From d52d8dda07cdbb96f5c4ebf70435157ca6fd6a92 Mon Sep 17 00:00:00 2001
From: Marc Magnin <marc.magnin@digitalis.io>
Date: Thu, 8 Feb 2018 11:13:50 +0100
Subject: [PATCH] #17 Enable use of MQTT broker as a library -> passing a
 logger reference to the broker instance

---
 broker/broker.go      |  3 ++-
 logger/logger.go      | 33 +++++++++++++++------------------
 logger/logger_test.go | 12 ++++--------
 main.go               |  5 +++--
 4 files changed, 24 insertions(+), 29 deletions(-)

diff --git a/broker/broker.go b/broker/broker.go
index 3045c8c..4e07175 100644
--- a/broker/broker.go
+++ b/broker/broker.go
@@ -47,7 +47,8 @@ type Broker struct {
 	queues     map[string]int
 }
 
-func NewBroker(config *Config) (*Broker, error) {
+func NewBroker(config *Config, logger *zap.Logger) (*Broker, error) {
+	log = logger
 	b := &Broker{
 		id:         GenUniqueId(),
 		config:     config,
diff --git a/logger/logger.go b/logger/logger.go
index d3c72e8..4bcfddd 100644
--- a/logger/logger.go
+++ b/logger/logger.go
@@ -8,43 +8,40 @@ import (
 )
 
 var (
-	// env can be setup at build time with Go Linker. Value could be prod or whatever else for dev env
-	instance *zap.Logger
-	logCfg   zap.Config
+	logInstance *zap.Logger
 )
 
-// NewDevLogger return a logger for dev builds
-func NewDevLogger() (*zap.Logger, error) {
+// InitDevLogger instanciate a logger for dev builds
+func InitDevLogger() {
 	logCfg := zap.NewDevelopmentConfig()
-	return logCfg.Build()
+	logInstance, _ = logCfg.Build()
 }
 
-// NewProdLogger return a logger for production builds
-func NewProdLogger() (*zap.Logger, error) {
+// InitProdLogger instanciate a logger for production builds
+func InitProdLogger() {
 	logCfg := zap.NewProductionConfig()
 	logCfg.DisableStacktrace = true
 	logCfg.Level = zap.NewAtomicLevelAt(zap.InfoLevel)
-	return logCfg.Build()
+	logInstance, _ = logCfg.Build()
 }
 
 func InitLogger(debug bool) {
 	var err error
-	var log *zap.Logger
 	if debug {
-		log, err = NewDevLogger()
+		InitDevLogger()
 	} else {
-		log, err = NewProdLogger()
+		InitProdLogger()
 	}
 	if err != nil {
 		panic("Unable to create a logger.")
 	}
-	defer log.Sync()
-
-	log.Debug("Logger initialization succeeded")
-	instance = log.Named("hmq")
+	logInstance.Debug("Logger initialization succeeded")
 }
 
-// Get return a *zap.Logger instance
+// Get the existing *zap.Logger instance. If none have been created, it'll instanciate de dev logger
 func Get() *zap.Logger {
-	return instance
+	if logInstance == nil {
+		InitDevLogger()
+	}
+	return logInstance
 }
diff --git a/logger/logger_test.go b/logger/logger_test.go
index c1291d4..d419133 100644
--- a/logger/logger_test.go
+++ b/logger/logger_test.go
@@ -19,15 +19,11 @@ func TestGet(t *testing.T) {
 }
 
 func TestNewDevLogger(t *testing.T) {
-	logger, err := NewDevLogger()
-
-	assert.Nil(t, err)
-	assert.True(t, logger.Core().Enabled(zap.DebugLevel))
+	InitDevLogger()
+	assert.True(t, Get().Core().Enabled(zap.DebugLevel))
 }
 
 func TestNewProdLogger(t *testing.T) {
-	logger, err := NewProdLogger()
-
-	assert.Nil(t, err)
-	assert.False(t, logger.Core().Enabled(zap.DebugLevel))
+	InitProdLogger()
+	assert.False(t, Get().Core().Enabled(zap.DebugLevel))
 }
diff --git a/main.go b/main.go
index 0062ff6..c4dd603 100644
--- a/main.go
+++ b/main.go
@@ -13,6 +13,7 @@ import (
 	"runtime"
 
 	"github.com/fhmq/hmq/broker"
+	"github.com/fhmq/hmq/logger"
 )
 
 func main() {
@@ -22,8 +23,8 @@ func main() {
 		fmt.Println("configure broker config error: ", err)
 		return
 	}
-
-	b, err := broker.NewBroker(config)
+	logger.InitLogger(config.Debug)
+	b, err := broker.NewBroker(config, logger.Get())
 	if err != nil {
 		fmt.Println("New Broker error: ", err)
 		return