cmd/syncthing: Refactor command line parsing (#7330)

cmd/syncthing/blockprof.go

@@ -15,19 +15,17 @@ import (
 	"time"
 )
 
-func init() {
+func startBlockProfiler() {
-	if innerProcess && os.Getenv("STBLOCKPROFILE") != "" {
+	profiler := pprof.Lookup("block")
-		profiler := pprof.Lookup("block")
+	if profiler == nil {
-		if profiler == nil {
+		panic("Couldn't find block profiler")
-			panic("Couldn't find block profiler")
-		}
-		l.Debugln("Starting block profiling")
-		go func() {
-			err := saveBlockingProfiles(profiler) // Only returns on error
-			l.Warnln("Block profiler failed:", err)
-			panic("Block profiler failed")
-		}()
 	}
+	l.Debugln("Starting block profiling")
+	go func() {
+		err := saveBlockingProfiles(profiler) // Only returns on error
+		l.Warnln("Block profiler failed:", err)
+		panic("Block profiler failed")
+	}()
 }
 
 func saveBlockingProfiles(profiler *pprof.Profile) error {

cmd/syncthing/heapprof.go

@@ -11,24 +11,17 @@ import (
 	"os"
 	"runtime"
 	"runtime/pprof"
-	"strconv"
 	"syscall"
 	"time"
 )
 
-func init() {
+func startHeapProfiler() {
-	if innerProcess && os.Getenv("STHEAPPROFILE") != "" {
+	l.Debugln("Starting heap profiling")
-		rate := 1
+	go func() {
-		if i, err := strconv.Atoi(os.Getenv("STHEAPPROFILE")); err == nil {
+		err := saveHeapProfiles(1) // Only returns on error
-			rate = i
+		l.Warnln("Heap profiler failed:", err)
-		}
+		panic("Heap profiler failed")
-		l.Debugln("Starting heap profiling")
+	}()
-		go func() {
-			err := saveHeapProfiles(rate) // Only returns on error
-			l.Warnln("Heap profiler failed:", err)
-			panic("Heap profiler failed")
-		}()
-	}
 }
 
 func saveHeapProfiles(rate int) error {

cmd/syncthing/main.go

@@ -10,7 +10,6 @@ import (
 	"bytes"
 	"context"
 	"crypto/tls"
-	"flag"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -22,13 +21,16 @@ import (
 	"os/signal"
 	"path"
 	"path/filepath"
+	"regexp"
 	"runtime"
 	"runtime/pprof"
 	"sort"
 	"strconv"
+	"strings"
 	"syscall"
 	"time"
 
+	"github.com/alecthomas/kong"
 	"github.com/syncthing/syncthing/lib/build"
 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/db"
@@ -55,9 +57,8 @@ const (
 )
 
 const (
-	usage      = "syncthing [options]"
 	extraUsage = `
-The -logflags value is a sum of the following:
+The --logflags value is a sum of the following:
 
    1  Date
    2  Time
@@ -80,31 +81,11 @@ Development Settings
 --------------------
 
 The following environment variables modify Syncthing's behavior in ways that
-are mostly useful for developers. Use with care.
+are mostly useful for developers. Use with care. See also the --debug-* options
-
+above.
- STNODEFAULTFOLDER Don't create a default folder when starting for the first
-                   time. This variable will be ignored anytime after the first
-                   run.
-
- STGUIASSETS       Directory to load GUI assets from. Overrides compiled in
-                   assets.
 
  STTRACE           A comma separated string of facilities to trace. The valid
-                   facility strings listed below.
+                   facility strings are listed below.
-
- STPROFILER        Set to a listen address such as "127.0.0.1:9090" to start
-                   the profiler with HTTP access.
-
- STCPUPROFILE      Write a CPU profile to cpu-$pid.pprof on exit.
-
- STHEAPPROFILE     Write heap profiles to heap-$pid-$timestamp.pprof each time
-                   heap usage increases.
-
- STBLOCKPROFILE    Write block profiles to block-$pid-$timestamp.pprof every 20
-                   seconds.
-
- STPERFSTATS       Write running performance statistics to perf-$pid.csv. Not
-                   supported on Windows.
 
  STDEADLOCKTIMEOUT Used for debugging internal deadlocks; sets debug
                    sensitivity. Use only under direction of a developer.
@@ -112,24 +93,11 @@ are mostly useful for developers. Use with care.
  STLOCKTHRESHOLD   Used for debugging internal deadlocks; sets debug
                    sensitivity.  Use only under direction of a developer.
 
- STNORESTART       Equivalent to the -no-restart argument.
-
- STNOUPGRADE       Disable automatic upgrades.
-
  STHASHING         Select the SHA256 hashing package to use. Possible values
                    are "standard" for the Go standard library implementation,
                    "minio" for the github.com/minio/sha256-simd implementation,
                    and blank (the default) for auto detection.
 
- STRECHECKDBEVERY  Set to a time interval to override the default database
-                   check interval of 30 days (720h). The interval understands
-                   "h", "m" and "s" abbreviations for hours minutes and seconds.
-                   Valid values are like "720h", "30s", etc.
-
- STGCINDIRECTEVERY Set to a time interval to override the default database
-                   indirection GC interval of 13 hours. Same format as the
-                   STRECHECKDBEVERY variable.
-
  GOMAXPROCS        Set the maximum number of CPU cores to use. Defaults to all
                    available CPU cores.
 
