Merge pull request #1049 from micro/kubernetes-logging

Kubernetes logging

debug/log/kubernetes/kubernetes.go

@@ -0,0 +1,27 @@
+// Package kubernetes is a logger implementing (github.com/micro/go-micro/debug/log).Log
+package kubernetes
+
+import (
+	"errors"
+
+	"github.com/micro/go-micro/debug/log"
+)
+
+type klog struct{}
+
+func (k *klog) Read(...log.ReadOption) ([]log.Record, error) {
+	return nil, errors.New("not implemented")
+}
+
+func (k *klog) Write(l log.Record) error {
+	return write(l)
+}
+
+func (k *klog) Stream() (log.Stream, error) {
+	return &klogStreamer{}, nil
+}
+
+// New returns a configured Kubernetes logger
+func New() log.Log {
+	return &klog{}
+}

debug/log/kubernetes/kubernetes_test.go

@@ -0,0 +1,56 @@
+package kubernetes
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/micro/go-micro/debug/log"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestKubernetes(t *testing.T) {
+	k := New()
+
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := os.Stderr
+	os.Stderr = w
+	meta := make(map[string]string)
+	write := log.Record{
+		Timestamp: time.Unix(0, 0).UTC(),
+		Value:     "Test log entry",
+		Metadata:  meta,
+	}
+	meta["foo"] = "bar"
+	k.Write(write)
+	b := &bytes.Buffer{}
+	w.Close()
+	io.Copy(b, r)
+	os.Stderr = s
+	var read log.Record
+	if err := json.Unmarshal(b.Bytes(), &read); err != nil {
+		t.Fatalf("json.Unmarshal failed: %s", err.Error())
+	}
+	assert.Equal(t, write, read, "Write was not equal")
+
+	_, err = k.Read()
+	assert.Error(t, err, "Read should be unimplemented")
+
+	stream, err := k.Stream()
+	if err != nil {
+		t.Error(err)
+	}
+	records := []log.Record{}
+	go stream.Stop()
+	for s := range stream.Chan() {
+		records = append(records, s)
+	}
+	assert.Equal(t, 0, len(records), "Stream should return nothing")
+
+}

debug/log/kubernetes/log.go

@@ -0,0 +1,34 @@
+package kubernetes
+
+import "github.com/micro/go-micro/debug/log"
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+)
+
+func write(l log.Record) error {
+	m, err := json.Marshal(l)
+	if err == nil {
+		_, err := fmt.Fprintf(os.Stderr, "%s", m)
+		return err
+	}
+	return err
+}
+
+type klogStreamer struct {
+	streamChan chan log.Record
+}
+
+func (k *klogStreamer) Chan() <-chan log.Record {
+	if k.streamChan == nil {
+		k.streamChan = make(chan log.Record)
+	}
+	return k.streamChan
+}
+
+func (k *klogStreamer) Stop() error {
+	close(k.streamChan)
+	return nil
+}

debug/log/log.go

@@ -27,11 +27,11 @@ type Log interface {
 // Record is log record entry
 type Record struct {
 	// Timestamp of logged event
-	Timestamp time.Time
+	Timestamp time.Time `json:"time"`
 	// Value contains log entry
-	Value interface{}
+	Value interface{} `json:"value"`
 	// Metadata to enrich log record
-	Metadata map[string]string
+	Metadata map[string]string `json:"metadata"`
 }
 
 type Stream interface {