeprecationInfo(category, name string, plugin interface{}, all bool) pluginDeprecationInfo {
 	info := pluginDeprecationInfo{
 		deprecationInfo: deprecationInfo{
-			Name:  category + "." + name,
-			Level: None,
+			Name:     category + "." + name,
+			LogLevel: None,
 		},
 	}
 
@@ -130,7 +130,7 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 		}
 	}
 	info.determineEscalation(c.version)
-	if info.Level != None {
+	if info.LogLevel != None {
 		c.incrementPluginDeprecations(category)
 	}
 
@@ -161,7 +161,7 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 		}
 		optionInfo.determineEscalation(c.version)
 
-		if optionInfo.Level != None {
+		if optionInfo.LogLevel != None {
 			c.incrementPluginOptionDeprecations(category)
 		}
 
@@ -179,7 +179,7 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 func (c *Config) printUserDeprecation(category, name string, plugin interface{}) error {
 	info := c.collectDeprecationInfo(category, name, plugin, false)
 
-	switch info.Level {
+	switch info.LogLevel {
 	case Warn:
 		prefix := "W! " + color.YellowString("DeprecationWarning")
 		printPluginDeprecationNotice(prefix, info.Name, info.info)
@@ -195,7 +195,7 @@ func (c *Config) printUserDeprecation(category, name string, plugin interface{})
 	// Print deprecated options
 	deprecatedOptions := make([]string, 0)
 	for _, option := range info.Options {
-		switch option.Level {
+		switch option.LogLevel {
 		case Warn:
 			prefix := "W! " + color.YellowString("DeprecationWarning")
 			printOptionDeprecationNotice(prefix, info.Name, option.Name, option.info)
@@ -225,7 +225,7 @@ func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFil
 		plugin := creator()
 		info := c.collectDeprecationInfo("inputs", name, plugin, true)
 
-		if info.Level != None || len(info.Options) > 0 {
+		if info.LogLevel != None || len(info.Options) > 0 {
 			infos["inputs"] = append(infos["inputs"], info)
 		}
 	}
@@ -239,7 +239,7 @@ func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFil
 		plugin := creator()
 		info := c.collectDeprecationInfo("outputs", name, plugin, true)
 
-		if info.Level != None || len(info.Options) > 0 {
+		if info.LogLevel != None || len(info.Options) > 0 {
 			infos["outputs"] = append(infos["outputs"], info)
 		}
 	}
@@ -253,7 +253,7 @@ func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFil
 		plugin := creator()
 		info := c.collectDeprecationInfo("processors", name, plugin, true)
 
-		if info.Level != None || len(info.Options) > 0 {
+		if info.LogLevel != None || len(info.Options) > 0 {
 			infos["processors"] = append(infos["processors"], info)
 		}
 	}
@@ -267,7 +267,7 @@ func (c *Config) CollectDeprecationInfos(inFilter, outFilter, aggFilter, procFil
 		plugin := creator()
 		info := c.collectDeprecationInfo("aggregators", name, plugin, true)
 
-		if info.Level != None || len(info.Options) > 0 {
+		if info.LogLevel != None || len(info.Options) > 0 {
 			infos["aggregators"] = append(infos["aggregators"], info)
 		}
 	}
@@ -279,11 +279,11 @@ func (c *Config) PrintDeprecationList(plugins []pluginDeprecationInfo) {
 	sort.Slice(plugins, func(i, j int) bool { return plugins[i].Name < plugins[j].Name })
 
 	for _, plugin := range plugins {
-		switch plugin.Level {
+		switch plugin.LogLevel {
 		case Warn, Error:
 			_, _ = fmt.Printf(
 				"  %-40s %-5s since %-5s removal in %-5s %s\n",
-				plugin.Name, plugin.Level, plugin.info.Since, plugin.info.RemovalIn, plugin.info.Notice,
+				plugin.Name, plugin.LogLevel, plugin.info.Since, plugin.info.RemovalIn, plugin.info.Notice,
 			)
 		}
 
