Add options for customizing threadiness, logger encoding, and global logger level

cmd/flagger/main.go

@@ -31,6 +31,7 @@ var (
 	slackURL            string
 	slackUser           string
 	slackChannel        string
+	threadiness         int
 )
 
 func init() {
@@ -43,6 +44,7 @@ func init() {
 	flag.StringVar(&slackURL, "slack-url", "", "Slack hook URL.")
 	flag.StringVar(&slackUser, "slack-user", "flagger", "Slack user name.")
 	flag.StringVar(&slackChannel, "slack-channel", "", "Slack channel.")
+	flag.IntVar(&threadiness, "threadiness", 2, "Worker concurrency.")
 }
 
 func main() {
@@ -52,6 +54,7 @@ func main() {
 	if err != nil {
 		log.Fatalf("Error creating logger: %v", err)
 	}
+	logging.ReplaceGlobalIf(logger.Desugar())
 	defer logger.Sync()
 
 	stopCh := signals.SetupSignalHandler()
@@ -132,7 +135,7 @@ func main() {
 
 	// start controller
 	go func(ctrl *controller.Controller) {
-		if err := ctrl.Run(2, stopCh); err != nil {
+		if err := ctrl.Run(threadiness, stopCh); err != nil {
 			logger.Fatalf("Error running controller: %v", err)
 		}
 	}(c)

pkg/logging/logger.go

@@ -1,6 +1,7 @@
 package logging
 
 import (
+	"flag"
 	"fmt"
 	"os"
 
@@ -8,6 +9,17 @@ import (
 	"go.uber.org/zap/zapcore"
 )
 
+var (
+	replaceGlobals bool
+	encoding       string
+)
+
+func init() {
+	flag.BoolVar(&replaceGlobals, "zap-replace-globals", false, "Whether to change level of global zap logger.")
+	flag.StringVar(&encoding, "zap-encoding", "json", "Zap logger encoding.")
+
+}
+
 // NewLogger returns a zap sugared logger configured with json format and caller id
 func NewLogger(logLevel string) (*zap.SugaredLogger, error) {
 	level := zap.NewAtomicLevelAt(zapcore.InfoLevel)
@@ -47,7 +59,7 @@ func NewLogger(logLevel string) (*zap.SugaredLogger, error) {
 			Initial:    100,
 			Thereafter: 100,
 		},
-		Encoding:         "json",
+		Encoding:         encoding,
 		EncoderConfig:    zapEncoderConfig,
 		OutputPaths:      []string{"stderr"},
 		ErrorOutputPaths: []string{"stderr"},
@@ -60,6 +72,12 @@ func NewLogger(logLevel string) (*zap.SugaredLogger, error) {
 	return logger.Sugar(), nil
 }
 
+func ReplaceGlobalIf(logger *zap.Logger) {
+	if replaceGlobals {
+		zap.ReplaceGlobals(logger)
+	}
+}
+
 // Console writes to stdout if the console env var exists
 func Console(a ...interface{}) (n int, err error) {
 	if os.Getenv("console") != "" {