ref(config): centralize standard config loading (#137)

into a package that has a simple convenience function and the standard app name

Author: arschles

config.go

@@ -1,27 +1,25 @@
 package main
 
 import (
-	"fmt"
-
+	"github.com/deis/steward/config"
 	"github.com/juju/loggo"
-	"github.com/kelseyhightower/envconfig"
 )
 
-type errModeUnsupported struct {
-	mode string
-}
-
-func (e errModeUnsupported) Error() string {
-	return fmt.Sprintf("mode '%s' is unsupported", e.mode)
-}
-
-type config struct {
+type rootConfig struct {
 	Mode            string   `envconfig:"MODE" default:"cf"`
 	LogLevel        string   `envconfig:"LOG_LEVEL" default:"info"`
 	WatchNamespaces []string `envconfig:"WATCH_NAMESPACES" default:"default"`
 }
 
-func (c config) logLevel() loggo.Level {
+func getRootConfig() (*rootConfig, error) {
+	ret := new(rootConfig)
+	if err := config.Load(ret); err != nil {
+		return nil, err
+	}
+	return ret, nil
+}
+
+func (c rootConfig) logLevel() loggo.Level {
 	switch c.LogLevel {
 	case "trace":
 		return loggo.TRACE
@@ -39,11 +37,3 @@ func (c config) logLevel() loggo.Level {
 		return loggo.INFO
 	}
 }
-
-func getConfig(appName string) (*config, error) {
-	spec := new(config)
-	if err := envconfig.Process(appName, spec); err != nil {
-		return nil, err
-	}
-	return spec, nil
-}

config/common.go

@@ -0,0 +1,15 @@
+package config
+
+import (
+	"github.com/kelseyhightower/envconfig"
+)
+
+const (
+	// AppName is the standard app name to use in fetching configs
+	AppName = "steward"
+)
+
+// Load is a convenience function for calling envconfig.Process(AppName, ret) (godoc.org/github.com/kelseyhightower/envconfig#Process)
+func Load(ret interface{}) error {
+	return envconfig.Process(AppName, ret)
+}

main.go

@@ -9,10 +9,6 @@ import (
 	"github.com/juju/loggo"
 )
 
-const (
-	appName = "steward"
-)
-
 var (
 	logger  = loggo.GetLogger("")
 	version = "dev"
@@ -25,7 +21,7 @@ func exitWithCode(cancelFn func(), exitCode int) {
 
 func main() {
 	logger.Infof("steward version %s started", version)
-	cfg, err := getConfig(appName)
+	cfg, err := getRootConfig()
 	if err != nil {
 		logger.Criticalf("error getting config (%s)", err)
 		os.Exit(1)

mode/utils/cf_config.go

@@ -1,8 +1,8 @@
 package utils
 
 import (
+	"github.com/deis/steward/config"
 	"github.com/deis/steward/web"
-	"github.com/kelseyhightower/envconfig"
 )
 
 type cfConfig struct {
@@ -15,7 +15,7 @@ type cfConfig struct {
 
 func getCfConfig() (*cfConfig, error) {
 	ret := new(cfConfig)
-	if err := envconfig.Process(appName, ret); err != nil {
+	if err := config.Load(ret); err != nil {
 		return nil, err
 	}
 	return ret, nil

mode/utils/common.go

@@ -4,10 +4,6 @@ import (
 	"github.com/juju/loggo"
 )
 
-const (
-	appName = "steward"
-)
-
 var (
 	logger = loggo.GetLogger("mode.utils")
 )