@@ -294,7 +294,7 @@ func (c *Config) PrintDeprecationList(plugins []pluginDeprecationInfo) {
 		for _, option := range plugin.Options {
 			_, _ = fmt.Printf(
 				"  %-40s %-5s since %-5s removal in %-5s %s\n",
-				plugin.Name+"/"+option.Name, option.Level, option.info.Since, option.info.RemovalIn, option.info.Notice,
+				plugin.Name+"/"+option.Name, option.LogLevel, option.info.Since, option.info.RemovalIn, option.info.Notice,
 			)
 		}
 	}

From 1a3b87d870f54c572a4ec34ba98a1e1f335b04f2 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Wed, 17 Nov 2021 14:23:41 +0100
Subject: [PATCH 41/45] Make all versions tri-dotted format.

---
 config/deprecation.go                         |  8 +++----
 plugins/aggregators/deprecations.go           |  1 +
 plugins/inputs/deprecations.go                | 23 ++++++++++---------
 plugins/inputs/http_response/http_response.go |  2 +-
 plugins/outputs/deprecations.go               |  3 ++-
 plugins/processors/deprecations.go            |  1 +
 6 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index 3d37ffb47999b..49d1eb1e68a62 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -54,21 +54,21 @@ func (di *deprecationInfo) determineEscalation(version *semver.Version) {
 		return
 	}
 
-	since, err := semver.NewVersion(di.info.Since + ".0")
+	since, err := semver.NewVersion(di.info.Since)
 	if err != nil {
 		panic(fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since, err))
 	}
 
 	var removal *semver.Version
 	if di.info.RemovalIn != "" {
-		removal, err = semver.NewVersion(di.info.RemovalIn + ".0")
+		removal, err = semver.NewVersion(di.info.RemovalIn)
 		if err != nil {
 			panic(fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn, err))
 		}
 	} else {
-		removal = &semver.Version{Major: since.Major, Minor: since.Minor}
+		removal = &semver.Version{Major: since.Major}
 		removal.BumpMajor()
-		di.info.RemovalIn = strings.TrimSuffix(removal.String(), ".0")
+		di.info.RemovalIn = removal.String()
 	}
 
 	if !version.LessThan(*removal) {
diff --git a/plugins/aggregators/deprecations.go b/plugins/aggregators/deprecations.go
index 8acf5305045a0..dd2302e0255c3 100644
--- a/plugins/aggregators/deprecations.go
+++ b/plugins/aggregators/deprecations.go
@@ -2,4 +2,5 @@ package aggregators
 
 import "github.com/influxdata/telegraf"
 
+// Deprecations lists the deprecated plugins
 var Deprecations = map[string]telegraf.DeprecationInfo{}
diff --git a/plugins/inputs/deprecations.go b/plugins/inputs/deprecations.go
index 084c206000d52..14a497baff30a 100644
--- a/plugins/inputs/deprecations.go
+++ b/plugins/inputs/deprecations.go
@@ -2,46 +2,47 @@ package inputs
 
 import "github.com/influxdata/telegraf"
 
