Improve common logging to allow the use of AtomicLevel (#15999)

* add new New method

* add missing comments

common/logging/logger/logger.go

@@ -17,12 +17,31 @@ type Logger struct {
 	zapLogger *zap.SugaredLogger
 }
 
+/*
+This function creates logger structure based on given format, atomicLevel and additional cores
+AtomicLevel structure allows to change level dynamically
+*/
+func NewWithAtomicLevel(format Format, atomicLevel zap.AtomicLevel, additionalCores ...zapcore.Core) (*Logger, error) {
+	return new(format, atomicLevel, additionalCores...)
+}
+
+/*
+This function creates logger structure based on given format, level and additional cores
+*/
 func New(format Format, level Level, additionalCores ...zapcore.Core) (*Logger, error) {
 	filterLevel, err := level.ToZapLevel()
 	if err != nil {
 		return nil, errors.Wrap(err, "while getting zap log level")
 	}
 
+	levelEnabler := zap.LevelEnablerFunc(func(incomingLevel zapcore.Level) bool {
+		return incomingLevel >= filterLevel
+	})
+
+	return new(format, levelEnabler, additionalCores...)
+}
+
+func new(format Format, levelEnabler zapcore.LevelEnabler, additionalCores ...zapcore.Core) (*Logger, error) {
 	encoder, err := format.ToZapEncoder()
 	if err != nil {
 		return nil, errors.Wrapf(err, "while getting encoding configuration  for %s format", format)
@@ -31,9 +50,7 @@ func New(format Format, level Level, additionalCores ...zapcore.Core) (*Logger,
 	defaultCore := zapcore.NewCore(
 		encoder,
 		zapcore.Lock(os.Stderr),
-		zap.LevelEnablerFunc(func(incomingLevel zapcore.Level) bool {
-			return incomingLevel >= filterLevel
-		}),
+		levelEnabler,
 	)
 	cores := append(additionalCores, defaultCore)
 	return &Logger{zap.New(zapcore.NewTee(cores...), zap.AddCaller()).Sugar()}, nil
@@ -53,7 +70,6 @@ func (l *Logger) WithContext() *zap.SugaredLogger {
 }
 
 /*
-*
 By default the Fatal Error log will be in json format, because it's production default.
 */
 func LogFatalError(format string, args ...interface{}) error {
@@ -66,7 +82,6 @@ func LogFatalError(format string, args ...interface{}) error {
 }
 
 /*
-*
 This function initialize klog which is used in k8s/go-client
 */
 func InitKlog(log *Logger, level Level) error {

common/logging/logger/logger_test.go

@@ -14,6 +14,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 	"go.uber.org/zap/zaptest/observer"
 )
 
@@ -43,6 +44,26 @@ func TestLogger(t *testing.T) {
 		t.Log(observedLogs.All())
 	})
 
+	t.Run("should log debug log after changing atomic level", func(t *testing.T) {
+		// given
+		atomic := zap.NewAtomicLevel()
+		atomic.SetLevel(zapcore.WarnLevel)
+		core, observedLogs := observer.New(atomic)
+		log, err := logger.NewWithAtomicLevel(logger.JSON, atomic, core)
+		require.NoError(t, err)
+		zapLogger := log.WithContext()
+
+		// when
+		zapLogger.Info("log anything")
+		require.Equal(t, 0, observedLogs.Len())
+
+		atomic.SetLevel(zapcore.InfoLevel)
+		zapLogger.Info("log anything 2")
+
+		// then
+		require.Equal(t, 1, observedLogs.Len())
+	})
+
 	t.Run("should log in the right json format", func(t *testing.T) {
 		// GIVEN
 		oldStdErr := os.Stderr