Merge branch 'infrastructure'

* infrastructure: cmd/stupgrades: Basic process metrics cmd/stcrashreceiver: Ignore patterns, improve metrics cmd/strelaypoolsrv: More compact response, improved metrics cmd/stdiscosrv: Add AMQP replication
2024-10-18 10:06:29 +00:00 · 2024-06-04 07:18:35 -04:00 · 2024-06-04 07:18:35 -04:00 · 21e0f98fe2
commit 21e0f98fe2
parent 495809ac9e 2bb5b2244b
18 changed files with 722 additions and 268 deletions
--- a/cmd/stcrashreceiver/main.go
+++ b/cmd/stcrashreceiver/main.go
@ -21,11 +21,14 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"regexp"
+	"strings"

 	"github.com/alecthomas/kong"
 	raven "github.com/getsentry/raven-go"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	_ "github.com/syncthing/syncthing/lib/automaxprocs"
+	"github.com/syncthing/syncthing/lib/build"
 	"github.com/syncthing/syncthing/lib/sha256"
 	"github.com/syncthing/syncthing/lib/ur"
 )
@ -33,13 +36,15 @@ import (
 const maxRequestSize = 1 << 20 // 1 MiB

 type cli struct {
-	Dir           string `help:"Parent directory to store crash and failure reports in" env:"REPORTS_DIR" default:"."`
-	DSN           string `help:"Sentry DSN" env:"SENTRY_DSN"`
-	Listen        string `help:"HTTP listen address" default:":8080" env:"LISTEN_ADDRESS"`
-	MaxDiskFiles  int    `help:"Maximum number of reports on disk" default:"100000" env:"MAX_DISK_FILES"`
-	MaxDiskSizeMB int64  `help:"Maximum disk space to use for reports" default:"1024" env:"MAX_DISK_SIZE_MB"`
-	SentryQueue   int    `help:"Maximum number of reports to queue for sending to Sentry" default:"64" env:"SENTRY_QUEUE"`
-	DiskQueue     int    `help:"Maximum number of reports to queue for writing to disk" default:"64" env:"DISK_QUEUE"`
+	Dir            string `help:"Parent directory to store crash and failure reports in" env:"REPORTS_DIR" default:"."`
+	DSN            string `help:"Sentry DSN" env:"SENTRY_DSN"`
+	Listen         string `help:"HTTP listen address" default:":8080" env:"LISTEN_ADDRESS"`
+	MaxDiskFiles   int    `help:"Maximum number of reports on disk" default:"100000" env:"MAX_DISK_FILES"`
+	MaxDiskSizeMB  int64  `help:"Maximum disk space to use for reports" default:"1024" env:"MAX_DISK_SIZE_MB"`
+	SentryQueue    int    `help:"Maximum number of reports to queue for sending to Sentry" default:"64" env:"SENTRY_QUEUE"`
+	DiskQueue      int    `help:"Maximum number of reports to queue for writing to disk" default:"64" env:"DISK_QUEUE"`
+	MetricsListen  string `help:"HTTP listen address for metrics" default:":8081" env:"METRICS_LISTEN_ADDRESS"`
+	IngorePatterns string `help:"File containing ignore patterns (regexp)" env:"IGNORE_PATTERNS" type:"existingfile"`
 }

 func main() {
@ -62,19 +67,38 @@ func main() {
 	}
 	go ss.Serve(context.Background())

+	var ip *ignorePatterns
+	if params.IngorePatterns != "" {
+		var err error
+		ip, err = loadIgnorePatterns(params.IngorePatterns)
+		if err != nil {
+			log.Fatalf("Failed to load ignore patterns: %v", err)
+		}
+	}
+
 	cr := &crashReceiver{
 		store:  ds,
 		sentry: ss,
+		ignore: ip,
 	}

 	mux.Handle("/", cr)
 	mux.HandleFunc("/ping", func(w http.ResponseWriter, req *http.Request) {
 		w.Write([]byte("OK"))
 	})
-	mux.Handle("/metrics", promhttp.Handler())
+
+	if params.MetricsListen != "" {
+		mmux := http.NewServeMux()
+		mmux.Handle("/metrics", promhttp.Handler())
+		go func() {
+			if err := http.ListenAndServe(params.MetricsListen, mmux); err != nil {
+				log.Fatalln("HTTP serve metrics:", err)
+			}
+		}()
+	}

 	if params.DSN != "" {
-		mux.HandleFunc("/newcrash/failure", handleFailureFn(params.DSN, filepath.Join(params.Dir, "failure_reports")))
+		mux.HandleFunc("/newcrash/failure", handleFailureFn(params.DSN, filepath.Join(params.Dir, "failure_reports"), ip))
 	}

 	log.SetOutput(os.Stdout)
@ -83,7 +107,7 @@ func main() {
 	}
 }

-func handleFailureFn(dsn, failureDir string) func(w http.ResponseWriter, req *http.Request) {
+func handleFailureFn(dsn, failureDir string, ignore *ignorePatterns) func(w http.ResponseWriter, req *http.Request) {
 	return func(w http.ResponseWriter, req *http.Request) {
 		result := "failure"
 		defer func() {
@ -98,6 +122,11 @@ func handleFailureFn(dsn, failureDir string) func(w http.ResponseWriter, req *ht
 			return
 		}