@@ -143,75 +111,83 @@ Debugging Facilities
 
 The following are valid values for the STTRACE variable:
 
-%s`
+%s
+`
 )
 
 var (
-	// Environment options
-	innerProcess    = os.Getenv("STMONITORED") != ""
-	noDefaultFolder = os.Getenv("STNODEFAULTFOLDER") != ""
-
 	upgradeCheckInterval = 5 * time.Minute
 	upgradeRetryInterval = time.Hour
 	upgradeCheckKey      = "lastUpgradeCheck"
 	upgradeTimeKey       = "lastUpgradeTime"
 	upgradeVersionKey    = "lastUpgradeVersion"
 
-	errConcurrentUpgrade    = errors.New("upgrade prevented by other running Syncthing instance")
 	errTooEarlyUpgradeCheck = fmt.Errorf("last upgrade check happened less than %v ago, skipping", upgradeCheckInterval)
 	errTooEarlyUpgrade      = fmt.Errorf("last upgrade happened less than %v ago, skipping", upgradeRetryInterval)
 )
 
-type RuntimeOptions struct {
+// The cli struct is the main entry point for the command line parser. The
-	syncthing.Options
+// commands and options here are top level commands to syncthing.
-	homeDir          string
+var cli struct {
-	confDir          string
+	Serve serveOptions `cmd:"" help:"Run Syncthing"`
-	dataDir          string
-	resetDatabase    bool
-	showVersion      bool
-	showPaths        bool
-	showDeviceId     bool
-	doUpgrade        bool
-	doUpgradeCheck   bool
-	upgradeTo        string
-	noBrowser        bool
-	browserOnly      bool
-	hideConsole      bool
-	logFile          string
-	logMaxSize       int
-	logMaxFiles      int
-	auditEnabled     bool
-	auditFile        string
-	paused           bool
-	unpaused         bool
-	guiAddress       string
-	guiAPIKey        string
-	generateDir      string
-	noRestart        bool
-	cpuProfile       bool
-	stRestarting     bool
-	logFlags         int
-	showHelp         bool
-	allowNewerConfig bool
 }
 
-func defaultRuntimeOptions() RuntimeOptions {
+// serveOptions are the options for the `syncthing serve` command.
-	options := RuntimeOptions{
+type serveOptions struct {
-		Options: syncthing.Options{
+	AllowNewerConfig bool   `help:"Allow loading newer than current config version"`
-			AssetDir:    os.Getenv("STGUIASSETS"),
+	Audit            bool   `help:"Write events to audit file"`
-			NoUpgrade:   os.Getenv("STNOUPGRADE") != "",
+	AuditFile        string `name:"auditfile" placeholder:"PATH" help:"Specify audit file (use \"-\" for stdout, \"--\" for stderr)"`
-			ProfilerURL: os.Getenv("STPROFILER"),
+	BrowserOnly      bool   `help:"Open GUI in browser"`
-		},
+	ConfDir          string `name:"conf" placeholder:"PATH" help:"Set configuration directory (config and keys)"`
-		noRestart:    os.Getenv("STNORESTART") != "",
+	DataDir          string `name:"data" placeholder:"PATH" help:"Set data directory (database and logs)"`
-		cpuProfile:   os.Getenv("STCPUPROFILE") != "",
+	DeviceID         bool   `help:"Show the device ID"`
-		stRestarting: os.Getenv("STRESTART") != "",
+	GenerateDir      string `name:"generate" placeholder:"PATH" help:"Generate key and config in specified dir, then exit"`
-		logFlags:     log.Ltime,
+	GUIAddress       string `name:"gui-address" placeholder:"URL" help:"Override GUI address (e.g. \"http://192.0.2.42:8443\")"`
-		logMaxSize:   10 << 20, // 10 MiB
+	GUIAPIKey        string `name:"gui-apikey" placeholder:"API-KEY" help:"Override GUI API key"`
-		logMaxFiles:  3,        // plus the current one
+	HideConsole      bool   `help:"Hide console window (Windows only)"`
-	}
+	HomeDir          string `name:"home" placeholder:"PATH" help:"Set configuration and data directory"`
+	LogFile          string `placeholder:"PATH" help:"Log file name (see below)"`
+	LogFlags         int    `placeholder:"BITS" help:"Select information in log line prefix (see below)"`
+	LogMaxFiles      int    `placeholder:"N" name:"log-max-old-files" help:"Number of old files to keep (zero to keep only current)"`
+	LogMaxSize       int    `placeholder:"BYTES" help:"Maximum size of any file (zero to disable log rotation)"`
+	NoBrowser        bool   `help:"Do not start browser"`
+	NoRestart        bool   `env:"STNORESTART" help:"Do not restart Syncthing when exiting due to API/GUI command, upgrade, or crash"`
+	NoDefaultFolder  bool   `env:"STNODEFAULTFOLDER" help:"Don't create the \"default\" folder on first startup"`
+	NoUpgrade        bool   `env:"STNOUPGRADE" help:"Disable automatic upgrades"`
+	Paths            bool   `help:"Show configuration paths"`
+	Paused           bool   `help:"Start with all devices and folders paused"`
+	Unpaused         bool   `help:"Start with all devices and folders unpaused"`
+	Upgrade          bool   `help:"Perform upgrade"`
+	UpgradeCheck     bool   `help:"Check for available upgrade"`
+	UpgradeTo        string `placeholder:"URL" help:"Force upgrade directly from specified URL"`
+	Verbose          bool   `help:"Print verbose log output"`
+	Version          bool   `help:"Show version"`
+
+	// Debug options below
+	DebugDBIndirectGCInterval time.Duration `env:"STGCINDIRECTEVERY" help:"Database indirection GC interval"`
+	DebugDBRecheckInterval    time.Duration `env:"STRECHECKDBEVERY" help:"Database metadata recalculation interval"`
+	DebugDeadlockTimeout      int           `placeholder:"SECONDS" env:"STDEADLOCKTIMEOUT" help:"Used for debugging internal deadlocks"`
+	DebugGUIAssetsDir         string        `placeholder:"PATH" help:"Directory to load GUI assets from" env:"STGUIASSETS"`
+	DebugPerfStats            bool          `env:"STPERFSTATS" help:"Write running performance statistics to perf-$pid.csv (Unix only)"`
+	DebugProfileBlock         bool          `env:"STBLOCKPROFILE" help:"Write block profiles to block-$pid-$timestamp.pprof every 20 seconds"`
+	DebugProfileCPU           bool          `help:"Write a CPU profile to cpu-$pid.pprof on exit" env:"CPUPROFILE"`
+	DebugProfileHeap          bool          `env:"STHEAPPROFILE" help:"Write heap profiles to heap-$pid-$timestamp.pprof each time heap usage increases"`
+	DebugProfilerListen       string        `placeholder:"ADDR" env:"STPROFILER" help:"Network profiler listen address"`
+	DebugResetDatabase        bool          `name:"reset-database" help:"Reset the database, forcing a full rescan and resync"`
+	DebugResetDeltaIdxs       bool          `name:"reset-deltas" help:"Reset delta index IDs, forcing a full index exchange"`
+
+	// Internal options, not shown to users
+	InternalRestarting   bool `env:"STRESTART" hidden:"1"`
+	InternalInnerProcess bool `env:"STMONITORED" hidden:"1"`
+}
+
+func (options *serveOptions) setDefaults() {
+	options.LogFlags = log.Ltime
+	options.LogMaxSize = 10 << 20 // 10 MiB
+	options.LogMaxFiles = 3       // plus the current one
 
