Adding the ability to configure LOG_LEVEL dynamically from environmen…

…t variables. (#25)

This PR adds a feature that allows changing the application log level
dynamically.

application/application.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"keess/kube_syncer"
 
+	"github.com/fsnotify/fsnotify"
 	"github.com/spf13/viper"
 	"github.com/urfave/cli/v2"
 )
@@ -12,7 +13,7 @@ import (
 func New() *cli.App {
 	app := cli.NewApp()
 	app.Name = "Keess"
-	app.Version = "v0.1.13"
+	app.Version = "v0.2.13"
 	app.Usage = "Keep stuff synchronized."
 	app.Description = "Keep secrets and configmaps synchronized."
 	app.Suggest = true
@@ -62,10 +63,16 @@ func run(c *cli.Context) error {
 	viper.SetEnvPrefix("KEESS")
 	viper.AutomaticEnv()
 
+	viper.WatchConfig()
+
 	kubeConfigPath := c.String("config")
 	sourceContext := c.String("sourceContext")
 	destinationContexts := c.StringSlice("destinationContexts")
 	developmentMode := c.Bool("developmentMode")
+	initialLogLevel := viper.GetString("LOG_LEVEL")
+	if initialLogLevel == "" {
+		initialLogLevel = "INFO"
+	}
 
 	if kubeConfigPath == "" {
 		kubeConfigPath = viper.GetString("CONFIG_PATH")
@@ -86,7 +93,11 @@ func run(c *cli.Context) error {
 	fmt.Printf("Starting %s %s\n", c.App.Name, c.App.Version)
 
 	var syncer kube_syncer.Syncer
-	err := syncer.Start(kubeConfigPath, developmentMode, sourceContext, destinationContexts)
+	err := syncer.Start(kubeConfigPath, developmentMode, initialLogLevel, sourceContext, destinationContexts)
+
+	viper.OnConfigChange(func(e fsnotify.Event) {
+		syncer.SetLogLevel(viper.GetString("LOG_LEVEL"))
+	})
 
 	if err == nil {
 		return syncer.Run()

chart/Chart.yaml

@@ -15,10 +15,10 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: 0.1.13
+version: 0.2.13
 
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application. Versions are not expected to
 # follow Semantic Versioning. They should reflect the version the application is using.
 # It is recommended to use it with quotes.
-appVersion: "v0.1.13"
+appVersion: "v0.2.13"

chart/templates/deployment.yaml

@@ -46,6 +46,10 @@ spec:
           - name: KEESS_DEVELOPMENT_MODE
             value: "{{ .Values.developmentMode }}"
           {{- end }}
+          {{- if .Values.logLevel }}
+          - name: LOG_LEVEL
+            value: "{{ .Values.logLevel }}"
+          {{- end }}          
           imagePullPolicy: {{ .Values.image.pullPolicy }}
           volumeMounts:
           - name: config

chart/values.yaml

@@ -8,6 +8,13 @@ image:
   # Overrides the image tag whose default is the chart appVersion.
   tag: "main-8eec28338b8f92ef13248ef2b01d453de0489d29-17"
 
+
+# Default Keess config
+# clusterName: ""
+# remoteClusters: ""
+# developmentMode: "true"
+# logLevel: "INFO"
+
 imagePullSecrets: []
 nameOverride: ""
 fullnameOverride: ""

kube_syncer/configmap_watcher.go

@@ -30,7 +30,7 @@ func (w ConfigMapWatcher) Watch() <-chan abstractions.ISynchronizable {
 		})
 
 		if err != nil {
-			panic(err)
+			w.logger.Error(err)
 		}
 
 		w.logger.Info("Watching configMaps events.")

kube_syncer/namespace_watcher.go

@@ -28,7 +28,7 @@ func (w NamespaceWatcher) Watch() <-chan abstractions.ISynchronizable {
 		})
 
 		if err != nil {
-			panic(err)
+			w.logger.Error(err)
 		}
 
 		w.logger.Info("Watching namespaces events.")

kube_syncer/secret_watcher.go

@@ -30,7 +30,7 @@ func (w SecretWatcher) Watch() <-chan abstractions.ISynchronizable {
 		})
 
 		if err != nil {
-			panic(err)
+			w.logger.Error(err)
 		}
 
 		w.logger.Info("Watching secrets events.")

kube_syncer/syncer.go

@@ -3,6 +3,7 @@ package kube_syncer
 import (
 	"context"
 	"flag"
+	"os"
 	"path/filepath"
 	"time"
 
@@ -32,6 +33,8 @@ type Syncer struct {
 
 	// The logger object.
 	logger *zap.SugaredLogger
+
+	atom zap.AtomicLevel
 }
 
 func init() {
@@ -41,24 +44,42 @@ func init() {
 	abstractions.EntitiesToLabeledNamespaces["Secrets"] = make(map[string]runtime.Object)
 }
 
+func (s *Syncer) SetLogLevel(logLevel string) {
+	level, err := zapcore.ParseLevel(logLevel)
+
+	if err == nil {
+		s.atom.SetLevel(level)
+	} else {
+		s.logger.Error(err)
+	}
+}
+
 // Load the kubeClient based in the given configuration.
-func (s *Syncer) Start(kubeConfigPath string, developmentMode bool, sourceContext string, destinationContexts []string) error {
-	var loggerConfig zap.Config
+func (s *Syncer) Start(kubeConfigPath string, developmentMode bool, initialLogLevel string, sourceContext string, destinationContexts []string) error {
+	s.atom = zap.NewAtomicLevel()
+
+	// To keep the example deterministic, disable timestamps in the output.
+	var encoderCfg zapcore.EncoderConfig
 
 	if developmentMode {
-		loggerConfig = zap.NewDevelopmentConfig()
+		encoderCfg = zap.NewDevelopmentEncoderConfig()
 	} else {
-		loggerConfig = zap.NewProductionConfig()
+		encoderCfg = zap.NewProductionEncoderConfig()
 	}
 
-	loggerConfig.EncoderConfig.TimeKey = "timestamp"
-	loggerConfig.EncoderConfig.EncodeTime = zapcore.TimeEncoderOfLayout(time.RFC3339)
+	encoderCfg.TimeKey = "timestamp"
+	encoderCfg.EncodeTime = zapcore.TimeEncoderOfLayout(time.RFC3339)
 
-	zapLogger, err := loggerConfig.Build()
-	if err != nil {
-		s.logger.Error(err)
-	}
-	abstractions.Logger = zapLogger.Sugar()
+	logger := zap.New(zapcore.NewCore(
+		zapcore.NewJSONEncoder(encoderCfg),
+		zapcore.Lock(os.Stdout),
+		s.atom,
+	))
+	defer logger.Sync()
+
+	s.SetLogLevel(initialLogLevel)
+
+	abstractions.Logger = logger.Sugar()
 	s.logger = abstractions.Logger
 
 	s.sourceContext = sourceContext