+// Deprecations lists the deprecated plugins
 var Deprecations = map[string]telegraf.DeprecationInfo{
 	"cassandra": {
-		Since:  "1.7",
+		Since:  "1.7.0",
 		Notice: "use 'inputs.jolokia2' with the 'cassandra.conf' example configuration instead",
 	},
 	"io": {
-		Since:     "0.10",
-		RemovalIn: "2.0",
+		Since:     "0.10.0",
+		RemovalIn: "2.0.0",
 		Notice:    "use 'inputs.diskio' instead",
 	},
 	"http_listener_v2": {
-		Since:  "1.9",
+		Since:  "1.9.0",
 		Notice: "has been renamed to 'influxdb_listener', use 'inputs.influxdb_listener' or 'inputs.influxdb_listener_v2' instead",
 	},
 	"httpjson": {
-		Since:  "1.6",
+		Since:  "1.6.0",
 		Notice: "use 'inputs.http' instead",
 	},
 	"jolokia": {
-		Since:  "1.5",
+		Since:  "1.5.0",
 		Notice: "use 'inputs.jolokia2' instead",
 	},
 	"kafka_consumer_legacy": {
-		Since:  "1.4",
+		Since:  "1.4.0",
 		Notice: "use 'inputs.kafka_consumer' instead, NOTE: 'kafka_consumer' only supports Kafka v0.8+",
 	},
 	"logparser": {
-		Since:  "1.15",
+		Since:  "1.15.0",
 		Notice: "use 'inputs.tail' with 'grok' data format instead",
 	},
 	"snmp_legacy": {
-		Since:  "1.0",
+		Since:  "1.0.0",
 		Notice: "use 'inputs.snmp' instead",
 	},
 	"tcp_listener": {
-		Since:  "1.3",
+		Since:  "1.3.0",
 		Notice: "use 'inputs.socket_listener' instead",
 	},
 	"udp_listener": {
-		Since:  "1.3",
+		Since:  "1.3.0",
 		Notice: "use 'inputs.socket_listener' instead",
 	},
 }
diff --git a/plugins/inputs/http_response/http_response.go b/plugins/inputs/http_response/http_response.go
index ef5a1f4e85069..f0da6294aa263 100644
--- a/plugins/inputs/http_response/http_response.go
+++ b/plugins/inputs/http_response/http_response.go
@@ -28,7 +28,7 @@ const (
 
 // HTTPResponse struct
 type HTTPResponse struct {
-	Address         string   `toml:"address" deprecated:"1.12;use 'urls' instead"`
+	Address         string   `toml:"address" deprecated:"1.12.0;use 'urls' instead"`
 	URLs            []string `toml:"urls"`
 	HTTPProxy       string   `toml:"http_proxy"`
 	Body            string
diff --git a/plugins/outputs/deprecations.go b/plugins/outputs/deprecations.go
index 70b61d6825822..6c318cdf6bc4b 100644
--- a/plugins/outputs/deprecations.go
+++ b/plugins/outputs/deprecations.go
@@ -2,9 +2,10 @@ package outputs
 
 import "github.com/influxdata/telegraf"
 
+// Deprecations lists the deprecated plugins
 var Deprecations = map[string]telegraf.DeprecationInfo{
 	"riemann_legacy": {
-		Since:  "1.3",
+		Since:  "1.3.0",
 		Notice: "use 'outputs.riemann' instead (see https://github.com/influxdata/telegraf/issues/1878)",
 	},
 }
diff --git a/plugins/processors/deprecations.go b/plugins/processors/deprecations.go
index 365e829045ab8..fa344d8cb155e 100644
--- a/plugins/processors/deprecations.go
+++ b/plugins/processors/deprecations.go
@@ -2,4 +2,5 @@ package processors
 
 import "github.com/influxdata/telegraf"
 
+// Deprecations lists the deprecated plugins
 var Deprecations = map[string]telegraf.DeprecationInfo{}

From 18dd40c1d5dd20ae29677f3c232cc928e7a70cc2 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Wed, 17 Nov 2021 14:29:41 +0100
Subject: [PATCH 42/45] Print origin for version panic to ease debugging.