 	if os.Getenv("STTRACE") != "" {
-		options.logFlags = logger.DebugFlags
+		options.LogFlags = logger.DebugFlags
 	}
 
 	// On non-Windows, we explicitly default to "-" which means stdout. On
@@ -219,107 +195,97 @@ func defaultRuntimeOptions() RuntimeOptions {
 	// default path, unless the user has manually specified "-" or
 	// something else.
 	if runtime.GOOS == "windows" {
-		options.logFile = "default"
+		options.LogFile = "default"
 	} else {
-		options.logFile = "-"
+		options.LogFile = "-"
 	}
-
-	return options
-}
-
-func parseCommandLineOptions() RuntimeOptions {
-	options := defaultRuntimeOptions()
-
-	flag.StringVar(&options.generateDir, "generate", "", "Generate key and config in specified dir, then exit")
-	flag.StringVar(&options.guiAddress, "gui-address", options.guiAddress, "Override GUI address (e.g. \"http://192.0.2.42:8443\")")
-	flag.StringVar(&options.guiAPIKey, "gui-apikey", options.guiAPIKey, "Override GUI API key")
-	flag.StringVar(&options.homeDir, "home", "", "Set configuration and data directory")
-	flag.StringVar(&options.confDir, "config", "", "Set configuration directory (config and keys)")
-	flag.StringVar(&options.dataDir, "data", "", "Set data directory (database and logs)")
-	flag.IntVar(&options.logFlags, "logflags", options.logFlags, "Select information in log line prefix (see below)")
-	flag.BoolVar(&options.noBrowser, "no-browser", false, "Do not start browser")
-	flag.BoolVar(&options.browserOnly, "browser-only", false, "Open GUI in browser")
-	flag.BoolVar(&options.noRestart, "no-restart", options.noRestart, "Do not restart Syncthing when exiting due to API/GUI command, upgrade, or crash")
-	flag.BoolVar(&options.resetDatabase, "reset-database", false, "Reset the database, forcing a full rescan and resync")
-	flag.BoolVar(&options.ResetDeltaIdxs, "reset-deltas", false, "Reset delta index IDs, forcing a full index exchange")
-	flag.BoolVar(&options.doUpgrade, "upgrade", false, "Perform upgrade")
-	flag.BoolVar(&options.doUpgradeCheck, "upgrade-check", false, "Check for available upgrade")
-	flag.BoolVar(&options.showVersion, "version", false, "Show version")
-	flag.BoolVar(&options.showHelp, "help", false, "Show this help")
-	flag.BoolVar(&options.showPaths, "paths", false, "Show configuration paths")
-	flag.BoolVar(&options.showDeviceId, "device-id", false, "Show the device ID")
-	flag.StringVar(&options.upgradeTo, "upgrade-to", options.upgradeTo, "Force upgrade directly from specified URL")
-	flag.BoolVar(&options.auditEnabled, "audit", false, "Write events to audit file")
-	flag.BoolVar(&options.Verbose, "verbose", false, "Print verbose log output")
-	flag.BoolVar(&options.paused, "paused", false, "Start with all devices and folders paused")
-	flag.BoolVar(&options.unpaused, "unpaused", false, "Start with all devices and folders unpaused")
-	flag.StringVar(&options.logFile, "logfile", options.logFile, "Log file name (see below).")
-	flag.IntVar(&options.logMaxSize, "log-max-size", options.logMaxSize, "Maximum size of any file (zero to disable log rotation).")
-	flag.IntVar(&options.logMaxFiles, "log-max-old-files", options.logMaxFiles, "Number of old files to keep (zero to keep only current).")
-	flag.StringVar(&options.auditFile, "auditfile", options.auditFile, "Specify audit file (use \"-\" for stdout, \"--\" for stderr)")
-	flag.BoolVar(&options.allowNewerConfig, "allow-newer-config", false, "Allow loading newer than current config version")
-	if runtime.GOOS == "windows" {
-		// Allow user to hide the console window
-		flag.BoolVar(&options.hideConsole, "no-console", false, "Hide console window")
-	}
-
-	longUsage := fmt.Sprintf(extraUsage, debugFacilities())
-	flag.Usage = usageFor(flag.CommandLine, usage, longUsage)
-	flag.Parse()
-
-	if len(flag.Args()) > 0 {
-		flag.Usage()
-		os.Exit(2)
-	}
-
-	return options
-}
-
-func setLocation(enum locations.BaseDirEnum, loc string) error {
-	if !filepath.IsAbs(loc) {
-		var err error
-		loc, err = filepath.Abs(loc)
-		if err != nil {
-			return err
-		}
-	}
-	return locations.SetBaseDir(enum, loc)
 }
 
