embed: add "LogLevel", deprecate "Debug" in v3.5

Make log level configurable, and deprecate "debug" flag in v3.5.
And adds more warnings on flags that's being deprecated in v3.5.

Signed-off-by: Gyuho Lee <leegyuho@amazon.com>

embed/config.go

@@ -30,6 +30,7 @@ import (
 	"go.etcd.io/etcd/etcdserver"
 	"go.etcd.io/etcd/etcdserver/api/v3compactor"
 	"go.etcd.io/etcd/pkg/flags"
+	"go.etcd.io/etcd/pkg/logutil"
 	"go.etcd.io/etcd/pkg/netutil"
 	"go.etcd.io/etcd/pkg/srv"
 	"go.etcd.io/etcd/pkg/tlsutil"
@@ -291,11 +292,8 @@ type Config struct {
 	// Logger is logger options: "zap", "capnslog".
 	// WARN: "capnslog" is being deprecated in v3.5.
 	Logger string `json:"logger"`
-
-	// DeprecatedLogOutput is to be deprecated in v3.5.
-	// Just here for safe migration in v3.4.
-	DeprecatedLogOutput []string `json:"log-output"`
-
+	// LogLevel configures log level. Only supports debug, info, warn, error, panic, or fatal. Default 'info'.
+	LogLevel string `json:"log-level"`
 	// LogOutputs is either:
 	//  - "default" as os.Stderr,
 	//  - "stderr" as os.Stderr,
@@ -304,9 +302,6 @@ type Config struct {
 	// It can be multiple when "Logger" is zap.
 	LogOutputs []string `json:"log-outputs"`
 
-	// Debug is true, to enable debug level logging.
-	Debug bool `json:"debug"`
-
 	// zapLoggerBuilder is used to build the zap logger.
 	zapLoggerBuilder func(*Config) error
 
@@ -329,6 +324,12 @@ type Config struct {
 
 	// TO BE DEPRECATED
 
+	// DeprecatedLogOutput is to be deprecated in v3.5.
+	// Just here for safe migration in v3.4.
+	DeprecatedLogOutput []string `json:"log-output"`
+	// Debug is true, to enable debug level logging.
+	// WARNING: to be deprecated in 3.5. Use "--log-level=debug" instead.
+	Debug bool `json:"debug"`
 	// LogPkgLevels is being deprecated in v3.5.
 	// Only valid if "logger" option is "capnslog".
 	// WARN: DO NOT USE THIS!
@@ -415,6 +416,7 @@ func NewConfig() *Config {
 		DeprecatedLogOutput: []string{DefaultLogOutput},
 		LogOutputs:          []string{DefaultLogOutput},
 		Debug:               false,
+		LogLevel:            logutil.DefaultLogLevel,
 		LogPkgLevels:        "",
 	}
 	cfg.InitialCluster = cfg.InitialClusterFromName(cfg.Name)

embed/config_logging.go

@@ -69,11 +69,25 @@ func (cfg *Config) setupLogging() error {
 			return fmt.Errorf("'--log-output=%q' and '--log-outputs=%q' are incompatible; only set --log-outputs", cfg.DeprecatedLogOutput, cfg.LogOutputs)
 		}
 		if !reflect.DeepEqual(cfg.DeprecatedLogOutput, []string{DefaultLogOutput}) {
-			fmt.Fprintf(os.Stderr, "Deprecated '--log-output' flag is set to %q\n", cfg.DeprecatedLogOutput)
+			fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--log-output' flag is set to %q\n", cfg.DeprecatedLogOutput)
 			fmt.Fprintln(os.Stderr, "Please use '--log-outputs' flag")
 		}
 	}
 
+	// TODO: remove after deprecating log related flags in v3.5
+	if cfg.Debug {
+		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--debug' flag is set to %v (use '--log-level=debug' instead\n", cfg.Debug)
+	}
+	if cfg.Debug && cfg.LogLevel != "debug" {
+		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--debug' flag is set to %v with inconsistent '--log-level=%s' flag\n", cfg.Debug, cfg.LogLevel)
+	}
+	if cfg.Logger == "capnslog" {
+		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--logger=%s' flag is set; use '--logger=zap' flag instead\n", cfg.Logger)
+	}
+	if cfg.LogPkgLevels != "" {
+		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--log-package-levels=%s' flag is set; use '--logger=zap' flag instead\n", cfg.LogPkgLevels)
+	}
+
 	switch cfg.Logger {
 	case "capnslog": // TODO: deprecate this in v3.5
 		cfg.ClientTLSInfo.HandshakeFailure = logTLSHandshakeFailure
@@ -85,7 +99,7 @@ func (cfg *Config) setupLogging() error {
 			// enable info, warning, error
 			grpclog.SetLoggerV2(grpclog.NewLoggerV2(os.Stderr, os.Stderr, os.Stderr))
 		} else {
-			capnslog.SetGlobalLogLevel(capnslog.INFO)
+			capnslog.SetGlobalLogLevel(logutil.ConvertToCapnslogLogLevel(cfg.LogLevel))
 			// only discard info
 			grpclog.SetLoggerV2(grpclog.NewLoggerV2(ioutil.Discard, os.Stderr, os.Stderr))
 		}
@@ -157,9 +171,11 @@ func (cfg *Config) setupLogging() error {
 
 		if !isJournal {
 			copied := logutil.AddOutputPaths(logutil.DefaultZapLoggerConfig, outputPaths, errOutputPaths)
-
-			if cfg.Debug {
-				copied.Level = zap.NewAtomicLevelAt(zap.DebugLevel)
+			copied.Level = zap.NewAtomicLevelAt(logutil.ConvertToZapLevel(cfg.LogLevel))
+			if cfg.Debug || cfg.LogLevel == "debug" {
+				// enable tracing even when "--debug --log-level info"
+				// in order to keep backward compatibility with <= v3.3
+				// TODO: remove "Debug" check in v3.5
 				grpc.EnableTracing = true
 			}
 			if cfg.zapLoggerBuilder == nil {
@@ -201,9 +217,11 @@ func (cfg *Config) setupLogging() error {
 				return lerr
 			}
 
-			lvl := zap.NewAtomicLevelAt(zap.InfoLevel)
-			if cfg.Debug {
-				lvl = zap.NewAtomicLevelAt(zap.DebugLevel)
+			lvl := zap.NewAtomicLevelAt(logutil.ConvertToZapLevel(cfg.LogLevel))
+			if cfg.Debug || cfg.LogLevel == "debug" {
+				// enable tracing even when "--debug --log-level info"
+				// in order to keep backward compatibility with <= v3.3
+				// TODO: remove "Debug" check in v3.5
 				grpc.EnableTracing = true
 			}