Add interface to the Logger

container/container.go

@@ -10,20 +10,20 @@ import (
 type Container interface {
 	GetRepository() repository.Repository
 	GetConfig() *config.Config
-	GetLogger() *logger.Logger
+	GetLogger() logger.Logger
 	GetEnv() string
 }
 
 // container struct is for sharing data which such as database setting, the setting of application and logger in overall this application.
 type container struct {
 	rep    repository.Repository
 	config *config.Config
-	logger *logger.Logger
+	logger logger.Logger
 	env    string
 }
 
 // NewContainer is constructor.
-func NewContainer(rep repository.Repository, config *config.Config, logger *logger.Logger, env string) Container {
+func NewContainer(rep repository.Repository, config *config.Config, logger logger.Logger, env string) Container {
 	return &container{rep: rep, config: config, logger: logger, env: env}
 }
 
@@ -38,7 +38,7 @@ func (c *container) GetConfig() *config.Config {
 }
 
 // GetLogger returns the object of logger.
-func (c *container) GetLogger() *logger.Logger {
+func (c *container) GetLogger() logger.Logger {
 	return c.logger
 }
 

logger/gormlogger.go

@@ -22,39 +22,39 @@ const (
 )
 
 // LogMode: The log level of gorm logger is overwrited by the log level of Zap logger.
-func (l *Logger) LogMode(level gormLogger.LogLevel) gormLogger.Interface {
+func (l *logger) LogMode(level gormLogger.LogLevel) gormLogger.Interface {
 	return l
 }
 
 // Info prints a information log.
-func (l *Logger) Info(ctx context.Context, msg string, data ...interface{}) {
+func (l *logger) Info(ctx context.Context, msg string, data ...interface{}) {
 	l.Zap.Infof(messageFormat, append([]interface{}{msg, gormUtils.FileWithLineNum()}, data...)...)
 }
 
 // Warn prints a warning log.
-func (l *Logger) Warn(ctx context.Context, msg string, data ...interface{}) {
+func (l *logger) Warn(ctx context.Context, msg string, data ...interface{}) {
 	l.Zap.Warnf(messageFormat, append([]interface{}{msg, gormUtils.FileWithLineNum()}, data...)...)
 }
 
 // Error prints a error log.
-func (l *Logger) Error(ctx context.Context, msg string, data ...interface{}) {
+func (l *logger) Error(ctx context.Context, msg string, data ...interface{}) {
 	l.Zap.Errorf(messageFormat, append([]interface{}{msg, gormUtils.FileWithLineNum()}, data...)...)
 }
 
 // Trace prints a trace log such as sql, source file and error.
-func (l *Logger) Trace(ctx context.Context, begin time.Time, fc func() (string, int64), err error) {
+func (l *logger) Trace(ctx context.Context, begin time.Time, fc func() (string, int64), err error) {
 	elapsed := time.Since(begin)
 
 	switch {
 	case err != nil:
 		sql, _ := fc()
-		l.Zap.Errorf(errorFormat, gormUtils.FileWithLineNum(), err, sql)
+		l.GetZapLogger().Errorf(errorFormat, gormUtils.FileWithLineNum(), err, sql)
 	case elapsed > slowThreshold*time.Millisecond && slowThreshold*time.Millisecond != 0:
 		sql, _ := fc()
 		slowLog := fmt.Sprintf("SLOW SQL >= %v", slowThreshold)
-		l.Zap.Warnf(errorFormat, gormUtils.FileWithLineNum(), slowLog, sql)
+		l.GetZapLogger().Warnf(errorFormat, gormUtils.FileWithLineNum(), slowLog, sql)
 	default:
 		sql, _ := fc()
-		l.Zap.Debugf(sqlFormat, sql)
+		l.GetZapLogger().Debugf(sqlFormat, sql)
 	}
 }

logger/logger.go

@@ -1,13 +1,16 @@
 package logger
 
 import (
+	"context"
 	"fmt"
 	"io/ioutil"
 	"os"
+	"time"
 
 	"go.uber.org/zap"
 	"gopkg.in/natefinch/lumberjack.v2"
 	"gopkg.in/yaml.v2"
+	gormLogger "gorm.io/gorm/logger"
 )
 
 // Config represents the setting for zap logger.
@@ -17,12 +20,26 @@ type Config struct {
 }
 
