Logging improvements

pkg/infrastructure/jsonlog/logger.go

@@ -14,6 +14,8 @@ var fieldMap = logrus.FieldMap{
 }
 
 type Logger interface {
+	WithField(key string, value interface{}) Logger
+
 	Info(...interface{})
 	Error(error, ...interface{})
 	FatalError(error, ...interface{})
@@ -40,6 +42,10 @@ type logger struct {
 	logrus.FieldLogger
 }
 
+func (l *logger) WithField(key string, value interface{}) Logger {
+	return &logger{l.FieldLogger.WithField(key, value)}
+}
+
 func (l *logger) Error(err error, args ...interface{}) {
 	l.FieldLogger.WithError(err).Error(args)
 }