+		if ignore.match(bs) {
+			result = "ignored"
+			return
+		}
+
 		var reports []ur.FailureReport
 		err = json.Unmarshal(bs, &reports)
 		if err != nil {
@ -110,7 +139,7 @@ func handleFailureFn(dsn, failureDir string) func(w http.ResponseWriter, req *ht
 			return
 		}

-		version, err := parseVersion(reports[0].Version)
+		version, err := build.ParseVersion(reports[0].Version)
 		if err != nil {
 			http.Error(w, err.Error(), 400)
 			return
@ -158,3 +187,42 @@ func saveFailureWithGoroutines(data ur.FailureData, failureDir string) (string,
 	}
 	return reportServer + path, nil
 }
+
+type ignorePatterns struct {
+	patterns []*regexp.Regexp
+}
+
+func loadIgnorePatterns(path string) (*ignorePatterns, error) {
+	bs, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	var patterns []*regexp.Regexp
+	for _, line := range strings.Split(string(bs), "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" {
+			continue
+		}
+		re, err := regexp.Compile(line)
+		if err != nil {
+			return nil, err
+		}
+		patterns = append(patterns, re)
+	}
+
+	log.Printf("Loaded %d ignore patterns", len(patterns))
+	return &ignorePatterns{patterns: patterns}, nil
+}
+
+func (i *ignorePatterns) match(report []byte) bool {
+	if i == nil {
+		return false
+	}
+	for _, re := range i.patterns {
+		if re.Match(report) {
+			return true
+		}
+	}
+	return false
+}
--- a/cmd/stcrashreceiver/sentry.go
+++ b/cmd/stcrashreceiver/sentry.go
@ -18,6 +18,7 @@ import (

 	raven "github.com/getsentry/raven-go"
 	"github.com/maruel/panicparse/v2/stack"
+	"github.com/syncthing/syncthing/lib/build"
 )

 const reportServer = "https://crash.syncthing.net/report/"
@ -105,7 +106,7 @@ func parseCrashReport(path string, report []byte) (*raven.Packet, error) {
 		return nil, errors.New("no first line")
 	}

-	version, err := parseVersion(string(parts[0]))
+	version, err := build.ParseVersion(string(parts[0]))
 	if err != nil {
 		return nil, err
 	}
@ -143,12 +144,12 @@ func parseCrashReport(path string, report []byte) (*raven.Packet, error) {
 	}

 	// Lock the source code loader to the version we are processing here.
-	if version.commit != "" {
+	if version.Commit != "" {
 		// We have a commit hash, so we know exactly which source to use
-		loader.LockWithVersion(version.commit)
-	} else if strings.HasPrefix(version.tag, "v") {
+		loader.LockWithVersion(version.Commit)
+	} else if strings.HasPrefix(version.Tag, "v") {
 		// Lets hope the tag is close enough
-		loader.LockWithVersion(version.tag)
+		loader.LockWithVersion(version.Tag)
 	} else {
 		// Last resort
 		loader.LockWithVersion("main")
@ -215,106 +216,26 @@ func crashReportFingerprint(message string) []string {
 	return []string{"{{ default }}", message}
 }