 // Logger is an alternative implementation of *gorm.Logger
-type Logger struct {
+type Logger interface {
+	GetZapLogger() *zap.SugaredLogger
+	LogMode(level gormLogger.LogLevel) gormLogger.Interface
+	Info(ctx context.Context, msg string, data ...interface{})
+	Warn(ctx context.Context, msg string, data ...interface{})
+	Error(ctx context.Context, msg string, data ...interface{})
+	Trace(ctx context.Context, begin time.Time, fc func() (string, int64), err error)
+}
+
+type logger struct {
 	Zap *zap.SugaredLogger
 }
 
-// NewLogger create logger object for *gorm.DB from *echo.Logger
-func NewLogger(env string) *Logger {
+// NewLogger is constructor for logger
+func NewLogger(sugar *zap.SugaredLogger) Logger {
+	return &logger{Zap: sugar}
+}
+
+// InitLogger create logger object for *gorm.DB from *echo.Logger
+func InitLogger(env string) Logger {
 	configYaml, err := ioutil.ReadFile("./zaplogger." + env + ".yml")
 	if err != nil {
 		fmt.Printf("Failed to read logger configuration: %s", err)
@@ -41,13 +58,13 @@ func NewLogger(env string) *Logger {
 	}
 	sugar := zap.Sugar()
 	// set package varriable logger.
-	logger := &Logger{Zap: sugar}
-	logger.Zap.Infof("Success to read zap logger configuration: zaplogger." + env + ".yml")
+	log := NewLogger(sugar)
+	log.GetZapLogger().Infof("Success to read zap logger configuration: zaplogger." + env + ".yml")
 	_ = zap.Sync()
-	return logger
+	return log
 }
 
 // GetZapLogger returns zapSugaredLogger
-func (log *Logger) GetZapLogger() *zap.SugaredLogger {
+func (log *logger) GetZapLogger() *zap.SugaredLogger {
 	return log.Zap
 }

main.go

@@ -24,7 +24,7 @@ func main() {
 	e := echo.New()
 
 	conf, env := config.Load()
-	logger := logger.NewLogger(env)
+	logger := logger.InitLogger(env)
 	logger.GetZapLogger().Infof("Loaded this configuration : application." + env + ".yml")
 
 	rep := repository.NewBookRepository(logger, conf)

repository/repository.go

@@ -46,7 +46,7 @@ type bookRepository struct {
 }
 
 // NewBookRepository is constructor for bookRepository.
-func NewBookRepository(logger *logger.Logger, conf *config.Config) Repository {
+func NewBookRepository(logger logger.Logger, conf *config.Config) Repository {
 	logger.GetZapLogger().Infof("Try database connection")
 	db, err := connectDatabase(logger, conf)
 	if err != nil {
@@ -66,7 +66,7 @@ const (
 	MYSQL = "mysql"
 )
 
-func connectDatabase(logger *logger.Logger, config *config.Config) (*gorm.DB, error) {
+func connectDatabase(logger logger.Logger, config *config.Config) (*gorm.DB, error) {
 	var dsn string
 	gormConfig := &gorm.Config{Logger: logger}
 

test/unittest_util.go

@@ -75,32 +75,32 @@ func createConfig(isSecurity bool) *config.Config {
 	return conf
 }
 
-func initContainer(conf *config.Config, logger *logger.Logger) container.Container {
+func initContainer(conf *config.Config, logger logger.Logger) container.Container {
 	rep := repository.NewBookRepository(logger, conf)
 	container := container.NewContainer(rep, conf, logger, "test")
 	return container
 }
 
-func initTestLogger() *logger.Logger {
+func initTestLogger() logger.Logger {
 	myConfig := createLoggerConfig()
 	zap, err := myConfig.Build()
 	if err != nil {
 		fmt.Printf("Error")
 	}
 	sugar := zap.Sugar()
 	// set package varriable logger.
-	logger := &logger.Logger{Zap: sugar}
+	logger := logger.NewLogger(sugar)
 	logger.GetZapLogger().Infof("Success to read zap logger configuration")
 	_ = zap.Sync()
 	return logger
 }
 
-func initObservedLogger() (*logger.Logger, *observer.ObservedLogs) {
+func initObservedLogger() (logger.Logger, *observer.ObservedLogs) {
 	observedZapCore, observedLogs := observer.New(zap.DebugLevel)
 	sugar := zap.New(observedZapCore).Sugar()
 
 	// set package varriable logger.
-	logger := &logger.Logger{Zap: sugar}
+	logger := logger.NewLogger(sugar)
 	return logger, observedLogs
 }