Implement Jaeger-client Logger with go-kit level logger (#25)

client/log/go-kit/logger.go

@@ -0,0 +1,64 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package xkit
+
+import (
+	"fmt"
+
+	"github.com/go-kit/kit/log"
+	"github.com/go-kit/kit/log/level"
+)
+
+// LoggerOption sets a parameter for the Logger.
+type LoggerOption func(*Logger)
+
+// MessageKey sets the key for the actual log message. By default, it's "msg".
+func MessageKey(key string) LoggerOption {
+	return func(l *Logger) { l.messageKey = key }
+}
+
+// Logger wraps a go-kit logger instance in a Jaeger client compatible one.
+type Logger struct {
+	infoLogger  log.Logger
+	errorLogger log.Logger
+
+	messageKey string
+}
+
+// NewLogger creates a new Jaeger client logger from a go-kit one.
+func NewLogger(kitlogger log.Logger, options ...LoggerOption) *Logger {
+	logger := &Logger{
+		infoLogger:  level.Info(kitlogger),
+		errorLogger: level.Error(kitlogger),
+
+		messageKey: "msg",
+	}
+
+	for _, option := range options {
+		option(logger)
+	}
+
+	return logger
+}
+
+// Error implements the github.com/uber/jaeger-client-go/log.Logger interface.
+func (l *Logger) Error(msg string) {
+	l.errorLogger.Log(l.messageKey, msg)
+}
+
+// Infof implements the github.com/uber/jaeger-client-go/log.Logger interface.
+func (l *Logger) Infof(msg string, args ...interface{}) {
+	l.infoLogger.Log(l.messageKey, fmt.Sprintf(msg, args...))
+}

client/log/go-kit/logger_test.go

@@ -0,0 +1,36 @@
+package xkit
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/go-kit/kit/log"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLogger_Infof(t *testing.T) {
+	buf := &bytes.Buffer{}
+	logger := NewLogger(log.NewLogfmtLogger(buf))
+
+	logger.Infof("Formatted %s", "string")
+
+	assert.Equal(t, "level=info msg=\"Formatted string\"\n", buf.String())
+}
+
+func TestLogger_Error(t *testing.T) {
+	buf := &bytes.Buffer{}
+	logger := NewLogger(log.NewLogfmtLogger(buf))
+
+	logger.Error("Something really bad happened")
+
+	assert.Equal(t, "level=error msg=\"Something really bad happened\"\n", buf.String())
+}
+
+func TestMessageKey(t *testing.T) {
+	buf := &bytes.Buffer{}
+	logger := NewLogger(log.NewLogfmtLogger(buf), MessageKey("message"))
+
+	logger.Error("Something really bad happened")
+
+	assert.Equal(t, "level=error message=\"Something really bad happened\"\n", buf.String())
+}