---
 config/deprecation.go | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index 49d1eb1e68a62..51e4a63a9f114 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -48,22 +48,22 @@ type deprecationInfo struct {
 	info     telegraf.DeprecationInfo
 }
 
-func (di *deprecationInfo) determineEscalation(version *semver.Version) {
+func (di *deprecationInfo) determineEscalation(version *semver.Version) error {
 	di.LogLevel = None
 	if di.info.Since == "" {
-		return
+		return nil
 	}
 
 	since, err := semver.NewVersion(di.info.Since)
 	if err != nil {
-		panic(fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since, err))
+		return fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since, err)
 	}
 
 	var removal *semver.Version
 	if di.info.RemovalIn != "" {
 		removal, err = semver.NewVersion(di.info.RemovalIn)
 		if err != nil {
-			panic(fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn, err))
+			return fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn, err)
 		}
 	} else {
 		removal = &semver.Version{Major: since.Major}
@@ -76,6 +76,7 @@ func (di *deprecationInfo) determineEscalation(version *semver.Version) {
 	} else if !version.LessThan(*since) {
 		di.LogLevel = Warn
 	}
+	return nil
 }
 
 // pluginDeprecationInfo holds all information about a deprecated plugin or it's options
@@ -129,7 +130,9 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 			info.deprecationInfo.info = pi
 		}
 	}
-	info.determineEscalation(c.version)
+	if err := info.determineEscalation(c.version); err != nil {
+		panic(fmt.Errorf("plugin %q: %v", info.Name, err))
+	}
 	if info.LogLevel != None {
 		c.incrementPluginDeprecations(category)
 	}
@@ -159,7 +162,9 @@ func (c *Config) collectDeprecationInfo(category, name string, plugin interface{
 		if len(tags) > 2 {
 			optionInfo.info.RemovalIn = tags[1]
 		}
-		optionInfo.determineEscalation(c.version)
+		if err := optionInfo.determineEscalation(c.version); err != nil {
+			panic(fmt.Errorf("plugin %q option %q: %v", info.Name, field.Name, err))
+		}
 
 		if optionInfo.LogLevel != None {
 			c.incrementPluginOptionDeprecations(category)

From 7bde16442555553557e2b82dc105bf092aa13269 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Wed, 17 Nov 2021 14:51:53 +0100
Subject: [PATCH 43/45] Switch to 'github.com/blang/semver' as we already have
 this as a (indirect) dependency.

---
 config/config.go                |  6 +++---
 config/deprecation.go           | 17 ++++++++---------
 docs/LICENSE_OF_DEPENDENCIES.md |  2 +-
 go.mod                          |  4 +++-
 go.sum                          |  1 +
 5 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/config/config.go b/config/config.go
index 4121c71687e66..396ebf271dec8 100644
--- a/config/config.go
+++ b/config/config.go
@@ -17,7 +17,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/coreos/go-semver/semver"
+	"github.com/blang/semver"
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/internal"
@@ -81,7 +81,7 @@ type Config struct {
 	AggProcessors models.RunningProcessors
 
 	Deprecations map[string][]int64
-	version      *semver.Version
+	version      semver.Version
 }
 
 // NewConfig creates a new struct to hold the Telegraf config.
@@ -115,7 +115,7 @@ func NewConfig() *Config {
 	if version == "" || version == "unknown" {
 		version = "0.0.0-unknown"
 	}
-	c.version = semver.New(version)
+	c.version = semver.MustParse(version)
 
 	tomlCfg := &toml.Config{
 		NormFieldName: toml.DefaultConfig.NormFieldName,
diff --git a/config/deprecation.go b/config/deprecation.go
index 51e4a63a9f114..8f99b5d034cf1 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -7,7 +7,7 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/coreos/go-semver/semver"
+	"github.com/blang/semver"
 	"github.com/fatih/color"
 
 	"github.com/influxdata/telegraf"
@@ -48,32 +48,31 @@ type deprecationInfo struct {
 	info     telegraf.DeprecationInfo
 }
 
-func (di *deprecationInfo) determineEscalation(version *semver.Version) error {
+func (di *deprecationInfo) determineEscalation(version semver.Version) error {
 	di.LogLevel = None
 	if di.info.Since == "" {
 		return nil
 	}
 
-	since, err := semver.NewVersion(di.info.Since)
+	since, err := semver.Parse(di.info.Since)
 	if err != nil {
 		return fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since, err)
 	}
 
