Ability to change log verbosity while the node is running

admin/admin.go

@@ -0,0 +1,43 @@
+// Copyright (c) 2024 The VeChainThor developers
+
+// Distributed under the GNU Lesser General Public License v3.0 software license, see the accompanying
+// file LICENSE or <https://www.gnu.org/licenses/lgpl-3.0.html>
+
+package admin
+
+import (
+	"fmt"
+	"log/slog"
+	"net/http"
+
+	"github.com/gorilla/handlers"
+	"github.com/gorilla/mux"
+	"github.com/vechain/thor/v2/log"
+)
+
+func HTTPHandler(logLevel *slog.LevelVar) http.Handler {
+	router := mux.NewRouter()
+	router.PathPrefix("/admin").Handler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		verbosity := r.URL.Query().Get("verbosity")
+		switch verbosity {
+		case "debug":
+			logLevel.Set(log.LevelDebug)
+		case "info":
+			logLevel.Set(log.LevelInfo)
+		case "warn":
+			logLevel.Set(log.LevelWarn)
+		case "error":
+			logLevel.Set(log.LevelError)
+		case "trace":
+			logLevel.Set(log.LevelTrace)
+		case "crit":
+			logLevel.Set(log.LevelCrit)
+		default:
+			http.Error(w, "Invalid verbosity level", http.StatusBadRequest)
+			return
+		}
+
+		fmt.Fprintln(w, "Verbosity changed to ", verbosity)
+	}))
+	return handlers.CompressHandler(router)
+}

cmd/disco/utils.go

@@ -9,6 +9,7 @@ import (
 	"crypto/ecdsa"
 	"fmt"
 	"io"
+	"log/slog"
 	"os"
 	"os/user"
 	"path/filepath"
@@ -19,15 +20,19 @@ import (
 	"github.com/vechain/thor/v2/log"
 )
 
-func initLogger(lvl int) {
+func initLogger(lvl int) *slog.LevelVar {
 	logLevel := log.FromLegacyLevel(lvl)
+	var level slog.LevelVar
+	level.Set(logLevel)
 	output := io.Writer(os.Stdout)
 	useColor := (isatty.IsTerminal(os.Stderr.Fd()) || isatty.IsCygwinTerminal(os.Stderr.Fd())) && os.Getenv("TERM") != "dumb"
-	handler := log.NewTerminalHandlerWithLevel(output, logLevel, useColor)
+	handler := log.NewTerminalHandlerWithLevel(output, &level, useColor)
 	log.SetDefault(log.NewLogger(handler))
 	ethlog.Root().SetHandler(&ethLogger{
 		logger: log.WithContext("pkg", "geth"),
 	})
+
+	return &level
 }
 
 type ethLogger struct {

cmd/thor/flags.go

@@ -150,6 +150,15 @@ var (
 		Value: "localhost:2112",
 		Usage: "metrics service listening address",
 	}
+	enableAdminFlag = cli.BoolFlag{
+		Name:  "enable-admin",
+		Usage: "enables admin service",
+	}
+	adminAddrFlag = cli.StringFlag{
+		Name:  "admin-addr",
+		Value: "localhost:2113",
+		Usage: "admin service listening address",
+	}
 
 	// solo mode only flags
 	onDemandFlag = cli.BoolFlag{

cmd/thor/main.go

@@ -93,6 +93,8 @@ func main() {
 			disablePrunerFlag,
 			enableMetricsFlag,
 			metricsAddrFlag,
+			adminAddrFlag,
+			enableAdminFlag,
 		},
 		Action: defaultAction,
 		Commands: []cli.Command{
@@ -125,6 +127,8 @@ func main() {
 					disablePrunerFlag,
 					enableMetricsFlag,
 					metricsAddrFlag,
+					adminAddrFlag,
+					enableAdminFlag,
 				},
 				Action: soloAction,
 			},
@@ -156,7 +160,7 @@ func defaultAction(ctx *cli.Context) error {
 	if err != nil {
 		return errors.Wrap(err, "parse verbosity flag")
 	}
-	initLogger(lvl, ctx.Bool(jsonLogsFlag.Name))
+	logLevel := initLogger(lvl, ctx.Bool(jsonLogsFlag.Name))
 
 	// enable metrics as soon as possible
 	metricsURL := ""
@@ -170,6 +174,16 @@ func defaultAction(ctx *cli.Context) error {
 		defer func() { log.Info("stopping metrics server..."); close() }()
 	}
 
+	adminURL := ""
+	if ctx.Bool(enableAdminFlag.Name) {
+		url, close, err := startAdminServer(ctx.String(adminAddrFlag.Name), logLevel)
+		if err != nil {
+			return fmt.Errorf("unable to start admin server - %w", err)
+		}
+		adminURL = url
+		defer func() { log.Info("stopping admin server..."); close() }()
+	}
+
 	gene, forkConfig, err := selectGenesis(ctx)
 	if err != nil {
 		return err
@@ -251,7 +265,7 @@ func defaultAction(ctx *cli.Context) error {
 	}
 	defer func() { log.Info("stopping API server..."); srvCloser() }()
 
