pkg/logutil: add "NewJournaldWriter"

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

pkg/logutil/zap_grpc.go

@@ -15,8 +15,6 @@
 package logutil
 
 import (
-	"github.com/coreos/etcd/raft"
-
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 	"google.golang.org/grpc/grpclog"
@@ -102,65 +100,3 @@ func (zl *zapGRPCLogger) V(l int) bool {
 	}
 	return true
 }
-
-// NewRaftLogger converts "*zap.Logger" to "raft.Logger".
-func NewRaftLogger(lcfg zap.Config) (raft.Logger, error) {
-	lg, err := lcfg.Build(zap.AddCallerSkip(1)) // to annotate caller outside of "logutil"
-	if err != nil {
-		return nil, err
-	}
-	return &zapRaftLogger{lg: lg, sugar: lg.Sugar()}, nil
-}
-
-type zapRaftLogger struct {
-	lg    *zap.Logger
-	sugar *zap.SugaredLogger
-}
-
-func (zl *zapRaftLogger) Debug(args ...interface{}) {
-	zl.sugar.Debug(args...)
-}
-
-func (zl *zapRaftLogger) Debugf(format string, args ...interface{}) {
-	zl.sugar.Debugf(format, args...)
-}
-
-func (zl *zapRaftLogger) Error(args ...interface{}) {
-	zl.sugar.Error(args...)
-}
-
-func (zl *zapRaftLogger) Errorf(format string, args ...interface{}) {
-	zl.sugar.Errorf(format, args...)
-}
-
-func (zl *zapRaftLogger) Info(args ...interface{}) {
-	zl.sugar.Info(args...)
-}
-
-func (zl *zapRaftLogger) Infof(format string, args ...interface{}) {
-	zl.sugar.Infof(format, args...)
-}
-
-func (zl *zapRaftLogger) Warning(args ...interface{}) {
-	zl.sugar.Warn(args...)
-}
-
-func (zl *zapRaftLogger) Warningf(format string, args ...interface{}) {
-	zl.sugar.Warnf(format, args...)
-}
-
-func (zl *zapRaftLogger) Fatal(args ...interface{}) {
-	zl.sugar.Fatal(args...)
-}
-
-func (zl *zapRaftLogger) Fatalf(format string, args ...interface{}) {
-	zl.sugar.Fatalf(format, args...)
-}
-
-func (zl *zapRaftLogger) Panic(args ...interface{}) {
-	zl.sugar.Panic(args...)
-}
-
-func (zl *zapRaftLogger) Panicf(format string, args ...interface{}) {
-	zl.sugar.Panicf(format, args...)
-}

pkg/logutil/zap_grpc_test.go

@@ -66,50 +66,7 @@ func TestNewGRPCLoggerV2(t *testing.T) {
 	if !bytes.Contains(data, []byte("etcd-logutil-2")) {
 		t.Fatalf("can't find data in log %q", string(data))
 	}
-	if !bytes.Contains(data, []byte("logutil/zap_test.go:")) {
+	if !bytes.Contains(data, []byte("logutil/zap_grpc_test.go:")) {
-		t.Fatalf("unexpected caller; %q", string(data))
-	}
-}
-
-func TestNewRaftLogger(t *testing.T) {
-	logPath := filepath.Join(os.TempDir(), fmt.Sprintf("test-log-%d", time.Now().UnixNano()))
-	defer os.RemoveAll(logPath)
-
-	lcfg := zap.Config{
-		Level:       zap.NewAtomicLevelAt(zap.DebugLevel),
-		Development: false,
-		Sampling: &zap.SamplingConfig{
-			Initial:    100,
-			Thereafter: 100,
-		},
-		Encoding:         "json",
-		EncoderConfig:    zap.NewProductionEncoderConfig(),
-		OutputPaths:      []string{logPath},
-		ErrorOutputPaths: []string{logPath},
-	}
-	gl, err := NewRaftLogger(lcfg)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	gl.Info("etcd-logutil-1")
-	data, err := ioutil.ReadFile(logPath)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if !bytes.Contains(data, []byte("etcd-logutil-1")) {
-		t.Fatalf("can't find data in log %q", string(data))
-	}
-
-	gl.Warning("etcd-logutil-2")
-	data, err = ioutil.ReadFile(logPath)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if !bytes.Contains(data, []byte("etcd-logutil-2")) {
-		t.Fatalf("can't find data in log %q", string(data))
-	}
-	if !bytes.Contains(data, []byte("logutil/zap_test.go:")) {
 		t.Fatalf("unexpected caller; %q", string(data))
 	}
 }