-	var removal *semver.Version
+	var removal semver.Version
 	if di.info.RemovalIn != "" {
-		removal, err = semver.NewVersion(di.info.RemovalIn)
+		removal, err = semver.Parse(di.info.RemovalIn)
 		if err != nil {
 			return fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn, err)
 		}
 	} else {
-		removal = &semver.Version{Major: since.Major}
-		removal.BumpMajor()
+		removal = semver.Version{Major: since.Major + 1}
 		di.info.RemovalIn = removal.String()
 	}
 
-	if !version.LessThan(*removal) {
+	if version.GTE(removal) {
 		di.LogLevel = Error
-	} else if !version.LessThan(*since) {
+	} else if version.GTE(since) {
 		di.LogLevel = Warn
 	}
 	return nil
diff --git a/docs/LICENSE_OF_DEPENDENCIES.md b/docs/LICENSE_OF_DEPENDENCIES.md
index 24f8760b4a95d..3be61cec7fb9b 100644
--- a/docs/LICENSE_OF_DEPENDENCIES.md
+++ b/docs/LICENSE_OF_DEPENDENCIES.md
@@ -58,13 +58,13 @@ following works:
 - github.com/awslabs/kinesis-aggregation/go [Apache License 2.0](https://github.com/awslabs/kinesis-aggregation/blob/master/LICENSE.txt)
 - github.com/benbjohnson/clock [MIT License](https://github.com/benbjohnson/clock/blob/master/LICENSE)
 - github.com/beorn7/perks [MIT License](https://github.com/beorn7/perks/blob/master/LICENSE)
+- github.com/blang/semver [MIT License](https://github.com/blang/semver/blob/master/LICENSE)
 - github.com/bmatcuk/doublestar [MIT License](https://github.com/bmatcuk/doublestar/blob/master/LICENSE)
 - github.com/caio/go-tdigest [MIT License](https://github.com/caio/go-tdigest/blob/master/LICENSE)
 - github.com/cenkalti/backoff [MIT License](https://github.com/cenkalti/backoff/blob/master/LICENSE)
 - github.com/cespare/xxhash [MIT License](https://github.com/cespare/xxhash/blob/master/LICENSE.txt)
 - github.com/cisco-ie/nx-telemetry-proto [Apache License 2.0](https://github.com/cisco-ie/nx-telemetry-proto/blob/master/LICENSE)
 - github.com/containerd/containerd [Apache License 2.0](https://github.com/containerd/containerd/blob/master/LICENSE)
-- github.com/coreos/go-semver [Apache License 2.0](https://github.com/coreos/go-semver/blob/main/LICENSE)
 - github.com/couchbase/go-couchbase [MIT License](https://github.com/couchbase/go-couchbase/blob/master/LICENSE)
 - github.com/couchbase/gomemcached [MIT License](https://github.com/couchbase/gomemcached/blob/master/LICENSE)
 - github.com/couchbase/goutils [Apache License 2.0](https://github.com/couchbase/goutils/blob/master/LICENSE.md)
diff --git a/go.mod b/go.mod
index 1e7ccaeafa75b..5e307fc910065 100644
--- a/go.mod
+++ b/go.mod
@@ -78,7 +78,7 @@ require (
 	github.com/cisco-ie/nx-telemetry-proto v0.0.0-20190531143454-82441e232cf6
 	github.com/containerd/cgroups v1.0.1 // indirect
 	github.com/containerd/containerd v1.5.7 // indirect
-	github.com/coreos/go-semver v0.3.0
+	github.com/coreos/go-semver v0.3.0 // indirect
 	github.com/couchbase/go-couchbase v0.1.0
 	github.com/couchbase/gomemcached v0.1.3 // indirect
 	github.com/couchbase/goutils v0.1.0 // indirect
@@ -330,6 +330,8 @@ require (
 	sigs.k8s.io/yaml v1.2.0 // indirect
 )
 
