migrating golangci-lint to v1_30_0 and enabling some new linters

.golangci.yml

@@ -80,17 +80,23 @@ linters:
   enable-all: true
   disable:
     - lll
-    - prealloc
-    - gochecknoinits
     - gochecknoglobals
     - errcheck
     - unparam
     - gosec
     - interfacer
     - dupl
-    # TODO: need to enable this two for better coding guidelines in terms of space between condition
+    - exhaustive
     - whitespace
     - wsl
+    - gci
+    - godot
+    - gomnd
+    - nestif
+    - nlreturn
+    # TODO: enable this linters later
+    - goerr113
+    - gochecknoinits
   fast: true
 
 # output configuration options

.travis.yml

@@ -8,7 +8,7 @@ go:
   - "1.14.x"
 
 before_install:
-  - "curl -sfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.21.0"
+  - "curl -sfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.30.0"
 
 install:
   - echo -e "Host heroku.com\n\tStrictHostKeyChecking no\n" >> ~/.ssh/config
@@ -18,8 +18,8 @@ script:
   - export PATH=$(go env GOPATH)/bin:$PATH
   - export GO111MODULE=on
   - go mod download
-  - golangci-lint run
-  - go test -v -covermode atomic -race -timeout 70s -cpu 4 -parallel 8 -coverprofile ./coverage.out $(go list ./...)
+  - golangci-lint run -c .golangci.yml -v
+  - go test -v -covermode atomic -race -timeout 120s -cpu 4 -parallel 8 -coverprofile ./coverage.out $(go list ./...)
   - "! go tool cover -func coverage.out | grep -v 100.0%"
 
 after_script:

boltcycle/boltcycle.go

@@ -75,11 +75,13 @@ func (s *Stats) AtomicClone() Stats {
 	}
 }
 
-var errUnableToFindRootBucket = errors.New("unable to find root bucket")
-var errUnexpectedBucketBytes = errors.New("bucket bytes not in uint64 form")
-var errUnexpectedNonBucket = errors.New("unexpected non bucket")
-var errNoLastBucket = errors.New("unable to find a last bucket")
-var errOrderingWrong = errors.New("ordering wrong")
+var (
+	errUnableToFindRootBucket = errors.New("unable to find root bucket")
+	errUnexpectedBucketBytes  = errors.New("bucket bytes not in uint64 form")
+	errUnexpectedNonBucket    = errors.New("unexpected non bucket")
+	errNoLastBucket           = errors.New("unable to find a last bucket")
+	errOrderingWrong          = errors.New("ordering wrong")
+)
 
 // KvPair is a pair of key/value that you want to write during a write call
 type KvPair struct {

datapoint/dpsink/counter.go

@@ -1,11 +1,10 @@
 package dpsink
 
 import (
+	"context"
 	"sync/atomic"
 	"time"
 
-	"context"
-
 	"github.com/signalfx/golib/v3/datapoint"
 	"github.com/signalfx/golib/v3/event"
 	"github.com/signalfx/golib/v3/log"

datapoint/dpsink/filter.go

@@ -1,9 +1,8 @@
 package dpsink
 
 import (
-	"sync/atomic"
-
 	"context"
+	"sync/atomic"
 
 	"github.com/signalfx/golib/v3/datapoint"
 )

datapoint/dpsink/ratelimitlogger.go

@@ -1,11 +1,10 @@
 package dpsink
 
 import (
+	"context"
 	"sync/atomic"
 	"time"
 
-	"context"
-
 	"github.com/signalfx/golib/v3/datapoint"
 	"github.com/signalfx/golib/v3/event"
 	"github.com/signalfx/golib/v3/log"

datapoint/dptest/basicsink.go

@@ -1,9 +1,8 @@
 package dptest
 
 import (
-	"sync"
-
 	"context"
+	"sync"
 