-	printStartupMessage2(gene, apiURL, p2pCommunicator.Enode(), metricsURL)
+	printStartupMessage2(gene, apiURL, p2pCommunicator.Enode(), metricsURL, adminURL)
 
 	if err := p2pCommunicator.Start(); err != nil {
 		return err
@@ -283,7 +297,8 @@ func soloAction(ctx *cli.Context) error {
 	if err != nil {
 		return errors.Wrap(err, "parse verbosity flag")
 	}
-	initLogger(lvl, ctx.Bool(jsonLogsFlag.Name))
+
+	logLevel := initLogger(lvl, ctx.Bool(jsonLogsFlag.Name))
 
 	// enable metrics as soon as possible
 	metricsURL := ""
@@ -297,6 +312,16 @@ func soloAction(ctx *cli.Context) error {
 		defer func() { log.Info("stopping metrics server..."); close() }()
 	}
 
+	adminURL := ""
+	if ctx.Bool(enableAdminFlag.Name) {
+		url, close, err := startAdminServer(ctx.String(adminAddrFlag.Name), logLevel)
+		if err != nil {
+			return fmt.Errorf("unable to start admin server - %w", err)
+		}
+		adminURL = url
+		defer func() { log.Info("stopping admin server..."); close() }()
+	}
+
 	var (
 		gene       *genesis.Genesis
 		forkConfig thor.ForkConfig
@@ -397,7 +422,7 @@ func soloAction(ctx *cli.Context) error {
 		return errors.New("block-interval cannot be zero")
 	}
 
-	printSoloStartupMessage(gene, repo, instanceDir, apiURL, forkConfig, metricsURL)
+	printSoloStartupMessage(gene, repo, instanceDir, apiURL, forkConfig, metricsURL, adminURL)
 
 	optimizer := optimizer.New(mainDB, repo, !ctx.Bool(disablePrunerFlag.Name))
 	defer func() { log.Info("stopping optimizer..."); optimizer.Stop() }()

cmd/thor/utils.go

@@ -39,6 +39,7 @@ import (
 	"github.com/mattn/go-isatty"
 	"github.com/mattn/go-tty"
 	"github.com/pkg/errors"
+	"github.com/vechain/thor/v2/admin"
 	"github.com/vechain/thor/v2/api/doc"
 	"github.com/vechain/thor/v2/chain"
 	"github.com/vechain/thor/v2/cmd/thor/node"
@@ -60,21 +61,25 @@ import (
 
 var devNetGenesisID = genesis.NewDevnet().ID()
 
-func initLogger(lvl int, jsonLogs bool) {
+func initLogger(lvl int, jsonLogs bool) *slog.LevelVar {
 	logLevel := log.FromLegacyLevel(lvl)
 	output := io.Writer(os.Stdout)
+	var level slog.LevelVar
+	level.Set(logLevel)
 
 	var handler slog.Handler
 	if jsonLogs {
-		handler = log.JSONHandlerWithLevel(output, logLevel)
+		handler = log.JSONHandlerWithLevel(output, &level)
 	} else {
 		useColor := (isatty.IsTerminal(os.Stderr.Fd()) || isatty.IsCygwinTerminal(os.Stderr.Fd())) && os.Getenv("TERM") != "dumb"
-		handler = log.NewTerminalHandlerWithLevel(output, logLevel, useColor)
+		handler = log.NewTerminalHandlerWithLevel(output, &level, useColor)
 	}
 	log.SetDefault(log.NewLogger(handler))
 	ethlog.Root().SetHandler(ethlog.LvlFilterHandler(ethlog.LvlWarn, &ethLogger{
 		logger: log.WithContext("pkg", "geth"),
 	}))
+
+	return &level
 }
 
 type ethLogger struct {
@@ -587,6 +592,27 @@ func startMetricsServer(addr string) (string, func(), error) {
 	}, nil
 }
 
+func startAdminServer(addr string, logLevel *slog.LevelVar) (string, func(), error) {
+	listener, err := net.Listen("tcp", addr)
+	if err != nil {
+		return "", nil, errors.Wrapf(err, "listen admin API addr [%v]", addr)
+	}
+
+	router := mux.NewRouter()
+	router.PathPrefix("/admin").Handler(admin.HTTPHandler(logLevel))
+	handler := handlers.CompressHandler(router)
+
+	srv := &http.Server{Handler: handler, ReadHeaderTimeout: time.Second, ReadTimeout: 5 * time.Second}
+	var goes co.Goes
+	goes.Go(func() {
+		srv.Serve(listener)
+	})
+	return "http://" + listener.Addr().String() + "/admin", func() {
+		srv.Close()
+		goes.Wait()
+	}, nil
+}
+
 func printStartupMessage1(
 	gene *genesis.Genesis,
 	repo *chain.Repository,
@@ -638,8 +664,9 @@ func printStartupMessage2(
 	apiURL string,
 	nodeID string,
 	metricsURL string,
+	adminURL string,
 ) {
-	fmt.Printf(`%v    API portal   [ %v ]%v%v`,
+	fmt.Printf(`%v    API portal   [ %v ]%v%v%v`,
 		func() string { // node ID
 			if nodeID == "" {
 				return ""
@@ -659,6 +686,15 @@ func printStartupMessage2(
 					metricsURL)
 			}
 		}(),
+		func() string { // admin URL
+			if adminURL == "" {
+				return ""
+			} else {
+				return fmt.Sprintf(`
+    Admin        [ %v ]`,
+					adminURL)
+			}
+		}(),
 		func() string {
 			// print default dev net's dev accounts info
 			if gene.ID() == devNetGenesisID {
@@ -681,6 +717,7 @@ func printSoloStartupMessage(
 	apiURL string,
 	forkConfig thor.ForkConfig,
 	metricsURL string,
+	adminURL string,
 ) {
 	bestBlock := repo.BestBlockSummary()
 