+require github.com/blang/semver v3.5.1+incompatible
+
 require github.com/libp2p/go-reuseport v0.1.0
 
 require (
diff --git a/go.sum b/go.sum
index 727dc6e6d2611..323ef35feabff 100644
--- a/go.sum
+++ b/go.sum
@@ -425,6 +425,7 @@ github.com/bketelsen/crypt v0.0.3-0.20200106085610-5cbc8cc4026c/go.mod h1:MKsuJm
 github.com/bketelsen/crypt v0.0.4/go.mod h1:aI6NrJ0pMGgvZKL1iVgXLnfIFJtfV+bKCoqOes/6LfM=
 github.com/bkielbasa/cyclop v1.2.0/go.mod h1:qOI0yy6A7dYC4Zgsa72Ppm9kONl0RoIlPbzot9mhmeI=
 github.com/blang/semver v3.1.0+incompatible/go.mod h1:kRBLl5iJ+tD4TcOOxsy/0fnwebNt5EWlYSAyrTnjyyk=
+github.com/blang/semver v3.5.1+incompatible h1:cQNTCjp13qL8KC3Nbxr/y2Bqb63oX6wdnnjpJbkM4JQ=
 github.com/blang/semver v3.5.1+incompatible/go.mod h1:kRBLl5iJ+tD4TcOOxsy/0fnwebNt5EWlYSAyrTnjyyk=
 github.com/bmatcuk/doublestar/v3 v3.0.0 h1:TQtVPlDnAYwcrVNB2JiGuMc++H5qzWZd9PhkNo5WyHI=
 github.com/bmatcuk/doublestar/v3 v3.0.0/go.mod h1:6PcTVMw80pCY1RVuoqu3V++99uQB3vsSYKPTd8AWA0k=

From 28ae44775ccdb1ada3756213b1703c899226fbbe Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Wed, 17 Nov 2021 14:55:34 +0100
Subject: [PATCH 44/45] Drop potential pre-release tags for telegraf when
 comparing the versions.

---
 config/deprecation.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/config/deprecation.go b/config/deprecation.go
index 8f99b5d034cf1..1316b5b6664ab 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -48,7 +48,7 @@ type deprecationInfo struct {
 	info     telegraf.DeprecationInfo
 }
 
-func (di *deprecationInfo) determineEscalation(version semver.Version) error {
+func (di *deprecationInfo) determineEscalation(telegrafVersion semver.Version) error {
 	di.LogLevel = None
 	if di.info.Since == "" {
 		return nil
@@ -70,6 +70,12 @@ func (di *deprecationInfo) determineEscalation(version semver.Version) error {
 		di.info.RemovalIn = removal.String()
 	}
 
+	// Drop potential pre-release tags
+	version := semver.Version{
+		Major: telegrafVersion.Major,
+		Minor: telegrafVersion.Minor,
+		Patch: telegrafVersion.Patch,
+	}
 	if version.GTE(removal) {
 		di.LogLevel = Error
 	} else if version.GTE(since) {

From eeb9d7afb6c8c17ba68d04f2a8b3038eb6ca3fa0 Mon Sep 17 00:00:00 2001
From: Sven Rebhan <sven.rebhan@honda-ri.de>
Date: Thu, 18 Nov 2021 14:46:38 +0100
Subject: [PATCH 45/45] Revert "Switch to 'github.com/blang/semver' as we
 already have this as a (indirect) dependency."