-// syncthing v1.1.4-rc.1+30-g6aaae618-dirty-crashrep "Erbium Earthworm" (go1.12.5 darwin-amd64) jb@kvin.kastelo.net 2019-05-23 16:08:14 UTC [foo, bar]
-// or, somewhere along the way the "+" in the version tag disappeared:
-// syncthing v1.23.7-dev.26.gdf7b56ae.dirty-stversionextra "Fermium Flea" (go1.20.5 darwin-arm64) jb@ok.kastelo.net 2023-07-12 06:55:26 UTC [Some Wrapper, purego, stnoupgrade]
-var (
-	longVersionRE = regexp.MustCompile(`syncthing\s+(v[^\s]+)\s+"([^"]+)"\s\(([^\s]+)\s+([^-]+)-([^)]+)\)\s+([^\s]+)[^\[]*(?:\[(.+)\])?$`)
-	gitExtraRE    = regexp.MustCompile(`\.\d+\.g[0-9a-f]+`) // ".1.g6aaae618"
-	gitExtraSepRE = regexp.MustCompile(`[.-]`)              // dot or dash
-)
-
-type version struct {
-	version  string   // "v1.1.4-rc.1+30-g6aaae618-dirty-crashrep"
-	tag      string   // "v1.1.4-rc.1"
-	commit   string   // "6aaae618", blank when absent
-	codename string   // "Erbium Earthworm"
-	runtime  string   // "go1.12.5"
-	goos     string   // "darwin"
-	goarch   string   // "amd64"
-	builder  string   // "jb@kvin.kastelo.net"
-	extra    []string // "foo", "bar"
-}
-
-func (v version) environment() string {
-	if v.commit != "" {
-		return "Development"
-	}
-	if strings.Contains(v.tag, "-rc.") {
-		return "Candidate"
-	}
-	if strings.Contains(v.tag, "-") {
-		return "Beta"
-	}
-	return "Stable"
-}
-
-func parseVersion(line string) (version, error) {
-	m := longVersionRE.FindStringSubmatch(line)
-	if len(m) == 0 {
-		return version{}, errors.New("unintelligeble version string")
-	}
-
-	v := version{
-		version:  m[1],
-		codename: m[2],
-		runtime:  m[3],
-		goos:     m[4],
-		goarch:   m[5],
-		builder:  m[6],
-	}
-
-	// Split the version tag into tag and commit. This is old style
-	// v1.2.3-something.4+11-g12345678 or newer with just dots
-	// v1.2.3-something.4.11.g12345678 or v1.2.3-dev.11.g12345678.
-	parts := []string{v.version}
-	if strings.Contains(v.version, "+") {
-		parts = strings.Split(v.version, "+")
-	} else {
-		idxs := gitExtraRE.FindStringIndex(v.version)
-		if len(idxs) > 0 {
-			parts = []string{v.version[:idxs[0]], v.version[idxs[0]+1:]}
-		}
-	}
-	v.tag = parts[0]
-	if len(parts) > 1 {
-		fields := gitExtraSepRE.Split(parts[1], -1)
-		if len(fields) >= 2 && strings.HasPrefix(fields[1], "g") {
-			v.commit = fields[1][1:]
-		}
-	}
-
-	if len(m) >= 8 && m[7] != "" {
-		tags := strings.Split(m[7], ",")
-		for i := range tags {
-			tags[i] = strings.TrimSpace(tags[i])
-		}
-		v.extra = tags
-	}
-
-	return v, nil
-}
-
-func packet(version version, reportType string) *raven.Packet {
+func packet(version build.VersionParts, reportType string) *raven.Packet {
 	pkt := &raven.Packet{
 		Platform:    "go",
-		Release:     version.tag,
-		Environment: version.environment(),
+		Release:     version.Tag,
+		Environment: version.Environment(),
 		Tags: raven.Tags{
-			raven.Tag{Key: "version", Value: version.version},
-			raven.Tag{Key: "tag", Value: version.tag},
-			raven.Tag{Key: "codename", Value: version.codename},
-			raven.Tag{Key: "runtime", Value: version.runtime},
-			raven.Tag{Key: "goos", Value: version.goos},
-			raven.Tag{Key: "goarch", Value: version.goarch},
-			raven.Tag{Key: "builder", Value: version.builder},
+			raven.Tag{Key: "version", Value: version.Version},
+			raven.Tag{Key: "tag", Value: version.Tag},
+			raven.Tag{Key: "codename", Value: version.Codename},
+			raven.Tag{Key: "runtime", Value: version.Runtime},
+			raven.Tag{Key: "goos", Value: version.GOOS},
+			raven.Tag{Key: "goarch", Value: version.GOARCH},
+			raven.Tag{Key: "builder", Value: version.Builder},
 			raven.Tag{Key: "report_type", Value: reportType},
 		},
 	}
-	if version.commit != "" {
-		pkt.Tags = append(pkt.Tags, raven.Tag{Key: "commit", Value: version.commit})
+	if version.Commit != "" {
+		pkt.Tags = append(pkt.Tags, raven.Tag{Key: "commit", Value: version.Commit})
 	}
-	for _, tag := range version.extra {
+	for _, tag := range version.Extra {
 		pkt.Tags = append(pkt.Tags, raven.Tag{Key: tag, Value: "1"})
 	}
 	return pkt
--- a/cmd/stcrashreceiver/sentry_test.go
+++ b/cmd/stcrashreceiver/sentry_test.go
@ -12,66 +12,6 @@ import (
 	"testing"
 )

-func TestParseVersion(t *testing.T) {
-	cases := []struct {
-		longVersion string
-		parsed      version
-	}{
-		{
-			longVersion: `syncthing v1.1.4-rc.1+30-g6aaae618-dirty-crashrep "Erbium Earthworm" (go1.12.5 darwin-amd64) jb@kvin.kastelo.net 2019-05-23 16:08:14 UTC`,
-			parsed: version{
-				version:  "v1.1.4-rc.1+30-g6aaae618-dirty-crashrep",
-				tag:      "v1.1.4-rc.1",
-				commit:   "6aaae618",
-				codename: "Erbium Earthworm",
-				runtime:  "go1.12.5",
-				goos:     "darwin",
-				goarch:   "amd64",
-				builder:  "jb@kvin.kastelo.net",
-			},
-		},
-		{
-			longVersion: `syncthing v1.1.4-rc.1+30-g6aaae618-dirty-crashrep "Erbium Earthworm" (go1.12.5 darwin-amd64) jb@kvin.kastelo.net 2019-05-23 16:08:14 UTC [foo, bar]`,
-			parsed: version{
-				version:  "v1.1.4-rc.1+30-g6aaae618-dirty-crashrep",
-				tag:      "v1.1.4-rc.1",
-				commit:   "6aaae618",
-				codename: "Erbium Earthworm",
-				runtime:  "go1.12.5",
-				goos:     "darwin",
-				goarch:   "amd64",
-				builder:  "jb@kvin.kastelo.net",
-				extra:    []string{"foo", "bar"},
-			},
-		},
-		{
-			longVersion: `syncthing v1.23.7-dev.26.gdf7b56ae-stversionextra "Fermium Flea" (go1.20.5 darwin-arm64) jb@ok.kastelo.net 2023-07-12 06:55:26 UTC [Some Wrapper, purego, stnoupgrade]`,
-			parsed: version{
-				version:  "v1.23.7-dev.26.gdf7b56ae-stversionextra",
-				tag:      "v1.23.7-dev",
-				commit:   "df7b56ae",
-				codename: "Fermium Flea",
-				runtime:  "go1.20.5",
-				goos:     "darwin",
-				goarch:   "arm64",
-				builder:  "jb@ok.kastelo.net",
-				extra:    []string{"Some Wrapper", "purego", "stnoupgrade"},
-			},
-		},
-	}
-
-	for _, tc := range cases {
-		v, err := parseVersion(tc.longVersion)
-		if err != nil {
-			t.Errorf("%s\nerror: %v\n", tc.longVersion, err)
-			continue
-		}
-		if fmt.Sprint(v) != fmt.Sprint(tc.parsed) {
-			t.Errorf("%s\nA: %v\nE: %v\n", tc.longVersion, v, tc.parsed)
-		}
-	}
-}
-
 func TestParseReport(t *testing.T) {
 	bs, err := os.ReadFile("_testdata/panic.log")
 	if err != nil {
--- a/cmd/stcrashreceiver/stcrashreceiver.go
+++ b/cmd/stcrashreceiver/stcrashreceiver.go
@ -12,11 +12,16 @@ import (
 	"net/http"
 	"path"
 	"strings"
+	"sync"
 )

