Merge pull request #121 from elblivion/json-logging

JSON logging

README.md

@@ -103,6 +103,7 @@ spec:
 - you may override the secret annotation with the `--secret-annotation` flag
 - you may want to prevent watching certain namespaces with the `--namespaces-to-ignore` flag
 - you may want to prevent watching certain resources with the `--resources-to-ignore` flag
+- you can configure logging in JSON format with the `--log-format=json` option
 
 ## Deploying to Kubernetes
 
@@ -180,6 +181,8 @@ Reloader can be configured to ignore the resources `secrets` and `configmaps` by
 
 `Note`: At one time only one of these resource can be ignored, trying to do it will cause error in helm template compilation.
 
+You can also set the log format of Reloader to json by setting `logFormat` to `json` in values.yaml and apply the chart
+
 ## Help
 
 ### Documentation

deployments/kubernetes/chart/reloader/templates/deployment.yaml

@@ -92,6 +92,9 @@ spec:
             name: tmp-volume
       {{- end }}
         args:
+          {{- if .Values.reloader.logFormat }}
+          - "--log-format={{ .Values.reloader.logFormat }}"
+          {{- end }}
           {{- if .Values.reloader.ignoreSecrets }}
           - "--resources-to-ignore=secrets"
           {{- end }}

deployments/kubernetes/chart/reloader/values.yaml

@@ -12,6 +12,7 @@ reloader:
   isOpenshift: false
   ignoreSecrets: false
   ignoreConfigMaps: false
+  logFormat: "" #json
   watchGlobally: true
   # Set to true if you have a pod security policy that enforces readOnlyRootFilesystem
   readOnlyRootFileSystem: false

deployments/kubernetes/templates/chart/values.yaml.tmpl

@@ -12,6 +12,7 @@ reloader:
   isOpenshift: false
   ignoreSecrets: false
   ignoreConfigMaps: false
+  logFormat: "" #json
   watchGlobally: true
   # Set to true if you have a pod security policy that enforces readOnlyRootFilesystem
   readOnlyRootFileSystem: false

internal/pkg/cmd/reloader.go

@@ -26,12 +26,31 @@ func NewReloaderCommand() *cobra.Command {
 	cmd.PersistentFlags().StringVar(&options.ConfigmapUpdateOnChangeAnnotation, "configmap-annotation", "configmap.reloader.stakater.com/reload", "annotation to detect changes in configmaps")
 	cmd.PersistentFlags().StringVar(&options.SecretUpdateOnChangeAnnotation, "secret-annotation", "secret.reloader.stakater.com/reload", "annotation to detect changes in secrets")
 	cmd.PersistentFlags().StringVar(&options.ReloaderAutoAnnotation, "auto-annotation", "reloader.stakater.com/auto", "annotation to detect changes in secrets")
+	cmd.PersistentFlags().StringVar(&options.LogFormat, "log-format", "", "Log format to use (empty string for text, or JSON")
 	cmd.PersistentFlags().StringSlice("resources-to-ignore", []string{}, "list of resources to ignore (valid options 'configMaps' or 'secrets')")
 	cmd.PersistentFlags().StringSlice("namespaces-to-ignore", []string{}, "list of namespaces to ignore")
 	return cmd
 }
 
+func configureLogging(logFormat string) error {
+	switch logFormat {
+	case "json":
+		logrus.SetFormatter(&logrus.JSONFormatter{})
+	default:
+		// just let the library use default on empty string.
+		if logFormat != "" {
+			return fmt.Errorf("unsupported logging formatter: %q", logFormat)
+		}
+	}
+	return nil
+}
+
 func startReloader(cmd *cobra.Command, args []string) {
+	err := configureLogging(options.LogFormat)
+	if err != nil {
+		logrus.Warn(err)
+	}
+
 	logrus.Info("Starting Reloader")
 	currentNamespace := os.Getenv("KUBERNETES_NAMESPACE")
 	if len(currentNamespace) == 0 {

internal/pkg/options/flags.go

@@ -7,4 +7,6 @@ var (
 	SecretUpdateOnChangeAnnotation = "secret.reloader.stakater.com/reload"
 	// ReloaderAutoAnnotation is an annotation to detect changes in secrets
 	ReloaderAutoAnnotation = "reloader.stakater.com/auto"
+	// LogFormat is the log format to use (json, or empty string for default)
+	LogFormat = ""
 )