 func main() {
-	options := parseCommandLineOptions()
+	// First some massaging of the raw command line to fit the new model.
-	l.SetFlags(options.logFlags)
+	// Basically this means adding the default command at the front, and
+	// converting -options to --options.
 
-	if options.guiAddress != "" {
+	args := os.Args[1:]
-		// The config picks this up from the environment.
+	switch {
-		os.Setenv("STGUIADDRESS", options.guiAddress)
+	case len(args) == 0:
-	}
+		// Empty command line is equivalent to just calling serve
-	if options.guiAPIKey != "" {
+		args = []string{"serve"}
-		// The config picks this up from the environment.
+	case args[0] == "-help":
-		os.Setenv("STGUIAPIKEY", options.guiAPIKey)
+		// For consistency, we consider this equivalent with --help even
+		// though kong would otherwise consider it a bad flag.
+		args[0] = "--help"
+	case args[0] == "-h", args[0] == "--help":
+		// Top level request for help, let it pass as-is to be handled by
+		// kong to list commands.
+	case strings.HasPrefix(args[0], "-"):
+		// There are flags not preceded by a command, so we tack on the
+		// "serve" command and convert the old style arguments (single dash)
+		// to new style (double dash).
+		args = append([]string{"serve"}, convertLegacyArgs(args)...)
 	}
 
-	if options.hideConsole {
+	cli.Serve.setDefaults()
+
+	// Create a parser with an overridden help function to print our extra
+	// help info.
+	parser, err := kong.New(&cli, kong.Help(extraHelpPrinter))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	ctx, err := parser.Parse(args)
+	parser.FatalIfErrorf(err)
+	err = ctx.Run()
+	parser.FatalIfErrorf(err)
+}
+
+func extraHelpPrinter(options kong.HelpOptions, ctx *kong.Context) error {
+	if err := kong.DefaultHelpPrinter(options, ctx); err != nil {
+		return err
+	}
+	if ctx.Command() == "serve" {
+		// Help was requested for `syncthing serve`, so we add our extra
+		// usage info afte the normal options output.
+		fmt.Printf(extraUsage, debugFacilities())
+	}
+	return nil
+}
+
+// serveOptions.Run() is the entrypoint for `syncthing serve`
+func (options serveOptions) Run() error {
+	l.SetFlags(options.LogFlags)
+
+	if options.GUIAddress != "" {
+		// The config picks this up from the environment.
+		os.Setenv("STGUIADDRESS", options.GUIAddress)
+	}
+	if options.GUIAPIKey != "" {
+		// The config picks this up from the environment.
+		os.Setenv("STGUIAPIKEY", options.GUIAPIKey)
+	}
+
+	if options.HideConsole {
 		osutil.HideConsole()
 	}
 
 	// Not set as default above because the strings can be really long.
 	var err error
-	homeSet := options.homeDir != ""
+	homeSet := options.HomeDir != ""
-	confSet := options.confDir != ""
+	confSet := options.ConfDir != ""
-	dataSet := options.dataDir != ""
+	dataSet := options.DataDir != ""
 	switch {
 	case dataSet != confSet:
 		err = errors.New("either both or none of -conf and -data must be given, use -home to set both at once")
 	case homeSet && dataSet:
 		err = errors.New("-home must not be used together with -conf and -data")
 	case homeSet:
-		if err = setLocation(locations.ConfigBaseDir, options.homeDir); err == nil {
+		if err = setLocation(locations.ConfigBaseDir, options.HomeDir); err == nil {
-			err = setLocation(locations.DataBaseDir, options.homeDir)
+			err = setLocation(locations.DataBaseDir, options.HomeDir)
 		}
 	case dataSet:
-		if err = setLocation(locations.ConfigBaseDir, options.confDir); err == nil {
+		if err = setLocation(locations.ConfigBaseDir, options.ConfDir); err == nil {
-			err = setLocation(locations.DataBaseDir, options.dataDir)
+			err = setLocation(locations.DataBaseDir, options.DataDir)
 		}
 	}
 	if err != nil {
@@ -327,34 +293,29 @@ func main() {
 		os.Exit(svcutil.ExitError.AsInt())
 	}
 
