pkg/logutil: add "NewJournaldWriter"

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

pkg/logutil/zap_grpc_test.go

@@ -0,0 +1,72 @@
+// 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 TestNewGRPCLoggerV2(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.InfoLevel),
+		Development: false,
+		Sampling: &zap.SamplingConfig{
+			Initial:    100,
+			Thereafter: 100,
+		},
+		Encoding:         "json",
+		EncoderConfig:    zap.NewProductionEncoderConfig(),
+		OutputPaths:      []string{logPath},
+		ErrorOutputPaths: []string{logPath},
+	}
+	gl, err := NewGRPCLoggerV2(lcfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// debug level is not enabled,
+	// so info level gRPC-side logging is discarded
+	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("unexpected line %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_grpc_test.go:")) {
+		t.Fatalf("unexpected caller; %q", string(data))
+	}
+}