logger: mitigate slow logger change with zap.AtomicLevel

zap provides possibility to change loglevel on the fly[1]. Use it to change loglevel of existing logger before the new reconfigured is taken in use. [1] https://github.com/uber-go/zap/blob/384e78230aefc7e724a1c9f526b9ab529f390983/level.go#L62 Signed-off-by: Yauheni Kaliuta <[email protected]>
opendatahub-io · Oct 4, 2024 · dd12452 · dd12452
1 parent 282e504
commit dd12452
Show file tree

Hide file tree

Showing 3 changed files with 47 additions and 24 deletions.
diff --git a/controllers/dscinitialization/dscinitialization_controller.go b/controllers/dscinitialization/dscinitialization_controller.go
@@ -103,7 +103,7 @@ func (r *DSCInitializationReconciler) Reconcile(ctx context.Context, req ctrl.Re
 		logmode := instance.Spec.DevFlags.LogMode
 		if logmode != "" { // allow override with explicit values only
 			log.V(1).Info("Setting logger mode", "mode", logmode)
-			logger.SetBaseLogger(logger.NewLogger(logmode))
+			logger.NewBaseLogger(logmode)
 		}
 	}
 

diff --git a/main.go b/main.go
@@ -142,9 +142,7 @@ func main() { //nolint:funlen,maintidx
 
 	flag.Parse()
 
-	l := logger.NewLogger(logmode)
-	ctrl.SetLogger(l)
-	logger.SetBaseLogger(l)
+	ctrl.SetLogger(logger.NewBaseLogger(logmode))
 
 	// root context
 	ctx := ctrl.SetupSignalHandler()

diff --git a/pkg/logger/logger.go b/pkg/logger/logger.go
@@ -5,12 +5,17 @@ import (
 	"sync/atomic"
 
 	"github.com/go-logr/logr"
+	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
-	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+	ctrlzap "sigs.k8s.io/controller-runtime/pkg/log/zap"
 	"sigs.k8s.io/controller-runtime/pkg/reconcile"
 )
 
-var baseLogger atomic.Value
+var (
+	baseLogger      atomic.Value
+	level           = zap.NewAtomicLevel()
+	stackTraceLevel = zap.NewAtomicLevel()
+)
 
 func NewLogConstructor(name string) func(req *reconcile.Request) logr.Logger {
 	return func(req *reconcile.Request) logr.Logger {
@@ -22,6 +27,13 @@ func NewLogConstructor(name string) func(req *reconcile.Request) logr.Logger {
 	}
 }
 
+func NewBaseLogger(mode string) logr.Logger {
+	l := NewLogger(mode)
+	SetLoggerLevel(mode)
+	SetBaseLogger(l)
+	return l
+}
+
 func SetBaseLogger(log logr.Logger) {
 	baseLogger.Store(log)
 }
@@ -31,25 +43,36 @@ func GetBaseLogger() logr.Logger {
 	return l
 }
 
+func SetLoggerLevel(mode string) {
+	switch mode {
+	case "devel", "development":
+		level.SetLevel(zapcore.DebugLevel)
+		stackTraceLevel.SetLevel(zapcore.WarnLevel)
+	case "prod", "production":
+		level.SetLevel(zapcore.ErrorLevel)
+		stackTraceLevel.SetLevel(zapcore.ErrorLevel)
+	default:
+		level.SetLevel(zapcore.InfoLevel)
+		stackTraceLevel.SetLevel(zapcore.ErrorLevel)
+	}
+}
+
 // in DSC component, to use different mode for logging, e.g. development, production
 // when not set mode it falls to "default" which is used by startup main.go.
 func NewLogger(mode string) logr.Logger {
-	var opts zap.Options
+	var opts ctrlzap.Options
+
 	switch mode {
 	case "devel", "development": //  the most logging verbosity
-		opts = zap.Options{
-			Development:     true,
-			StacktraceLevel: zapcore.WarnLevel,
-			Level:           zapcore.DebugLevel,
-			DestWriter:      os.Stdout,
+		opts = ctrlzap.Options{
+			Development: true,
+			DestWriter:  os.Stdout,
 		}
 	case "prod", "production": // the least logging verbosity
-		opts = zap.Options{
-			Development:     false,
-			StacktraceLevel: zapcore.ErrorLevel,
-			Level:           zapcore.ErrorLevel,
-			DestWriter:      os.Stdout,
-			EncoderConfigOptions: []zap.EncoderConfigOption{func(config *zapcore.EncoderConfig) {
+		opts = ctrlzap.Options{
+			Development: false,
+			DestWriter:  os.Stdout,
+			EncoderConfigOptions: []ctrlzap.EncoderConfigOption{func(config *zapcore.EncoderConfig) {
 				config.EncodeTime = zapcore.ISO8601TimeEncoder // human readable not epoch
 				config.EncodeDuration = zapcore.SecondsDurationEncoder
 				config.LevelKey = "LogLevel"
@@ -61,12 +84,14 @@ func NewLogger(mode string) logr.Logger {
 			}},
 		}
 	default:
-		opts = zap.Options{
-			Development:     false,
-			StacktraceLevel: zapcore.ErrorLevel,
-			Level:           zapcore.InfoLevel,
-			DestWriter:      os.Stdout,
+		opts = ctrlzap.Options{
+			Development: false,
+			DestWriter:  os.Stdout,
 		}
 	}
-	return zap.New(zap.UseFlagOptions(&opts))
+
+	opts.Level = level
+	opts.StacktraceLevel = stackTraceLevel
+
+	return ctrlzap.New(ctrlzap.UseFlagOptions(&opts))
 }