-	if options.logFile == "default" || options.logFile == "" {
+	if options.LogFile == "default" || options.LogFile == "" {
 		// We must set this *after* expandLocations above.
 		// Handling an empty value is for backwards compatibility (<1.4.1).
-		options.logFile = locations.Get(locations.LogFile)
+		options.LogFile = locations.Get(locations.LogFile)
 	}
 
-	if options.AssetDir == "" {
+	if options.DebugGUIAssetsDir == "" {
 		// The asset dir is blank if STGUIASSETS wasn't set, in which case we
 		// should look for extra assets in the default place.
-		options.AssetDir = locations.Get(locations.GUIAssets)
+		options.DebugGUIAssetsDir = locations.Get(locations.GUIAssets)
 	}
 
-	if options.showVersion {
+	if options.Version {
 		fmt.Println(build.LongVersion)
-		return
+		return nil
 	}
 
-	if options.showHelp {
+	if options.Paths {
-		flag.Usage()
-		return
-	}
-
-	if options.showPaths {
 		showPaths(options)
-		return
+		return nil
 	}
 
-	if options.showDeviceId {
+	if options.DeviceID {
 		cert, err := tls.LoadX509KeyPair(
 			locations.Get(locations.CertFile),
 			locations.Get(locations.KeyFile),
@@ -365,23 +326,23 @@ func main() {
 		}
 
 		fmt.Println(protocol.NewDeviceID(cert.Certificate[0]))
-		return
+		return nil
 	}
 
-	if options.browserOnly {
+	if options.BrowserOnly {
 		if err := openGUI(protocol.EmptyDeviceID); err != nil {
 			l.Warnln("Failed to open web UI:", err)
 			os.Exit(svcutil.ExitError.AsInt())
 		}
-		return
+		return nil
 	}
 
-	if options.generateDir != "" {
+	if options.GenerateDir != "" {
-		if err := generate(options.generateDir); err != nil {
+		if err := generate(options.GenerateDir, options.NoDefaultFolder); err != nil {
 			l.Warnln("Failed to generate config and keys:", err)
 			os.Exit(svcutil.ExitError.AsInt())
 		}
-		return
+		return nil
 	}
 
 	// Ensure that our home directory exists.
@@ -390,25 +351,25 @@ func main() {
 		os.Exit(svcutil.ExitError.AsInt())
 	}
 
-	if options.upgradeTo != "" {
+	if options.UpgradeTo != "" {
-		err := upgrade.ToURL(options.upgradeTo)
+		err := upgrade.ToURL(options.UpgradeTo)
 		if err != nil {
 			l.Warnln("Error while Upgrading:", err)
 			os.Exit(svcutil.ExitError.AsInt())
 		}
-		l.Infoln("Upgraded from", options.upgradeTo)
+		l.Infoln("Upgraded from", options.UpgradeTo)
-		return
+		return nil
 	}
 
-	if options.doUpgradeCheck {
+	if options.UpgradeCheck {
 		if _, err := checkUpgrade(); err != nil {
 			l.Warnln("Checking for upgrade:", err)
 			os.Exit(exitCodeForUpgrade(err))
 		}
-		return
+		return nil
 	}
 
-	if options.doUpgrade {
+	if options.Upgrade {
 		release, err := checkUpgrade()
 		if err == nil {
 			// Use leveldb database locks to protect against concurrent upgrades
@@ -428,24 +389,25 @@ func main() {
 		os.Exit(svcutil.ExitUpgrade.AsInt())
 	}
 
-	if options.resetDatabase {
+	if options.DebugResetDatabase {
 		if err := resetDB(); err != nil {
 			l.Warnln("Resetting database:", err)
 			os.Exit(svcutil.ExitError.AsInt())
 		}
 		l.Infoln("Successfully reset database - it will be rebuilt after next start.")
-		return
+		return nil
 	}
 
-	if innerProcess {
+	if options.InternalInnerProcess {
 		syncthingMain(options)
 	} else {
 		monitorMain(options)
 	}
+	return nil
 }
 
 func openGUI(myID protocol.DeviceID) error {
-	cfg, err := loadOrDefaultConfig(myID, events.NoopLogger)
+	cfg, err := loadOrDefaultConfig(myID, events.NoopLogger, true)
 	if err != nil {
 		return err
 	}
@@ -459,7 +421,7 @@ func openGUI(myID protocol.DeviceID) error {
 	return nil
 }
 
-func generate(generateDir string) error {
+func generate(generateDir string, noDefaultFolder bool) error {
 	dir, err := fs.ExpandTilde(generateDir)
 	if err != nil {
 		return err
@@ -530,7 +492,7 @@ func (e *errNoUpgrade) Error() string {
 }
 
 func checkUpgrade() (upgrade.Release, error) {
-	cfg, err := loadOrDefaultConfig(protocol.EmptyDeviceID, events.NoopLogger)
+	cfg, err := loadOrDefaultConfig(protocol.EmptyDeviceID, events.NoopLogger, true)
 	if err != nil {
 		return upgrade.Release{}, err
 	}
@@ -549,7 +511,7 @@ func checkUpgrade() (upgrade.Release, error) {
 }
 
 func upgradeViaRest() error {
-	cfg, _ := loadOrDefaultConfig(protocol.EmptyDeviceID, events.NoopLogger)
+	cfg, _ := loadOrDefaultConfig(protocol.EmptyDeviceID, events.NoopLogger, true)
 	u, err := url.Parse(cfg.GUI().URL())
 	if err != nil {
 		return err
@@ -584,7 +546,17 @@ func upgradeViaRest() error {
 	return err
 }
 