 type crashReceiver struct {
 	store  *diskStore
 	sentry *sentryService
+	ignore *ignorePatterns
+
+	ignoredMut sync.RWMutex
+	ignored    map[string]struct{}
 }

 func (r *crashReceiver) ServeHTTP(w http.ResponseWriter, req *http.Request) {
@ -64,6 +69,12 @@ func (r *crashReceiver) serveGet(reportID string, w http.ResponseWriter, _ *http
 // serveHead responds to HEAD requests by checking if the named report
 // already exists in the system.
 func (r *crashReceiver) serveHead(reportID string, w http.ResponseWriter, _ *http.Request) {
+	r.ignoredMut.RLock()
+	_, ignored := r.ignored[reportID]
+	r.ignoredMut.RUnlock()
+	if ignored {
+		return // found
+	}
 	if !r.store.Exists(reportID) {
 		http.Error(w, "Not found", http.StatusNotFound)
 	}
@ -76,6 +87,15 @@ func (r *crashReceiver) servePut(reportID string, w http.ResponseWriter, req *ht
 		metricCrashReportsTotal.WithLabelValues(result).Inc()
 	}()

+	r.ignoredMut.RLock()
+	_, ignored := r.ignored[reportID]
+	r.ignoredMut.RUnlock()
+	if ignored {
+		result = "ignored_cached"
+		io.Copy(io.Discard, req.Body)
+		return // found
+	}
+
 	// Read at most maxRequestSize of report data.
 	log.Println("Receiving report", reportID)
 	lr := io.LimitReader(req.Body, maxRequestSize)
@ -86,6 +106,17 @@ func (r *crashReceiver) servePut(reportID string, w http.ResponseWriter, req *ht
 		return
 	}

+	if r.ignore.match(bs) {
+		r.ignoredMut.Lock()
+		if r.ignored == nil {
+			r.ignored = make(map[string]struct{})
+		}
+		r.ignored[reportID] = struct{}{}
+		r.ignoredMut.Unlock()
+		result = "ignored"
+		return
+	}
+
 	result = "success"