@@ -691,6 +728,7 @@ func printSoloStartupMessage(
     Data dir    [ %v ]
     API portal  [ %v ]
     Metrics     [ %v ]
+    Admin       [ %v ]
 `,
 		common.MakeName("Thor solo", fullVersion()),
 		gene.ID(), gene.Name(),
@@ -704,6 +742,12 @@ func printSoloStartupMessage(
 			}
 			return metricsURL
 		}(),
+		func() string {
+			if adminURL == "" {
+				return "Disabled"
+			}
+			return adminURL
+		}(),
 	)
 
 	if gene.ID() == devNetGenesisID {

log/handler.go

@@ -55,7 +55,7 @@ func (h *discardHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
 type TerminalHandler struct {
 	mu       sync.Mutex
 	wr       io.Writer
-	lvl      slog.Level
+	lvl      *slog.LevelVar
 	useColor bool
 	attrs    []slog.Attr
 	// fieldPadding is a map with maximum field value lengths seen until now
@@ -75,12 +75,14 @@ type TerminalHandler struct {
 //
 //	[DBUG] [May 16 20:58:45] remove route ns=haproxy addr=127.0.0.1:50002
 func NewTerminalHandler(wr io.Writer, useColor bool) *TerminalHandler {
-	return NewTerminalHandlerWithLevel(wr, levelMaxVerbosity, useColor)
+	var level slog.LevelVar
+	level.Set(levelMaxVerbosity)
+	return NewTerminalHandlerWithLevel(wr, &level, useColor)
 }
 
 // NewTerminalHandlerWithLevel returns the same handler as NewTerminalHandler but only outputs
 // records which are less than or equal to the specified verbosity level.
-func NewTerminalHandlerWithLevel(wr io.Writer, lvl slog.Level, useColor bool) *TerminalHandler {
+func NewTerminalHandlerWithLevel(wr io.Writer, lvl *slog.LevelVar, useColor bool) *TerminalHandler {
 	return &TerminalHandler{
 		wr:           wr,
 		lvl:          lvl,
@@ -99,7 +101,7 @@ func (h *TerminalHandler) Handle(_ context.Context, r slog.Record) error {
 }
 
 func (h *TerminalHandler) Enabled(_ context.Context, level slog.Level) bool {
-	return level >= h.lvl
+	return level.Level() >= h.lvl.Level()
 }
 
 func (h *TerminalHandler) WithGroup(name string) slog.Handler {
@@ -123,20 +125,22 @@ func (t *TerminalHandler) ResetFieldPadding() {
 	t.mu.Unlock()
 }
 
-type leveler struct{ minLevel slog.Level }
+type leveler struct{ minLevel *slog.LevelVar }
 
 func (l *leveler) Level() slog.Level {
-	return l.minLevel
+	return l.minLevel.Level()
 }
 
 // JSONHandler returns a handler which prints records in JSON format.
 func JSONHandler(wr io.Writer) slog.Handler {
-	return JSONHandlerWithLevel(wr, levelMaxVerbosity)
+	var level slog.LevelVar
+	level.Set(levelMaxVerbosity)
+	return JSONHandlerWithLevel(wr, &level)
 }
 
 // JSONHandlerWithLevel returns a handler which prints records in JSON format that are less than or equal to
 // the specified verbosity level.
-func JSONHandlerWithLevel(wr io.Writer, level slog.Level) slog.Handler {
+func JSONHandlerWithLevel(wr io.Writer, level *slog.LevelVar) slog.Handler {
 	return slog.NewJSONHandler(wr, &slog.HandlerOptions{
 		ReplaceAttr: builtinReplaceJSON,
 		Level:       &leveler{level},
@@ -155,7 +159,7 @@ func LogfmtHandler(wr io.Writer) slog.Handler {
 
 // LogfmtHandlerWithLevel returns the same handler as LogfmtHandler but it only outputs
 // records which are less than or equal to the specified verbosity level.
-func LogfmtHandlerWithLevel(wr io.Writer, level slog.Level) slog.Handler {
+func LogfmtHandlerWithLevel(wr io.Writer, level *slog.LevelVar) slog.Handler {
 	return slog.NewTextHandler(wr, &slog.HandlerOptions{
 		ReplaceAttr: builtinReplaceLogfmt,
 		Level:       &leveler{level},