-func syncthingMain(runtimeOptions RuntimeOptions) {
+func syncthingMain(options serveOptions) {
+	if options.DebugProfileBlock {
+		startBlockProfiler()
+	}
+	if options.DebugProfileHeap {
+		startHeapProfiler()
+	}
+	if options.DebugPerfStats {
+		startPerfStats()
+	}
+
 	// Set a log prefix similar to the ID we will have later on, or early log
 	// lines look ugly.
 	l.SetPrefix("[start] ")
@@ -615,7 +587,7 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 	evLogger := events.NewLogger()
 	earlyService.Add(evLogger)
 
-	cfgWrapper, err := syncthing.LoadConfigAtStartup(locations.Get(locations.ConfigFile), cert, evLogger, runtimeOptions.allowNewerConfig, noDefaultFolder)
+	cfgWrapper, err := syncthing.LoadConfigAtStartup(locations.Get(locations.ConfigFile), cert, evLogger, options.AllowNewerConfig, options.NoDefaultFolder)
 	if err != nil {
 		l.Warnln("Failed to initialize config:", err)
 		os.Exit(svcutil.ExitError.AsInt())
@@ -628,7 +600,7 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 	// unless we are in a build where it's disabled or the STNOUPGRADE
 	// environment variable is set.
 
-	if build.IsCandidate && !upgrade.DisabledByCompilation && !runtimeOptions.NoUpgrade {
+	if build.IsCandidate && !upgrade.DisabledByCompilation && !options.NoUpgrade {
 		cfgWrapper.Modify(func(cfg *config.Configuration) {
 			l.Infoln("Automatic upgrade is always enabled for candidate releases.")
 			if cfg.Options.AutoUpgradeIntervalH == 0 || cfg.Options.AutoUpgradeIntervalH > 24 {
@@ -652,7 +624,7 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 	// upgrade immedately. The auto-upgrade routine can only be started
 	// later after App is initialised.
 
-	autoUpgradePossible := autoUpgradePossible(runtimeOptions)
+	autoUpgradePossible := autoUpgradePossible(options)
 	if autoUpgradePossible && cfgWrapper.Options().AutoUpgradeEnabled() {
 		// try to do upgrade directly and log the error if relevant.
 		release, err := initialAutoUpgradeCheck(db.NewMiscDataNamespace(ldb))
@@ -671,15 +643,24 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 		}
 	}
 
-	if runtimeOptions.unpaused {
+	if options.Unpaused {
 		setPauseState(cfgWrapper, false)
-	} else if runtimeOptions.paused {
+	} else if options.Paused {
 		setPauseState(cfgWrapper, true)
 	}
 
-	appOpts := runtimeOptions.Options
+	appOpts := syncthing.Options{
-	if runtimeOptions.auditEnabled {
+		AssetDir:             options.DebugGUIAssetsDir,
-		appOpts.AuditWriter = auditWriter(runtimeOptions.auditFile)
+		DeadlockTimeoutS:     options.DebugDeadlockTimeout,
+		NoUpgrade:            options.NoUpgrade,
+		ProfilerAddr:         options.DebugProfilerListen,
+		ResetDeltaIdxs:       options.DebugResetDeltaIdxs,
+		Verbose:              options.Verbose,
+		DBRecheckInterval:    options.DebugDBRecheckInterval,
+		DBIndirectGCInterval: options.DebugDBIndirectGCInterval,
+	}
+	if options.Audit {
+		appOpts.AuditWriter = auditWriter(options.AuditFile)
 	}
 	if t := os.Getenv("STDEADLOCKTIMEOUT"); t != "" {
 		secs, _ := strconv.Atoi(t)
@@ -708,7 +689,7 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 		runtime.GOMAXPROCS(runtime.NumCPU())
 	}
 
-	if runtimeOptions.cpuProfile {
+	if options.DebugProfileCPU {
 		f, err := os.Create(fmt.Sprintf("cpu-%d.pprof", os.Getpid()))
 		if err != nil {
 			l.Warnln("Creating profile:", err)
@@ -728,7 +709,7 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 
 	cleanConfigDirectory()
 
-	if cfgWrapper.Options().StartBrowser && !runtimeOptions.noBrowser && !runtimeOptions.stRestarting {
+	if cfgWrapper.Options().StartBrowser && !options.NoBrowser && !options.InternalRestarting {
 		// Can potentially block if the utility we are invoking doesn't
 		// fork, and just execs, hence keep it in its own routine.
 		go func() { _ = openURL(cfgWrapper.GUI().URL()) }()
@@ -740,7 +721,7 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 		l.Warnln("Syncthing stopped with error:", app.Error())
 	}
 
-	if runtimeOptions.cpuProfile {
+	if options.DebugProfileCPU {
 		pprof.StopCPUProfile()
 	}
 
