Refactoring: implement proper JSON logging, better structure for app layers

pkg/infrastructure/jsonlog/level.go

@@ -0,0 +1,13 @@
+package jsonlog
+
+import "github.com/sirupsen/logrus"
+
+type Level logrus.Level
+
+const (
+	FatalLevel = Level(logrus.FatalLevel)
+	ErrorLevel = Level(logrus.ErrorLevel)
+	WarnLevel  = Level(logrus.WarnLevel)
+	InfoLevel  = Level(logrus.InfoLevel)
+	DebugLevel = Level(logrus.DebugLevel)
+)

pkg/infrastructure/jsonlog/logger.go

@@ -0,0 +1,49 @@
+package jsonlog
+
+import (
+	"time"
+
+	"github.com/sirupsen/logrus"
+)
+
+const appNameKey = "app_name"
+
+var fieldMap = logrus.FieldMap{
+	logrus.FieldKeyTime: "@timestamp",
+	logrus.FieldKeyMsg:  "message",
+}
+
+type Logger interface {
+	Info(...interface{})
+	Error(error, ...interface{})
+	FatalError(error, ...interface{})
+}
+
+type Config struct {
+	AppName string
+	Level   Level
+}
+
+func NewLogger(config *Config) Logger {
+	impl := logrus.New()
+	impl.SetFormatter(&logrus.JSONFormatter{
+		TimestampFormat: time.RFC3339Nano,
+		FieldMap:        fieldMap,
+	})
+	impl.SetLevel(logrus.Level(config.Level))
+	return &logger{
+		FieldLogger: impl.WithField(appNameKey, config.AppName),
+	}
+}
+
+type logger struct {
+	logrus.FieldLogger
+}
+
+func (l *logger) Error(err error, args ...interface{}) {
+	l.FieldLogger.WithError(err).Error(args)
+}
+
+func (l *logger) FatalError(err error, args ...interface{}) {
+	l.FieldLogger.WithError(err).Fatal(args...)
+}