 	"github.com/signalfx/golib/v3/datapoint"
 	"github.com/signalfx/golib/v3/event"

disco/disco.go

@@ -2,26 +2,21 @@
 package disco
 
 import (
+	"bytes"
 	"crypto/rand"
-	"io"
-
+	"encoding/binary"
 	"encoding/json"
-	"fmt"
-	"sync/atomic"
-	"time"
-
 	"expvar"
-
+	"fmt"
+	"io"
+	"sort"
 	"strings"
 	"sync"
-
-	"bytes"
-	"encoding/binary"
-	"sort"
-
-	"github.com/signalfx/golib/v3/errors"
+	"sync/atomic"
+	"time"
 
 	"github.com/samuel/go-zookeeper/zk"
+	"github.com/signalfx/golib/v3/errors"
 	"github.com/signalfx/golib/v3/log"
 	"github.com/signalfx/golib/v3/logkey"
 	"github.com/signalfx/golib/v3/pointer"

distconf/distconf.go

@@ -1,14 +1,11 @@
 package distconf
 
 import (
-	"sync"
-
-	"time"
-
-	"math"
-
 	"expvar"
+	"math"
 	"runtime"
+	"sync"
+	"time"
 
 	"github.com/signalfx/golib/v3/log"
 	"github.com/signalfx/golib/v3/logkey"

distconf/ini.go

@@ -29,7 +29,6 @@ func Ini(filename string) (Reader, error) {
 		filename: filename,
 		file:     file,
 	}, nil
-
 }
 
 // IniLoader is a helper for loading from Ini files

distconf/zk.go

@@ -3,9 +3,7 @@ package distconf
 
 import (
 	"fmt"
-
 	"sync"
-
 	"time"
 
 	"github.com/samuel/go-zookeeper/zk"

env/env.go

@@ -81,7 +81,7 @@ func GetCommaSeparatedStringEnvVar(envVar string, def []string) []string {
 	}
 
 	// return a copy of the default
-	var ret = make([]string, len(def))
+	ret := make([]string, len(def))
 	_ = copy(ret, def)
 
 	return ret

errors/compatibility.go

@@ -17,9 +17,11 @@ type hasMessage interface {
 	Message() string
 }
 
-var _ causableError = &ErrorChain{}
-var _ hasUnderline = &ErrorChain{}
-var _ hasMessage = &ErrorChain{}
+var (
+	_ causableError = &ErrorChain{}
+	_ hasUnderline  = &ErrorChain{}
+	_ hasMessage    = &ErrorChain{}
+)
 
 // Cause lets me simulate errgo
 func (e *ErrorChain) Cause() error {

event/event.go

@@ -65,7 +65,7 @@ func New(eventType string, category Category, dimensions map[string]string, time
 
 // ToProtoEC - Converts a protbuf EventCategory to type event.Category
 func ToProtoEC(ec sfxmodel.EventCategory) Category {
-	var response = USERDEFINED
+	response := USERDEFINED
 	// Check if the event.Category does not have a corresponding sfxmodel.EventCategory
 	if _, ok := sfxmodel.EventCategory_name[int32(ec)]; ok {
 		response = Category(ec)

httpdebug/server.go

@@ -33,10 +33,8 @@ var DefaultConfig = &Config{
 	WriteTimeout: pointer.Duration(time.Duration(0)),
 }
 
-var (
-	// LogKeyHTTPClass is appended as a key to subloggers of the debug server
-	LogKeyHTTPClass = log.Key("http_class")
-)
+// LogKeyHTTPClass is appended as a key to subloggers of the debug server
+var LogKeyHTTPClass = log.Key("http_class")
 
 // New creates a new debug server
 func New(conf *Config) *Server {

metadata/aws/ec2metadata/ec2.go

@@ -1,6 +1,7 @@
 package ec2metadata
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -83,10 +84,16 @@ func requestAWSInfo(url string) (metadata *EC2Metadata, err error) {
 	httpClient := &http.Client{Timeout: 200 * time.Millisecond}
 
