feat: support zap logger's development mode

This PR adds a new flag `--enable-development-mode` to enable development mode
for the logger. If it is true, the logger panics at the DPanic level.

Author: ijsong

cmd/varlogadm/cli.go

@@ -79,6 +79,7 @@ func newStartCommand() *cli.Command {
 			flags.LogFileCompression,
 			flags.LogHumanReadable,
 			flags.LogLevel,
+			flags.EnableDevelopmentMode,
 
 			// telemetry
 			flags.TelemetryExporter,
@@ -101,7 +102,6 @@ func start(c *cli.Context) error {
 	if err != nil {
 		return err
 	}
-	logOpts = append(logOpts, log.WithZapLoggerOptions(zap.AddStacktrace(zap.DPanicLevel)))
 	logger, err := log.New(logOpts...)
 	if err != nil {
 		return err

cmd/varlogadm/testdata/varlogadm.ct

@@ -44,6 +44,7 @@ OPTIONS:
 
    Logger:
 
+   --enable-development-mode            Enable development mode for the logger. Panics on DPanic-level logs if true. (default: false) [$ENABLE_DEVELOPMENT_MODE]
    --log-human-readable                 Human-readable output. (default: false) [$LOG_HUMAN_READABLE]
    --logdir value, --log-dir value      Directory for the log files. [$LOGDIR, $LOG_DIR]
    --logfile-compression                Compress backup log files. (default: false) [$LOGFILE_COMPRESSION]

cmd/varlogmr/metadata_repository.go

@@ -9,7 +9,6 @@ import (
 
 	"github.com/urfave/cli/v2"
 	_ "go.uber.org/automaxprocs"
-	"go.uber.org/zap"
 
 	"github.com/kakao/varlog/internal/buildinfo"
 	"github.com/kakao/varlog/internal/flags"
@@ -31,7 +30,6 @@ func start(c *cli.Context) error {
 	if err != nil {
 		return err
 	}
-	logOpts = append(logOpts, log.WithZapLoggerOptions(zap.AddStacktrace(zap.DPanicLevel)))
 	logger, err := log.New(logOpts...)
 	if err != nil {
 		return err
@@ -168,6 +166,7 @@ func initCLI() *cli.App {
 				flags.LogFileCompression,
 				flags.LogHumanReadable,
 				flags.LogLevel,
+				flags.EnableDevelopmentMode,
 			},
 		}},
 	}

cmd/varlogsn/cli.go

@@ -95,6 +95,7 @@ func newStartCommand() *cli.Command {
 			flags.LogFileCompression,
 			flags.LogHumanReadable,
 			flags.LogLevel,
+			flags.EnableDevelopmentMode,
 
 			// telemetry
 			flags.TelemetryExporter,

cmd/varlogsn/testdata/varlogsn.ct

@@ -42,6 +42,7 @@ OPTIONS:
 
    Logger:
 
+   --enable-development-mode            Enable development mode for the logger. Panics on DPanic-level logs if true. (default: false) [$ENABLE_DEVELOPMENT_MODE]
    --log-human-readable                 Human-readable output. (default: false) [$LOG_HUMAN_READABLE]
    --logdir value, --log-dir value      Directory for the log files. [$LOGDIR, $LOG_DIR]
    --logfile-compression                Compress backup log files. (default: false) [$LOGFILE_COMPRESSION]

cmd/varlogsn/varlogsn.go

@@ -42,7 +42,6 @@ func start(c *cli.Context) error {
 	if err != nil {
 		return err
 	}
-	logOpts = append(logOpts, log.WithZapLoggerOptions(zap.AddStacktrace(zap.DPanicLevel)))
 	logger, err := log.New(logOpts...)
 	if err != nil {
 		return err

internal/flags/logger.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"github.com/urfave/cli/v2"
+	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 
 	"github.com/kakao/varlog/pkg/util/log"
@@ -113,6 +114,14 @@ var (
 		Value:    DefaultLogLevel,
 		Usage:    "Log levels, either debug, info, warn, or error case-insensitively.",
 	}
+
+	EnableDevelopmentMode = &cli.BoolFlag{
+		Name:     "enable-development-mode",
+		Category: CategoryLogger,
+		EnvVars:  []string{"ENABLE_DEVELOPMENT_MODE"},
+		Value:    false,
+		Usage:    "Enable development mode for the logger. Panics on DPanic-level logs if true.",
+	}
 )
 
 func ParseLoggerFlags(c *cli.Context, maybeLogFileName string) (opts []log.Option, err error) {
@@ -152,5 +161,11 @@ func ParseLoggerFlags(c *cli.Context, maybeLogFileName string) (opts []log.Optio
 	}
 	opts = append(opts, log.WithLogLevel(level))
 
+	var zapOpts []zap.Option
+	if c.Bool(EnableDevelopmentMode.Name) {
+		zapOpts = append(zapOpts, zap.Development())
+	}
+	opts = append(opts, log.WithZapLoggerOptions(zapOpts...))
+
 	return opts, nil
 }

pkg/util/log/log_test.go

@@ -3,6 +3,8 @@ package log
 import (
 	"testing"
 
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"go.uber.org/goleak"
 	"go.uber.org/zap"
 )
@@ -19,6 +21,39 @@ func ExampleLogger() {
 	logger.Info("this is log", zap.String("example", "first"))
 }
 
+func TestEnableDevelopmentMode(t *testing.T) {
+	tcs := []struct {
+		name       string
+		zapOpts    []zap.Option
+		assertFunc func(t require.TestingT, f assert.PanicTestFunc, msgAndArgs ...any)
+	}{
+		{
+			name:       "DevelopmentMode",
+			zapOpts:    []zap.Option{zap.Development()},
+			assertFunc: require.Panics,
+		},
+		{
+			name:       "ProductionMode",
+			zapOpts:    nil,
+			assertFunc: require.NotPanics,
+		},
+	}
+
+	for _, tc := range tcs {
+		t.Run(tc.name, func(t *testing.T) {
+			logger, err := New(WithZapLoggerOptions(tc.zapOpts...))
+			require.NoError(t, err)
+			defer func() {
+				_ = logger.Sync()
+			}()
+
+			tc.assertFunc(t, func() {
+				logger.DPanic("panic occur")
+			})
+		})
+	}
+}
+
 func TestMain(m *testing.M) {
 	goleak.VerifyTestMain(m)
 }