 	// Store the report
--- a/cmd/stdiscosrv/amqp.go
+++ b/cmd/stdiscosrv/amqp.go
@ -0,0 +1,246 @@
+// Copyright (C) 2024 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 (
+	"context"
+	"fmt"
+	"io"
+
+	amqp "github.com/rabbitmq/amqp091-go"
+	"github.com/thejerf/suture/v4"
+)
+
+type amqpReplicator struct {
+	suture.Service
+	broker   string
+	sender   *amqpSender
+	receiver *amqpReceiver
+	outbox   chan ReplicationRecord
+}
+
+func newAMQPReplicator(broker, clientID string, db database) *amqpReplicator {
+	svc := suture.New("amqpReplicator", suture.Spec{PassThroughPanics: true})
+
+	sender := &amqpSender{
+		broker:   broker,
+		clientID: clientID,
+		outbox:   make(chan ReplicationRecord, replicationOutboxSize),
+	}
+	svc.Add(sender)
+
+	receiver := &amqpReceiver{
+		broker:   broker,
+		clientID: clientID,
+		db:       db,
+	}
+	svc.Add(receiver)
+
+	return &amqpReplicator{
+		Service:  svc,
+		broker:   broker,
+		sender:   sender,
+		receiver: receiver,
+		outbox:   make(chan ReplicationRecord, replicationOutboxSize),
+	}
+}
+
+func (s *amqpReplicator) send(key string, ps []DatabaseAddress, seen int64) {
+	s.sender.send(key, ps, seen)
+}
+
+type amqpSender struct {
+	broker   string
+	clientID string
+	outbox   chan ReplicationRecord
+}
+
+func (s *amqpSender) Serve(ctx context.Context) error {
+	conn, ch, err := amqpChannel(s.broker)
+	if err != nil {
+		return err
+	}
+	defer ch.Close()
+	defer conn.Close()
+
+	buf := make([]byte, 1024)
+	for {
+		select {
+		case rec := <-s.outbox:
+			size := rec.Size()
+			if len(buf) < size {
+				buf = make([]byte, size)
+			}
+
+			n, err := rec.MarshalTo(buf)
+			if err != nil {
+				replicationSendsTotal.WithLabelValues("error").Inc()
+				return fmt.Errorf("replication marshal: %w", err)
+			}
+
+			err = ch.PublishWithContext(ctx,
+				"discovery", // exchange
+				"",          // routing key
+				false,       // mandatory
+				false,       // immediate
+				amqp.Publishing{
+					ContentType: "application/protobuf",
+					Body:        buf[:n],
+					AppId:       s.clientID,
+				})
+			if err != nil {
+				replicationSendsTotal.WithLabelValues("error").Inc()
+				return fmt.Errorf("replication publish: %w", err)
+			}
+
+			replicationSendsTotal.WithLabelValues("success").Inc()
+
+		case <-ctx.Done():
+			return nil
+		}
+	}
+}
+
+func (s *amqpSender) String() string {
+	return fmt.Sprintf("amqpSender(%q)", s.broker)
+}
+
+func (s *amqpSender) send(key string, ps []DatabaseAddress, seen int64) {
+	item := ReplicationRecord{
+		Key:       key,
+		Addresses: ps,
+		Seen:      seen,
+	}
+
+	// The send should never block. The inbox is suitably buffered for at
+	// least a few seconds of stalls, which shouldn't happen in practice.
+	select {
+	case s.outbox <- item:
+	default:
+		replicationSendsTotal.WithLabelValues("drop").Inc()
+	}
+}
+
+type amqpReceiver struct {
+	broker   string
+	clientID string
+	db       database
+}
+
+func (s *amqpReceiver) Serve(ctx context.Context) error {
+	conn, ch, err := amqpChannel(s.broker)
+	if err != nil {
+		return err
+	}
+	defer ch.Close()
+	defer conn.Close()
+
+	msgs, err := amqpConsume(ch)
+	if err != nil {
+		return err
+	}
+
+	for {
+		select {
+		case msg, ok := <-msgs:
+			if !ok {
+				return fmt.Errorf("subscription closed: %w", io.EOF)
+			}
+
+			// ignore messages from ourself
+			if msg.AppId == s.clientID {
+				continue
+			}
+
+			var rec ReplicationRecord
+			if err := rec.Unmarshal(msg.Body); err != nil {
+				replicationRecvsTotal.WithLabelValues("error").Inc()
+				return fmt.Errorf("replication unmarshal: %w", err)
+			}
+
+			if err := s.db.merge(rec.Key, rec.Addresses, rec.Seen); err != nil {
+				return fmt.Errorf("replication database merge: %w", err)
+			}
+
+			replicationRecvsTotal.WithLabelValues("success").Inc()
+
+		case <-ctx.Done():
+			return nil
+		}
+	}
+}
+
+func (s *amqpReceiver) String() string {
+	return fmt.Sprintf("amqpReceiver(%q)", s.broker)
+}
+
+func amqpChannel(dst string) (*amqp.Connection, *amqp.Channel, error) {
+	conn, err := amqp.Dial(dst)
+	if err != nil {
+		return nil, nil, fmt.Errorf("AMQP dial: %w", err)
+	}
+
+	ch, err := conn.Channel()
+	if err != nil {
+		return nil, nil, fmt.Errorf("AMQP channel: %w", err)
+	}
+
+	err = ch.ExchangeDeclare(
+		"discovery", // name
+		"fanout",    // type
+		false,       // durable
+		false,       // auto-deleted
+		false,       // internal
+		false,       // no-wait
+		nil,         // arguments
+	)
+	if err != nil {
+		return nil, nil, fmt.Errorf("AMQP declare exchange: %w", err)
+	}
+
+	return conn, ch, nil
+}
+
+func amqpConsume(ch *amqp.Channel) (<-chan amqp.Delivery, error) {
+	q, err := ch.QueueDeclare(
+		"",    // name
+		false, // durable
+		false, // delete when unused
+		true,  // exclusive
+		false, // no-wait
+		nil,   // arguments
+	)
+	if err != nil {
+		return nil, fmt.Errorf("AMQP declare queue: %w", err)
+	}
+
+	err = ch.QueueBind(
+		q.Name,      // queue name
+		"",          // routing key
+		"discovery", // exchange
+		false,
+		nil,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("AMQP bind queue: %w", err)
+	}
+
+	msgs, err := ch.Consume(
+		q.Name, // queue
+		"",     // consumer
+		true,   // auto-ack
+		false,  // exclusive
+		false,  // no-local
+		false,  // no-wait
+		nil,    // args
+	)
+	if err != nil {
+		return nil, fmt.Errorf("AMQP consume: %w", err)
+	}
+
+	return msgs, nil
+}
--- a/cmd/stdiscosrv/apisrv.go
+++ b/cmd/stdiscosrv/apisrv.go
@ -39,12 +39,13 @@ type announcement struct {
 }

 type apiSrv struct {
-	addr     string
-	cert     tls.Certificate
-	db       database
-	listener net.Listener
-	repl     replicator // optional
-	useHTTP  bool
+	addr           string
+	cert           tls.Certificate
+	db             database
+	listener       net.Listener
+	repl           replicator // optional
+	useHTTP        bool
+	missesIncrease int

