search for default config on startup

CHANGELOG.md

@@ -13,6 +13,9 @@
 - [#710](https://github.com/influxdata/kapacitor/pull/710): Fix infinite loop when parsing unterminated regex in TICKscript.
 - [#711](https://github.com/influxdata/kapacitor/issue/711): Fix where database name with quotes breaks subscription startup logic.
 - [#719](https://github.com/influxdata/kapacitor/pull/719): Fix panic on replay.
+- [#723](https://github.com/influxdata/kapacitor/pull/723): BREAKING: Search for valid configuration on startup in ~/.kapacitor and /etc/kapacitor/.
+    This is so that the -config CLI flag is not required if the configuration is found in a standard location.
+    The configuration file being used is always logged to STDERR.
 
 ## v1.0.0-beta3 [2016-07-09]
 

cmd/kapacitord/run/command.go

@@ -70,7 +70,7 @@ func (cmd *Command) Run(args ...string) error {
 	fmt.Print(logo)
 
 	// Parse config
-	config, err := cmd.ParseConfig(options.ConfigPath)
+	config, err := cmd.ParseConfig(FindConfigPath(options.ConfigPath))
 	if err != nil {
 		return fmt.Errorf("parse config: %s", err)
 	}
@@ -206,11 +206,11 @@ func (cmd *Command) writePIDFile(path string) error {
 func (cmd *Command) ParseConfig(path string) (*server.Config, error) {
 	// Use demo configuration if no config path is specified.
 	if path == "" {
-		log.Println("no configuration provided, using default settings")
+		log.Println("No configuration provided, using default settings")
 		return server.NewDemoConfig()
 	}
 
-	log.Printf("Using configuration at: %s\n", path)
+	log.Println("Using configuration at:", path)
 
 	config := server.NewConfig()
 	if _, err := toml.DecodeFile(path, &config); err != nil {

cmd/kapacitord/run/config_command.go

@@ -4,6 +4,7 @@ import (
 	"flag"
 	"fmt"
 	"io"
+	"log"
 	"os"
 
 	"github.com/BurntSushi/toml"
@@ -38,7 +39,7 @@ func (cmd *PrintConfigCommand) Run(args ...string) error {
 	}
 
 	// Parse config from path.
-	config, err := cmd.parseConfig(*configPath)
+	config, err := cmd.parseConfig(FindConfigPath(*configPath))
 	if err != nil {
 		return fmt.Errorf("parse config: %s", err)
 	}
@@ -64,14 +65,47 @@ func (cmd *PrintConfigCommand) Run(args ...string) error {
 	return nil
 }
 
+// FindConfigPath returns the config path specified or searches for a valid config path.
+// It will return a path by searching in this order:
+//   1. The given configPath
+//   2. The environment variable KAPACITOR_CONFIG_PATH
+//   3. The first non empty kapacitor.conf file in the path:
+//        - ~/.kapacitor/
+//        - /etc/kapacitor/
+func FindConfigPath(configPath string) string {
+	if configPath != "" {
+		if configPath == os.DevNull {
+			return ""
+		}
+		return configPath
+	} else if envVar := os.Getenv("KAPACITOR_CONFIG_PATH"); envVar != "" {
+		return envVar
+	}
+
+	for _, path := range []string{
+		os.ExpandEnv("${HOME}/.kapacitor/kapacitor.conf"),
+		"/etc/kapacitor/kapacitor.conf",
+	} {
+		if fi, err := os.Stat(path); err == nil && fi.Size() != 0 {
+			return path
+		}
+	}
+	return ""
+}
+
 // ParseConfig parses the config at path.
 // Returns a demo configuration if path is blank.
 func (cmd *PrintConfigCommand) parseConfig(path string) (*server.Config, error) {
+	config, err := server.NewDemoConfig()
+	if err != nil {
+		config = server.NewConfig()
+	}
+
 	if path == "" {
-		return server.NewDemoConfig()
+		return config, nil
 	}
 
-	config := server.NewConfig()
+	log.Println("Merging with configuration at:", path)
 	if _, err := toml.DecodeFile(path, &config); err != nil {
 		return nil, err
 	}

tickdoc.conf

@@ -1,10 +1,10 @@
-root = "/kapacitor/v1.0b/nodes"
+root = "/kapacitor/v1.0/nodes"
 page-header = '''---
 title: {{ .Title }}
 note: Auto generated by tickdoc
 
 menu:
-  kapacitor_10b:
+  kapacitor_1:
     name: {{ .Name }}
     identifier: {{ .Identifier }}
     weight: {{ .Weight }}