This reverts commit 184d745cc59d366971395e8384366043241fda69.
---
 config/config.go                |  6 +++---
 config/deprecation.go           | 17 +++++++++--------
 docs/LICENSE_OF_DEPENDENCIES.md |  2 +-
 go.mod                          |  4 +---
 go.sum                          |  1 -
 5 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/config/config.go b/config/config.go
index 396ebf271dec8..4121c71687e66 100644
--- a/config/config.go
+++ b/config/config.go
@@ -17,7 +17,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/blang/semver"
+	"github.com/coreos/go-semver/semver"
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/internal"
@@ -81,7 +81,7 @@ type Config struct {
 	AggProcessors models.RunningProcessors
 
 	Deprecations map[string][]int64
-	version      semver.Version
+	version      *semver.Version
 }
 
 // NewConfig creates a new struct to hold the Telegraf config.
@@ -115,7 +115,7 @@ func NewConfig() *Config {
 	if version == "" || version == "unknown" {
 		version = "0.0.0-unknown"
 	}
-	c.version = semver.MustParse(version)
+	c.version = semver.New(version)
 
 	tomlCfg := &toml.Config{
 		NormFieldName: toml.DefaultConfig.NormFieldName,
diff --git a/config/deprecation.go b/config/deprecation.go
index 1316b5b6664ab..ab5d2a0caba46 100644
--- a/config/deprecation.go
+++ b/config/deprecation.go
@@ -7,7 +7,7 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/blang/semver"
+	"github.com/coreos/go-semver/semver"
 	"github.com/fatih/color"
 
 	"github.com/influxdata/telegraf"
@@ -48,25 +48,26 @@ type deprecationInfo struct {
 	info     telegraf.DeprecationInfo
 }
 
-func (di *deprecationInfo) determineEscalation(telegrafVersion semver.Version) error {
+func (di *deprecationInfo) determineEscalation(telegrafVersion *semver.Version) error {
 	di.LogLevel = None
 	if di.info.Since == "" {
 		return nil
 	}
 
-	since, err := semver.Parse(di.info.Since)
+	since, err := semver.NewVersion(di.info.Since)
 	if err != nil {
 		return fmt.Errorf("cannot parse 'since' version %q: %v", di.info.Since, err)
 	}
 
-	var removal semver.Version
+	var removal *semver.Version
 	if di.info.RemovalIn != "" {
-		removal, err = semver.Parse(di.info.RemovalIn)
+		removal, err = semver.NewVersion(di.info.RemovalIn)
 		if err != nil {
 			return fmt.Errorf("cannot parse 'removal' version %q: %v", di.info.RemovalIn, err)
 		}
 	} else {
-		removal = semver.Version{Major: since.Major + 1}
+		removal = &semver.Version{Major: since.Major}
+		removal.BumpMajor()
 		di.info.RemovalIn = removal.String()
 	}
 