 	mapsMut sync.Mutex
 	misses  map[string]int32
@ -60,14 +61,15 @@ type contextKey int

 const idKey contextKey = iota

-func newAPISrv(addr string, cert tls.Certificate, db database, repl replicator, useHTTP bool) *apiSrv {
+func newAPISrv(addr string, cert tls.Certificate, db database, repl replicator, useHTTP bool, missesIncrease int) *apiSrv {
 	return &apiSrv{
-		addr:    addr,
-		cert:    cert,
-		db:      db,
-		repl:    repl,
-		useHTTP: useHTTP,
-		misses:  make(map[string]int32),
+		addr:           addr,
+		cert:           cert,
+		db:             db,
+		repl:           repl,
+		useHTTP:        useHTTP,
+		misses:         make(map[string]int32),
+		missesIncrease: missesIncrease,
 	}
 }

@ -197,14 +199,13 @@ func (s *apiSrv) handleGET(w http.ResponseWriter, req *http.Request) {
 		s.mapsMut.Lock()
 		misses := s.misses[key]
 		if misses < rec.Misses {
-			misses = rec.Misses + 1
-		} else {
-			misses++
+			misses = rec.Misses
 		}
+		misses += int32(s.missesIncrease)
 		s.misses[key] = misses
 		s.mapsMut.Unlock()

-		if misses%notFoundMissesWriteInterval == 0 {
+		if misses >= notFoundMissesWriteInterval {
 			rec.Misses = misses
 			rec.Missed = time.Now().UnixNano()
 			rec.Addresses = nil
@ -444,7 +445,6 @@ func fixupAddresses(remote *net.TCPAddr, addresses []string) []string {
 				// remote is nil, unable to determine host IP
 				continue
 			}
-
 		}

 		// If zero port was specified, use remote port.
--- a/cmd/stdiscosrv/main.go
+++ b/cmd/stdiscosrv/main.go
@ -22,6 +22,7 @@ import (
 	_ "github.com/syncthing/syncthing/lib/automaxprocs"
 	"github.com/syncthing/syncthing/lib/build"
 	"github.com/syncthing/syncthing/lib/protocol"
+	"github.com/syncthing/syncthing/lib/rand"
 	"github.com/syncthing/syncthing/lib/tlsutil"
 	"github.com/syndtr/goleveldb/leveldb/opt"
 	"github.com/thejerf/suture/v4"
@ -80,6 +81,8 @@ func main() {
 	var replKeyFile string
 	var useHTTP bool
 	var largeDB bool
+	var amqpAddress string
+	missesIncrease := 1

 	log.SetOutput(os.Stdout)
 	log.SetFlags(0)
@ -96,6 +99,8 @@ func main() {
 	flag.StringVar(&replCertFile, "replication-cert", "", "Certificate file for replication")
 	flag.StringVar(&replKeyFile, "replication-key", "", "Key file for replication")
 	flag.BoolVar(&largeDB, "large-db", false, "Use larger database settings")
+	flag.StringVar(&amqpAddress, "amqp-address", "", "Address to AMQP broker")
+	flag.IntVar(&missesIncrease, "misses-increase", 1, "How many times to increase the misses counter on each miss")
 	showVersion := flag.Bool("version", false, "Show version")
 	flag.Parse()

@ -203,8 +208,24 @@ func main() {
 		main.Add(rl)
 	}

+	// If we have an AMQP broker, start that
+	if amqpAddress != "" {
+		clientID := rand.String(10)
+		kr := newAMQPReplicator(amqpAddress, clientID, db)
+		repl = append(repl, kr)
+		main.Add(kr)
+	}
+
+	go func() {
+		for range time.NewTicker(time.Second).C {
+			for _, r := range repl {
+				r.send("<heartbeat>", nil, time.Now().UnixNano())
+			}
+		}
+	}()
+
 	// Start the main API server.
-	qs := newAPISrv(listen, cert, db, repl, useHTTP)
+	qs := newAPISrv(listen, cert, db, repl, useHTTP, missesIncrease)
 	main.Add(qs)

 	// If we have a metrics port configured, start a metrics handler.
--- a/cmd/stdiscosrv/replication.go
+++ b/cmd/stdiscosrv/replication.go
@ -144,10 +144,11 @@ func (s *replicationSender) String() string {
 	return fmt.Sprintf("replicationSender(%q)", s.dst)
 }

-func (s *replicationSender) send(key string, ps []DatabaseAddress, _ int64) {
+func (s *replicationSender) send(key string, ps []DatabaseAddress, seen int64) {
 	item := ReplicationRecord{
 		Key:       key,
 		Addresses: ps,
+		Seen:      seen,
 	}

 	// The send should never block. The inbox is suitably buffered for at
--- a/cmd/stdiscosrv/stats.go
+++ b/cmd/stdiscosrv/stats.go
@ -7,10 +7,7 @@
 package main

 import (
-	"os"
-
 	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/collectors"
 )

 var (
@ -127,15 +124,4 @@ func init() {
 		databaseKeys, databaseStatisticsSeconds,
 		databaseOperations, databaseOperationSeconds,
 		retryAfterHistogram)
-
-	processCollectorOpts := collectors.ProcessCollectorOpts{
-		Namespace: "syncthing_discovery",
-		PidFn: func() (int, error) {
-			return os.Getpid(), nil
-		},
-	}
-
-	prometheus.MustRegister(
-		collectors.NewProcessCollector(processCollectorOpts),
-	)
 }
--- a/cmd/strelaypoolsrv/gui/index.html
+++ b/cmd/strelaypoolsrv/gui/index.html
@ -259,7 +259,7 @@
      return a.value > b.value ? 1 : -1;
    }