pkg/logutil/zap_journald.go

@@ -0,0 +1,85 @@
+// Copyright 2018 The etcd Authors
+//
+// 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 logutil
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/coreos/go-systemd/journal"
+	"go.uber.org/zap/zapcore"
+)
+
+// NewJournaldWriter wraps "io.Writer" to redirect log output
+// to the local systemd journal. If journald send fails, it fails
+// back to writing to the original writer.
+// The decode overhead is only <30µs per write.
+// Reference: https://github.com/coreos/pkg/blob/master/capnslog/journald_formatter.go
+func NewJournaldWriter(wr io.Writer) io.Writer {
+	return &journaldWriter{Writer: wr}
+}
+
+type journaldWriter struct {
+	io.Writer
+}
+
+type logLine struct {
+	Level  string `json:"level"`
+	Caller string `json:"caller"`
+}
+
+func (w *journaldWriter) Write(p []byte) (int, error) {
+	line := &logLine{}
+	if err := json.NewDecoder(bytes.NewReader(p)).Decode(line); err != nil {
+		return 0, err
+	}
+
+	var pri journal.Priority
+	switch line.Level {
+	case zapcore.DebugLevel.String():
+		pri = journal.PriDebug
+	case zapcore.InfoLevel.String():
+		pri = journal.PriInfo
+
+	case zapcore.WarnLevel.String():
+		pri = journal.PriWarning
+	case zapcore.ErrorLevel.String():
+		pri = journal.PriErr
+
+	case zapcore.DPanicLevel.String():
+		pri = journal.PriCrit
+	case zapcore.PanicLevel.String():
+		pri = journal.PriCrit
+	case zapcore.FatalLevel.String():
+		pri = journal.PriCrit
+
+	default:
+		panic(fmt.Errorf("unknown log level: %q", line.Level))
+	}
+
+	err := journal.Send(string(p), pri, map[string]string{
+		"PACKAGE":           filepath.Dir(line.Caller),
+		"SYSLOG_IDENTIFIER": filepath.Base(os.Args[0]),
+	})
+	if err != nil {
+		fmt.Println("FAILED TO WRITE TO JOURNALD", err, string(p))
+		return w.Writer.Write(p)
+	}
+	return 0, nil
+}

pkg/logutil/zap_journald_test.go

@@ -0,0 +1,42 @@
+// Copyright 2018 The etcd Authors
+//
+// 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 logutil
+
+import (
+	"bytes"
+	"testing"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+func TestNewJournaldWriter(t *testing.T) {
+	buf := bytes.NewBuffer(nil)
+	syncer := zapcore.AddSync(NewJournaldWriter(buf))
+	cr := zapcore.NewCore(
+		zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig()),
+		syncer,
+		zap.NewAtomicLevelAt(zap.InfoLevel),
+	)
+
+	lg := zap.New(cr, zap.AddCaller(), zap.ErrorOutput(syncer))
+	defer lg.Sync()
+
+	lg.Info("TestNewJournaldWriter")
+	if buf.String() == "" {
+		// check with "journalctl -f"
+		t.Log("sent logs successfully to journald")
+	}
+}