@@ -76,9 +77,9 @@ func (di *deprecationInfo) determineEscalation(telegrafVersion semver.Version) e
 		Minor: telegrafVersion.Minor,
 		Patch: telegrafVersion.Patch,
 	}
-	if version.GTE(removal) {
+	if !version.LessThan(*removal) {
 		di.LogLevel = Error
-	} else if version.GTE(since) {
+	} else if !version.LessThan(*since) {
 		di.LogLevel = Warn
 	}
 	return nil
diff --git a/docs/LICENSE_OF_DEPENDENCIES.md b/docs/LICENSE_OF_DEPENDENCIES.md
index 3be61cec7fb9b..24f8760b4a95d 100644
--- a/docs/LICENSE_OF_DEPENDENCIES.md
+++ b/docs/LICENSE_OF_DEPENDENCIES.md
@@ -58,13 +58,13 @@ following works:
 - github.com/awslabs/kinesis-aggregation/go [Apache License 2.0](https://github.com/awslabs/kinesis-aggregation/blob/master/LICENSE.txt)
 - github.com/benbjohnson/clock [MIT License](https://github.com/benbjohnson/clock/blob/master/LICENSE)
 - github.com/beorn7/perks [MIT License](https://github.com/beorn7/perks/blob/master/LICENSE)
-- github.com/blang/semver [MIT License](https://github.com/blang/semver/blob/master/LICENSE)
 - github.com/bmatcuk/doublestar [MIT License](https://github.com/bmatcuk/doublestar/blob/master/LICENSE)
 - github.com/caio/go-tdigest [MIT License](https://github.com/caio/go-tdigest/blob/master/LICENSE)
 - github.com/cenkalti/backoff [MIT License](https://github.com/cenkalti/backoff/blob/master/LICENSE)
 - github.com/cespare/xxhash [MIT License](https://github.com/cespare/xxhash/blob/master/LICENSE.txt)
 - github.com/cisco-ie/nx-telemetry-proto [Apache License 2.0](https://github.com/cisco-ie/nx-telemetry-proto/blob/master/LICENSE)
 - github.com/containerd/containerd [Apache License 2.0](https://github.com/containerd/containerd/blob/master/LICENSE)
+- github.com/coreos/go-semver [Apache License 2.0](https://github.com/coreos/go-semver/blob/main/LICENSE)
 - github.com/couchbase/go-couchbase [MIT License](https://github.com/couchbase/go-couchbase/blob/master/LICENSE)
 - github.com/couchbase/gomemcached [MIT License](https://github.com/couchbase/gomemcached/blob/master/LICENSE)
 - github.com/couchbase/goutils [Apache License 2.0](https://github.com/couchbase/goutils/blob/master/LICENSE.md)
diff --git a/go.mod b/go.mod
index 5e307fc910065..1e7ccaeafa75b 100644
--- a/go.mod
+++ b/go.mod
@@ -78,7 +78,7 @@ require (
 	github.com/cisco-ie/nx-telemetry-proto v0.0.0-20190531143454-82441e232cf6
 	github.com/containerd/cgroups v1.0.1 // indirect
 	github.com/containerd/containerd v1.5.7 // indirect
-	github.com/coreos/go-semver v0.3.0 // indirect
+	github.com/coreos/go-semver v0.3.0
 	github.com/couchbase/go-couchbase v0.1.0
 	github.com/couchbase/gomemcached v0.1.3 // indirect
 	github.com/couchbase/goutils v0.1.0 // indirect
@@ -330,8 +330,6 @@ require (
 	sigs.k8s.io/yaml v1.2.0 // indirect
 )
 
-require github.com/blang/semver v3.5.1+incompatible
-
 require github.com/libp2p/go-reuseport v0.1.0
 
 require (
diff --git a/go.sum b/go.sum
index 323ef35feabff..727dc6e6d2611 100644
--- a/go.sum
+++ b/go.sum
@@ -425,7 +425,6 @@ github.com/bketelsen/crypt v0.0.3-0.20200106085610-5cbc8cc4026c/go.mod h1:MKsuJm
 github.com/bketelsen/crypt v0.0.4/go.mod h1:aI6NrJ0pMGgvZKL1iVgXLnfIFJtfV+bKCoqOes/6LfM=
 github.com/bkielbasa/cyclop v1.2.0/go.mod h1:qOI0yy6A7dYC4Zgsa72Ppm9kONl0RoIlPbzot9mhmeI=
 github.com/blang/semver v3.1.0+incompatible/go.mod h1:kRBLl5iJ+tD4TcOOxsy/0fnwebNt5EWlYSAyrTnjyyk=
-github.com/blang/semver v3.5.1+incompatible h1:cQNTCjp13qL8KC3Nbxr/y2Bqb63oX6wdnnjpJbkM4JQ=
 github.com/blang/semver v3.5.1+incompatible/go.mod h1:kRBLl5iJ+tD4TcOOxsy/0fnwebNt5EWlYSAyrTnjyyk=
 github.com/bmatcuk/doublestar/v3 v3.0.0 h1:TQtVPlDnAYwcrVNB2JiGuMc++H5qzWZd9PhkNo5WyHI=
 github.com/bmatcuk/doublestar/v3 v3.0.0/go.mod h1:6PcTVMw80pCY1RVuoqu3V++99uQB3vsSYKPTd8AWA0k=