Added license and updated alternative backends

Author: Lars Ekman

pkg/log/logger.go

@@ -1,3 +1,19 @@
+/*
+Copyright (c) 2022 Nordix Foundation
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 package log
 
 import (
@@ -6,7 +22,24 @@ import (
 	"github.com/go-logr/logr"
 )
 
+// Several different logr backends can be tested by remove/add comment
+// below.
+
 /*
+// This does not work! (doesn't even compile)
+import (
+	"k8s.io/klog/klogr"
+)
+func newLogger(level string) logr.Logger {
+	return klogr.New()
+}
+func init() {
+	defaultLogger = newLogger("").WithName("Meridio")
+}
+*/
+
+/*
+// Zerologr doesn't implement logger.Enabled() correctly
 import (
     "os"
     "github.com/go-logr/zerologr"
@@ -30,6 +63,9 @@ func newLogger(level string) logr.Logger {
     zl = zl.With().Timestamp().Logger().Level(lvl)
     return zerologr.New(&zl)
 }
+func init() {
+	defaultLogger = newLogger("").WithName("Meridio")
+}
 */
 
 /*
@@ -59,6 +95,9 @@ func newLogger(level string) logr.Logger {
     return zapr.NewLogger(z)
 
 }
+func init() {
+	defaultLogger = newLogger("").WithName("Meridio")
+}
 */
 
 /*
@@ -82,6 +121,9 @@ func newLogger(level string) logr.Logger {
 	logrusLog.SetLevel(lvl)
     return logrusr.New(logrusLog)
 }
+func init() {
+	defaultLogger = newLogger("").WithName("Meridio")
+}
 */
 
 import (
@@ -265,8 +307,6 @@ func (e *adpEncoder) OpenNamespace(key string) {
 	e.jsonEncoder.OpenNamespace(key)
 }
 
-var defaultLogger logr.Logger
-
 func init() {
 	_ = zap.RegisterEncoder(
 		"ADP", func(cfg zapcore.EncoderConfig) (zapcore.Encoder, error) {
@@ -278,16 +318,6 @@ func init() {
 	defaultLogger = newLogger("").WithName("Meridio")
 }
 
-// FromContextOrDefault return a logger from the passed context or a
-// default logger. This function is intended as a temprary solution
-// during the transition to structured logging.
-func FromContextOrDefault(ctx context.Context) logr.Logger {
-	if logger, err := logr.FromContext(ctx); err == nil {
-		return logger
-	}
-	return defaultLogger
-}
-
 // Fatal log the message using the passed logger and terminate
 func Fatal(logger logr.Logger, msg string, keysAndValues ...interface{}) {
 	// Get the zap logger
@@ -300,6 +330,18 @@ func Fatal(logger logr.Logger, msg string, keysAndValues ...interface{}) {
 	}
 }
 
+var defaultLogger logr.Logger
+
+// FromContextOrDefault return a logger from the passed context or a
+// default logger. This function is intended as a temprary solution
+// during the transition to structured logging.
+func FromContextOrDefault(ctx context.Context) logr.Logger {
+	if logger, err := logr.FromContext(ctx); err == nil {
+		return logger
+	}
+	return defaultLogger
+}
+
 // New returns a new logger. The level may be "DEBUG" (V(1)) or "TRACE" (V(2)),
 // any other string (e.g. "") is interpreted as "INFO" (V(0)).
 func New(name, level string) logr.Logger {