 	// make the request
-	var res *http.Response
-	if res, err = httpClient.Get(url); err == nil {
-		err = json.NewDecoder(res.Body).Decode(metadata)
-		_ = res.Body.Close()
+	var (
+		res *http.Response
+		req *http.Request
+	)
+
+	if req, err = http.NewRequestWithContext(context.Background(), http.MethodGet, url, nil); err == nil {
+		if res, err = httpClient.Do(req); err == nil {
+			err = json.NewDecoder(res.Body).Decode(metadata)
+			_ = res.Body.Close()
+		}
 	}
 
 	return metadata, err

metadata/hostmetadata/host.go

@@ -30,10 +30,12 @@ const cpuTimeout = 10 * time.Second
 
 // Map library functions to unexported package variables for testing purposes.
 // It would be great if we could patch this somehow
-var cpuInfo = cpu.InfoWithContext
-var cpuCounts = cpu.CountsWithContext
-var memVirtualMemory = mem.VirtualMemory
-var hostInfo = host.Info
+var (
+	cpuInfo          = cpu.InfoWithContext
+	cpuCounts        = cpu.CountsWithContext
+	memVirtualMemory = mem.VirtualMemory
+	hostInfo         = host.Info
+)
 
 // CPU information about the host
 type CPU struct {
@@ -122,9 +124,11 @@ func int8ArrayToByteArray(in []int8) []byte {
 }
 
 // GetOS returns a struct with information about the host os
-func GetOS() (info *OS, err error) {
-	info = &OS{}
-	hInfo, err := hostInfo()
+func GetOS() (*OS, error) {
+	var (
+		info       = &OS{}
+		hInfo, err = hostInfo()
+	)
 
 	if err != nil {
 		return info, err
@@ -183,9 +187,12 @@ func GetMemory() (*Memory, error) {
 }
 
 func getStringFromFile(pattern string, path string) (string, error) {
-	var err error
-	var file []byte
-	var reg = regexp.MustCompile(pattern)
+	var (
+		err  error
+		file []byte
+		reg  = regexp.MustCompile(pattern)
+	)
+
 	if file, err = ioutil.ReadFile(path); err == nil {
 		if match := reg.FindSubmatch(file); len(match) > 1 {
 			return string(match[1]), nil

safeexec/safeexec.go

@@ -3,7 +3,6 @@ package safeexec
 import (
 	"bytes"
 	"os/exec"
-
 	"strings"
 
 	"github.com/signalfx/golib/v3/errors"

sfxclient/datapointcreation.go

@@ -1,9 +1,8 @@
 package sfxclient
 
 import (
-	"time"
-
 	"sync/atomic"
+	"time"
 
 	"github.com/signalfx/golib/v3/datapoint"
 )

sfxclient/gometrics.go

@@ -16,6 +16,7 @@ var GoMetricsSource Collector = &goMetrics{}
 
 type goMetrics struct{}
 
+// Datapoints will report current runtime stats of the process
 func (g *goMetrics) Datapoints() []*datapoint.Datapoint {
 	mstat := runtime.MemStats{}
 	runtime.ReadMemStats(&mstat)

sfxclient/httpsink.go

@@ -429,11 +429,10 @@ func (h *HTTPSink) coreEventToProtobuf(event *event.Event) *sfxmodel.Event {
 		Timestamp:  ts,
 	}
 	return ev
-
 }
 
 func mapToProperties(properties map[string]interface{}) []*sfxmodel.Property {
-	var response = make([]*sfxmodel.Property, 0, len(properties))
+	response := make([]*sfxmodel.Property, 0, len(properties))
 	for k, v := range properties {
 		kv := k
 		pv := rawToProtobuf(v)
@@ -469,7 +468,6 @@ func (h *HTTPSink) AddSpans(ctx context.Context, traces []*trace.Span) (err erro
 		}
 		return h.getReader(b)
 	}, h.contentTypeHeader, h.TraceEndpoint, spanResponseValidator)
-
 }
 
 func jsonMarshal(v []*trace.Span) ([]byte, error) {