@@ -768,7 +749,7 @@ func setupSignalHandling(app *syncthing.App) {
 	}()
 }
 
-func loadOrDefaultConfig(myID protocol.DeviceID, evLogger events.Logger) (config.Wrapper, error) {
+func loadOrDefaultConfig(myID protocol.DeviceID, evLogger events.Logger, noDefaultFolder bool) (config.Wrapper, error) {
 	cfgFile := locations.Get(locations.ConfigFile)
 	cfg, _, err := config.Load(cfgFile, myID, evLogger)
 
@@ -858,11 +839,11 @@ func standbyMonitor(app *syncthing.App, cfg config.Wrapper) {
 	}
 }
 
-func autoUpgradePossible(runtimeOptions RuntimeOptions) bool {
+func autoUpgradePossible(options serveOptions) bool {
 	if upgrade.DisabledByCompilation {
 		return false
 	}
-	if runtimeOptions.NoUpgrade {
+	if options.NoUpgrade {
 		l.Infof("No automatic upgrades; STNOUPGRADE environment variable defined.")
 		return false
 	}
@@ -989,13 +970,13 @@ func cleanConfigDirectory() {
 	}
 }
 
-func showPaths(options RuntimeOptions) {
+func showPaths(options serveOptions) {
 	fmt.Printf("Configuration file:\n\t%s\n\n", locations.Get(locations.ConfigFile))
 	fmt.Printf("Database directory:\n\t%s\n\n", locations.Get(locations.Database))
 	fmt.Printf("Device private key & certificate files:\n\t%s\n\t%s\n\n", locations.Get(locations.KeyFile), locations.Get(locations.CertFile))
 	fmt.Printf("HTTPS private key & certificate files:\n\t%s\n\t%s\n\n", locations.Get(locations.HTTPSKeyFile), locations.Get(locations.HTTPSCertFile))
-	fmt.Printf("Log file:\n\t%s\n\n", options.logFile)
+	fmt.Printf("Log file:\n\t%s\n\n", options.LogFile)
-	fmt.Printf("GUI override directory:\n\t%s\n\n", options.AssetDir)
+	fmt.Printf("GUI override directory:\n\t%s\n\n", options.DebugGUIAssetsDir)
 	fmt.Printf("Default sync folder directory:\n\t%s\n\n", locations.Get(locations.DefFolder))
 }
 
@@ -1020,3 +1001,32 @@ func exitCodeForUpgrade(err error) int {
 	}
 	return svcutil.ExitError.AsInt()
 }
+
+func setLocation(enum locations.BaseDirEnum, loc string) error {
+	if !filepath.IsAbs(loc) {
+		var err error
+		loc, err = filepath.Abs(loc)
+		if err != nil {
+			return err
+		}
+	}
+	return locations.SetBaseDir(enum, loc)
+}
+
+// convertLegacyArgs returns the slice of arguments with single dash long
+// flags converted to double dash long flags.
+func convertLegacyArgs(args []string) []string {
+	// Legacy args begin with a single dash, followed by two or more characters.
+	legacyExp := regexp.MustCompile(`^-\w{2,}`)
+
+	res := make([]string, len(args))
+	for i, arg := range args {
+		if legacyExp.MatchString(arg) {
+			res[i] = "-" + arg
+		} else {
+			res[i] = arg
+		}
+	}
+
+	return res
+}

cmd/syncthing/monitor.go

@@ -44,12 +44,12 @@ const (
 	panicUploadNoticeWait = 10 * time.Second
 )
 
-func monitorMain(runtimeOptions RuntimeOptions) {
+func monitorMain(options serveOptions) {
 	l.SetPrefix("[monitor] ")
 
 	var dst io.Writer = os.Stdout
 
-	logFile := runtimeOptions.logFile
+	logFile := options.LogFile
 	if logFile != "-" {
 		if expanded, err := fs.ExpandTilde(logFile); err == nil {
 			logFile = expanded
@@ -59,8 +59,8 @@ func monitorMain(runtimeOptions RuntimeOptions) {
 		open := func(name string) (io.WriteCloser, error) {
 			return newAutoclosedFile(name, logFileAutoCloseDelay, logFileMaxOpenTime)
 		}
-		if runtimeOptions.logMaxSize > 0 {
+		if options.LogMaxSize > 0 {
-			fileDst, err = newRotatedFile(logFile, open, int64(runtimeOptions.logMaxSize), runtimeOptions.logMaxFiles)
+			fileDst, err = newRotatedFile(logFile, open, int64(options.LogMaxSize), options.LogMaxFiles)
 		} else {
 			fileDst, err = open(logFile)
 		}
@@ -174,7 +174,7 @@ func monitorMain(runtimeOptions RuntimeOptions) {
 
 		if exiterr, ok := err.(*exec.ExitError); ok {
 			exitCode := exiterr.ExitCode()
-			if stopped || runtimeOptions.noRestart {
+			if stopped || options.NoRestart {
 				os.Exit(exitCode)
 			}
 			if exitCode == svcutil.ExitUpgrade.AsInt() {
@@ -188,7 +188,7 @@ func monitorMain(runtimeOptions RuntimeOptions) {
 			}
 		}
 
-		if runtimeOptions.noRestart {
+		if options.NoRestart {
 			os.Exit(svcutil.ExitError.AsInt())
 		}
 