pkg/logutil/zap_raft.go

@@ -0,0 +1,68 @@
+package logutil
+
+import (
+	"github.com/coreos/etcd/raft"
+	"go.uber.org/zap"
+)
+
+// NewRaftLogger converts "*zap.Logger" to "raft.Logger".
+func NewRaftLogger(lcfg zap.Config) (raft.Logger, error) {
+	lg, err := lcfg.Build(zap.AddCallerSkip(1)) // to annotate caller outside of "logutil"
+	if err != nil {
+		return nil, err
+	}
+	return &zapRaftLogger{lg: lg, sugar: lg.Sugar()}, nil
+}
+
+type zapRaftLogger struct {
+	lg    *zap.Logger
+	sugar *zap.SugaredLogger
+}
+
+func (zl *zapRaftLogger) Debug(args ...interface{}) {
+	zl.sugar.Debug(args...)
+}
+
+func (zl *zapRaftLogger) Debugf(format string, args ...interface{}) {
+	zl.sugar.Debugf(format, args...)
+}
+
+func (zl *zapRaftLogger) Error(args ...interface{}) {
+	zl.sugar.Error(args...)
+}
+
+func (zl *zapRaftLogger) Errorf(format string, args ...interface{}) {
+	zl.sugar.Errorf(format, args...)
+}
+
+func (zl *zapRaftLogger) Info(args ...interface{}) {
+	zl.sugar.Info(args...)
+}
+
+func (zl *zapRaftLogger) Infof(format string, args ...interface{}) {
+	zl.sugar.Infof(format, args...)
+}
+
+func (zl *zapRaftLogger) Warning(args ...interface{}) {
+	zl.sugar.Warn(args...)
+}
+
+func (zl *zapRaftLogger) Warningf(format string, args ...interface{}) {
+	zl.sugar.Warnf(format, args...)
+}
+
+func (zl *zapRaftLogger) Fatal(args ...interface{}) {
+	zl.sugar.Fatal(args...)
+}
+
+func (zl *zapRaftLogger) Fatalf(format string, args ...interface{}) {
+	zl.sugar.Fatalf(format, args...)
+}
+
+func (zl *zapRaftLogger) Panic(args ...interface{}) {
+	zl.sugar.Panic(args...)
+}
+
+func (zl *zapRaftLogger) Panicf(format string, args ...interface{}) {
+	zl.sugar.Panicf(format, args...)
+}

pkg/logutil/zap_raft_test.go

@@ -0,0 +1,70 @@
+// Copyright 2018 The etcd Authors
+//
+// 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 logutil
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+)
+
+func TestNewRaftLogger(t *testing.T) {
+	logPath := filepath.Join(os.TempDir(), fmt.Sprintf("test-log-%d", time.Now().UnixNano()))
+	defer os.RemoveAll(logPath)
+
+	lcfg := zap.Config{
+		Level:       zap.NewAtomicLevelAt(zap.DebugLevel),
+		Development: false,
+		Sampling: &zap.SamplingConfig{
+			Initial:    100,
+			Thereafter: 100,
+		},
+		Encoding:         "json",
+		EncoderConfig:    zap.NewProductionEncoderConfig(),
+		OutputPaths:      []string{logPath},
+		ErrorOutputPaths: []string{logPath},
+	}
+	gl, err := NewRaftLogger(lcfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	gl.Info("etcd-logutil-1")
+	data, err := ioutil.ReadFile(logPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Contains(data, []byte("etcd-logutil-1")) {
+		t.Fatalf("can't find data in log %q", string(data))
+	}
+
+	gl.Warning("etcd-logutil-2")
+	data, err = ioutil.ReadFile(logPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Contains(data, []byte("etcd-logutil-2")) {
+		t.Fatalf("can't find data in log %q", string(data))
+	}
+	if !bytes.Contains(data, []byte("logutil/zap_raft_test.go:")) {
+		t.Fatalf("unexpected caller; %q", string(data))
+	}
+}