Global logger (#2265)

* global logger

* return global logger appliance instead of inner logger

* fix lint issues

* global logger test

log/global.go

@@ -27,8 +27,8 @@ func (a *loggerAppliance) SetLogger(in Logger) {
 	a.Logger = in
 }
 
-func (a *loggerAppliance) GetLogger() Logger {
-	return a.Logger
+func (a *loggerAppliance) Log(level Level, keyvals ...interface{}) error {
+	return a.Logger.Log(level, keyvals...)
 }
 
 // SetLogger should be called before any other log call.
@@ -39,7 +39,7 @@ func SetLogger(logger Logger) {
 
 // GetLogger returns global logger appliance as logger in current process.
 func GetLogger() Logger {
-	return global.GetLogger()
+	return global
 }
 
 // Log Print log by level and keyvals.

log/global_test.go

@@ -14,7 +14,7 @@ func TestGlobalLog(t *testing.T) {
 	logger := NewStdLogger(buffer)
 	SetLogger(logger)
 
-	if GetLogger() != logger {
+	if global.Logger != logger {
 		t.Error("GetLogger() is not equal to logger")
 	}