@@ -563,7 +563,7 @@ func childEnv() []string {
 // panicUploadMaxWait uploading panics...
 func maybeReportPanics() {
 	// Try to get a config to see if/where panics should be reported.
-	cfg, err := loadOrDefaultConfig(protocol.EmptyDeviceID, events.NoopLogger)
+	cfg, err := loadOrDefaultConfig(protocol.EmptyDeviceID, events.NoopLogger, true)
 	if err != nil {
 		l.Warnln("Couldn't load config; not reporting crash")
 		return

cmd/syncthing/perfstats_unix.go

@@ -18,10 +18,8 @@ import (
 	"github.com/syncthing/syncthing/lib/protocol"
 )
 
-func init() {
+func startPerfStats() {
-	if innerProcess && os.Getenv("STPERFSTATS") != "" {
+	go savePerfStats(fmt.Sprintf("perfstats-%d.csv", syscall.Getpid()))
-		go savePerfStats(fmt.Sprintf("perfstats-%d.csv", syscall.Getpid()))
-	}
 }
 
 func savePerfStats(file string) {

cmd/syncthing/perfstats_unsupported.go

@@ -0,0 +1,12 @@
+// Copyright (C) 2021 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+// +build solaris windows
+
+package main
+
+func startPerfStats() {
+}

cmd/syncthing/usage.go

@@ -1,57 +0,0 @@
-// Copyright (C) 2014 The Syncthing Authors.
-//
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at https://mozilla.org/MPL/2.0/.
-
-package main
-
-import (
-	"bytes"
-	"flag"
-	"fmt"
-	"io"
-	"text/tabwriter"
-)
-
-func optionTable(w io.Writer, rows [][]string) {
-	tw := tabwriter.NewWriter(w, 2, 4, 2, ' ', 0)
-	for _, row := range rows {
-		for i, cell := range row {
-			if i > 0 {
-				tw.Write([]byte("\t"))
-			}
-			tw.Write([]byte(cell))
-		}
-		tw.Write([]byte("\n"))
-	}
-	tw.Flush()
-}
-
-func usageFor(fs *flag.FlagSet, usage string, extra string) func() {
-	return func() {
-		var b bytes.Buffer
-		b.WriteString("Usage:\n  " + usage + "\n")
-
-		var options [][]string
-		fs.VisitAll(func(f *flag.Flag) {
-			var opt = "  -" + f.Name
-
-			if f.DefValue != "false" {
-				opt += "=" + fmt.Sprintf(`"%s"`, f.DefValue)
-			}
-			options = append(options, []string{opt, f.Usage})
-		})
-
-		if len(options) > 0 {
-			b.WriteString("\nOptions:\n")
-			optionTable(&b, options)
-		}
-
-		fmt.Println(b.String())
-
-		if len(extra) > 0 {
-			fmt.Println(extra)
-		}
-	}
-}

go.mod

@@ -3,6 +3,7 @@ module github.com/syncthing/syncthing
 require (
 	github.com/AudriusButkevicius/pfilter v0.0.0-20190627213056-c55ef6137fc6
 	github.com/AudriusButkevicius/recli v0.0.5
+	github.com/alecthomas/kong v0.2.12
 	github.com/bkaradzic/go-lz4 v0.0.0-20160924222819-7224d8d8f27e
 	github.com/calmh/xdr v1.1.0
 	github.com/ccding/go-stun v0.1.2

go.sum

@@ -25,6 +25,8 @@ github.com/StackExchange/wmi v0.0.0-20190523213315-cbe66965904d h1:G0m3OIz70MZUW
 github.com/StackExchange/wmi v0.0.0-20190523213315-cbe66965904d/go.mod h1:3eOhrUMpNV+6aFIbp5/iudMxNCF27Vw2OZgy4xEx0Fg=
 github.com/VividCortex/gohistogram v1.0.0/go.mod h1:Pf5mBqqDxYaXu3hDrrU+w6nw50o/4+TcAqDqk/vUH7g=
 github.com/afex/hystrix-go v0.0.0-20180502004556-fa1af6a1f4f5/go.mod h1:SkGFH1ia65gfNATL8TAiHDNxPzPdmEL5uirI2Uyuz6c=
+github.com/alecthomas/kong v0.2.12 h1:X3kkCOXGUNzLmiu+nQtoxWqj4U2a39MpSJR3QdQXOwI=
+github.com/alecthomas/kong v0.2.12/go.mod h1:kQOmtJgV+Lb4aj+I2LEn40cbtawdWJ9Y8QLq+lElKxE=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=

lib/syncthing/syncthing.go

@@ -57,7 +57,7 @@ type Options struct {
 	AuditWriter      io.Writer
 	DeadlockTimeoutS int
 	NoUpgrade        bool
-	ProfilerURL      string
+	ProfilerAddr     string
 	ResetDeltaIdxs   bool
 	Verbose          bool
 	// null duration means use default value
@@ -169,11 +169,11 @@ func (a *App) startup() error {
 		return err
 	}
 
-	if len(a.opts.ProfilerURL) > 0 {
+	if len(a.opts.ProfilerAddr) > 0 {
 		go func() {
-			l.Debugln("Starting profiler on", a.opts.ProfilerURL)
+			l.Debugln("Starting profiler on", a.opts.ProfilerAddr)
 			runtime.SetBlockProfileRate(1)
-			err := http.ListenAndServe(a.opts.ProfilerURL, nil)
+			err := http.ListenAndServe(a.opts.ProfilerAddr, nil)
 			if err != nil {
 				l.Warnln(err)
 				return