-    $http.get("/endpoint").then(function(response) {
+    $http.get("/endpoint/full").then(function(response) {
      $scope.relays = response.data.relays;

      angular.forEach($scope.relays, function(relay) {
--- a/cmd/strelaypoolsrv/main.go
+++ b/cmd/strelaypoolsrv/main.go
@ -27,9 +27,7 @@ import (
 	"github.com/syncthing/syncthing/lib/assets"
 	_ "github.com/syncthing/syncthing/lib/automaxprocs"
 	"github.com/syncthing/syncthing/lib/geoip"
-	"github.com/syncthing/syncthing/lib/httpcache"
 	"github.com/syncthing/syncthing/lib/protocol"
-	"github.com/syncthing/syncthing/lib/rand"
 	"github.com/syncthing/syncthing/lib/relay/client"
 	"github.com/syncthing/syncthing/lib/sync"
 	"github.com/syncthing/syncthing/lib/tlsutil"
@ -51,6 +49,10 @@ type relay struct {
 	StatsRetrieved time.Time `json:"statsRetrieved"`
 }

+type relayShort struct {
+	URL string `json:"url"`
+}
+
 type stats struct {
 	StartTime          time.Time `json:"startTime"`
 	UptimeSeconds      int       `json:"uptimeSeconds"`
@ -95,6 +97,7 @@ var (
 	testCert          tls.Certificate
 	knownRelaysFile   = filepath.Join(os.TempDir(), "strelaypoolsrv_known_relays")
 	listen            = ":80"
+	metricsListen     = ":8081"
 	dir               string
 	evictionTime      = time.Hour
 	debug             bool
@ -125,6 +128,7 @@ func main() {
 	log.SetFlags(log.Lshortfile)

 	flag.StringVar(&listen, "listen", listen, "Listen address")
+	flag.StringVar(&metricsListen, "metrics-listen", metricsListen, "Metrics listen address")
 	flag.StringVar(&dir, "keys", dir, "Directory where http-cert.pem and http-key.pem is stored for TLS listening")
 	flag.BoolVar(&debug, "debug", debug, "Enable debug output")
 	flag.DurationVar(&evictionTime, "eviction", evictionTime, "After how long the relay is evicted")
@ -218,15 +222,40 @@ func main() {
 		log.Fatalln("listen:", err)
 	}

-	handler := http.NewServeMux()
-	handler.HandleFunc("/", handleAssets)
-	handler.Handle("/endpoint", httpcache.SinglePath(http.HandlerFunc(handleRequest), 15*time.Second))
-	handler.HandleFunc("/metrics", handleMetrics)
+	if metricsListen != "" {
+		mmux := http.NewServeMux()
+		mmux.HandleFunc("/metrics", handleMetrics)
+		go func() {
+			if err := http.ListenAndServe(metricsListen, mmux); err != nil {
+				log.Fatalln("HTTP serve metrics:", err)
+			}
+		}()
+	}
+
+	getMux := http.NewServeMux()
+	getMux.HandleFunc("/", handleAssets)
+	getMux.HandleFunc("/endpoint", withAPIMetrics(handleEndpointShort))
+	getMux.HandleFunc("/endpoint/full", withAPIMetrics(handleEndpointFull))
+
+	postMux := http.NewServeMux()
+	postMux.HandleFunc("/endpoint", withAPIMetrics(handleRegister))
+
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.Method {
+		case http.MethodGet, http.MethodHead, http.MethodOptions:
+			getMux.ServeHTTP(w, r)
+		case http.MethodPost:
+			postMux.ServeHTTP(w, r)
+		default:
+			http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		}
+	})

 	srv := http.Server{
 		Handler:     handler,
 		ReadTimeout: 10 * time.Second,
 	}
+	srv.SetKeepAlivesEnabled(false)

 	err = srv.Serve(listener)
 	if err != nil {
@ -260,39 +289,24 @@ func handleAssets(w http.ResponseWriter, r *http.Request) {
 	assets.Serve(w, r, as)
 }

-func handleRequest(w http.ResponseWriter, r *http.Request) {
-	timer := prometheus.NewTimer(apiRequestsSeconds.WithLabelValues(r.Method))
-
-	w = NewLoggingResponseWriter(w)
-	defer func() {
-		timer.ObserveDuration()
-		lw := w.(*loggingResponseWriter)
-		apiRequestsTotal.WithLabelValues(r.Method, strconv.Itoa(lw.statusCode)).Inc()
-	}()
-
-	if ipHeader != "" {
-		hdr := r.Header.Get(ipHeader)
-		fields := strings.Split(hdr, ",")
-		if len(fields) > 0 {
-			r.RemoteAddr = strings.TrimSpace(fields[len(fields)-1])
-		}
-	}
-	w.Header().Set("Access-Control-Allow-Origin", "*")
-	switch r.Method {
-	case "GET":
-		handleGetRequest(w, r)
-	case "POST":
-		handlePostRequest(w, r)
-	default:
-		if debug {
-			log.Println("Unhandled HTTP method", r.Method)
-		}
-		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+func withAPIMetrics(next http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		timer := prometheus.NewTimer(apiRequestsSeconds.WithLabelValues(r.Method))
+		w = NewLoggingResponseWriter(w)
+		defer func() {
+			timer.ObserveDuration()
+			lw := w.(*loggingResponseWriter)
+			apiRequestsTotal.WithLabelValues(r.Method, strconv.Itoa(lw.statusCode)).Inc()
+		}()
+		next(w, r)
 	}
 }

