Setup production logging

For production the log format is JSON, the timestamps format is ISO8601
and stack traces are logged when the level is set to debug.

config/manager/deployment.yaml

@@ -39,6 +39,7 @@ spec:
             path: /metrics
         args:
         - --enable-leader-election
+        - --log-level=debug
         - --log-json
         resources:
           limits:

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/go-logr/logr v0.1.0
 	github.com/onsi/ginkgo v1.11.0
 	github.com/onsi/gomega v1.8.1
+	go.uber.org/zap v1.10.0
 	k8s.io/api v0.18.4
 	k8s.io/apimachinery v0.18.4
 	k8s.io/client-go v0.18.4

main.go

@@ -21,15 +21,19 @@ import (
 	"os"
 	"time"
 
-	kustomizev1 "github.com/fluxcd/kustomize-controller/api/v1alpha1"
+	"github.com/go-logr/logr"
-	"github.com/fluxcd/kustomize-controller/controllers"
+	uzap "go.uber.org/zap"
-	"github.com/fluxcd/pkg/recorder"
+	"go.uber.org/zap/zapcore"
-	sourcev1 "github.com/fluxcd/source-controller/api/v1alpha1"
 	"k8s.io/apimachinery/pkg/runtime"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+
+	kustomizev1 "github.com/fluxcd/kustomize-controller/api/v1alpha1"
+	"github.com/fluxcd/kustomize-controller/controllers"
+	"github.com/fluxcd/pkg/recorder"
+	sourcev1 "github.com/fluxcd/source-controller/api/v1alpha1"
 	// +kubebuilder:scaffold:imports
 )
 
@@ -53,6 +57,7 @@ func main() {
 		enableLeaderElection bool
 		concurrent           int
 		requeueDependency    time.Duration
+		logLevel             string
 		logJSON              bool
 	)
 
@@ -63,10 +68,11 @@ func main() {
 			"Enabling this will ensure there is only one active controller manager.")
 	flag.IntVar(&concurrent, "concurrent", 4, "The number of concurrent kustomize reconciles.")
 	flag.DurationVar(&requeueDependency, "requeue-dependency", 30*time.Second, "The interval at which failing dependencies are reevaluated.")
+	flag.StringVar(&logLevel, "log-level", "info", "Set logging level. Can be debug, info or error.")
 	flag.BoolVar(&logJSON, "log-json", false, "Set logging to JSON format.")
 	flag.Parse()
 
-	ctrl.SetLogger(zap.New(zap.UseDevMode(!logJSON)))
+	ctrl.SetLogger(newLogger(logLevel, logJSON))
 
 	var eventRecorder *recorder.EventRecorder
 	if eventsAddr != "" {
@@ -120,3 +126,29 @@ func main() {
 		os.Exit(1)
 	}
 }
+
+// newLogger returns a logger configured for dev or production use.
+// For production the log format is JSON, the timestamps format is ISO8601
+// and stack traces are logged when the level is set to debug.
+func newLogger(level string, production bool) logr.Logger {
+	if !production {
+		return zap.New(zap.UseDevMode(true))
+	}
+
+	encCfg := uzap.NewProductionEncoderConfig()
+	encCfg.EncodeTime = zapcore.ISO8601TimeEncoder
+	encoder := zap.Encoder(zapcore.NewJSONEncoder(encCfg))
+
+	logLevel := zap.Level(zapcore.InfoLevel)
+	stacktraceLevel := zap.StacktraceLevel(zapcore.PanicLevel)
+
+	switch level {
+	case "debug":
+		logLevel = zap.Level(zapcore.DebugLevel)
+		stacktraceLevel = zap.StacktraceLevel(zapcore.ErrorLevel)
+	case "error":
+		logLevel = zap.Level(zapcore.ErrorLevel)
+	}
+
+	return zap.New(encoder, logLevel, stacktraceLevel)
+}