-func handleGetRequest(rw http.ResponseWriter, r *http.Request) {
+// handleEndpointFull returns the relay list with full metadata and
+// statistics. Large, and expensive.
+func handleEndpointFull(rw http.ResponseWriter, r *http.Request) {
 	rw.Header().Set("Content-Type", "application/json; charset=utf-8")
+	rw.Header().Set("Access-Control-Allow-Origin", "*")

 	mut.RLock()
 	relays := make([]*relay, len(permanentRelays)+len(knownRelays))
@ -300,17 +314,38 @@ func handleGetRequest(rw http.ResponseWriter, r *http.Request) {
 	copy(relays[n:], knownRelays)
 	mut.RUnlock()

-	// Shuffle
-	rand.Shuffle(relays)
-
 	_ = json.NewEncoder(rw).Encode(map[string][]*relay{
 		"relays": relays,
 	})
 }

-func handlePostRequest(w http.ResponseWriter, r *http.Request) {
+// handleEndpointShort returns the relay list with only the URL.
+func handleEndpointShort(rw http.ResponseWriter, r *http.Request) {
+	rw.Header().Set("Content-Type", "application/json; charset=utf-8")
+	rw.Header().Set("Access-Control-Allow-Origin", "*")
+
+	mut.RLock()
+	relays := make([]relayShort, 0, len(permanentRelays)+len(knownRelays))
+	for _, r := range append(permanentRelays, knownRelays...) {
+		relays = append(relays, relayShort{URL: slimURL(r.URL)})
+	}
+	mut.RUnlock()
+
+	_ = json.NewEncoder(rw).Encode(map[string][]relayShort{
+		"relays": relays,
+	})
+}
+
+func handleRegister(w http.ResponseWriter, r *http.Request) {
 	// Get the IP address of the client
 	rhost := r.RemoteAddr
+	if ipHeader != "" {
+		hdr := r.Header.Get(ipHeader)
+		fields := strings.Split(hdr, ",")
+		if len(fields) > 0 {
+			rhost = strings.TrimSpace(fields[len(fields)-1])
+		}
+	}
 	if host, _, err := net.SplitHostPort(rhost); err == nil {
 		rhost = host
 	}
@ -660,3 +695,16 @@ func (b *errorTracker) IsBlocked(host string) bool {
 	}
 	return false
 }
+
+func slimURL(u string) string {
+	p, err := url.Parse(u)
+	if err != nil {
+		return u
+	}
+	newQuery := url.Values{}
+	if id := p.Query().Get("id"); id != "" {
+		newQuery.Set("id", id)
+	}
+	p.RawQuery = newQuery.Encode()
+	return p.String()
+}
--- a/cmd/strelaypoolsrv/main_test.go
+++ b/cmd/strelaypoolsrv/main_test.go
@ -42,7 +42,7 @@ func TestHandleGetRequest(t *testing.T) {

 	w := httptest.NewRecorder()
 	w.Body = new(bytes.Buffer)
-	handleGetRequest(w, httptest.NewRequest("GET", "/", nil))
+	handleEndpointFull(w, httptest.NewRequest("GET", "/", nil))

 	result := make(map[string][]*relay)
 	err := json.NewDecoder(w.Body).Decode(&result)
@ -92,3 +92,18 @@ func TestCanonicalizeQueryValues(t *testing.T) {
 		t.Errorf("expected %q, got %q", exp, str)
 	}
 }
+
+func TestSlimURL(t *testing.T) {
+	cases := []struct {
+		in, out string
+	}{
+		{"http://example.com/", "http://example.com/"},
+		{"relay://192.0.2.42:22067/?globalLimitBps=0&id=EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M&networkTimeout=2m0s&pingInterval=1m0s&providedBy=Test&sessionLimitBps=0&statusAddr=%3A22070", "relay://192.0.2.42:22067/?id=EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M"},
+	}
+
+	for _, c := range cases {
+		if got := slimURL(c.in); got != c.out {
+			t.Errorf("expected %q, got %q", c.out, got)
+		}
+	}
+}
--- a/cmd/strelaypoolsrv/stats.go
+++ b/cmd/strelaypoolsrv/stats.go
@ -6,27 +6,12 @@ import (
 	"encoding/json"
 	"net"
 	"net/http"
-	"os"
 	"time"

 	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/syncthing/syncthing/lib/sync"
 )

-func init() {
-	processCollectorOpts := collectors.ProcessCollectorOpts{
-		Namespace: "syncthing_relaypoolsrv",
-		PidFn: func() (int, error) {
-			return os.Getpid(), nil
-		},
-	}
-
-	prometheus.MustRegister(
-		collectors.NewProcessCollector(processCollectorOpts),
-	)
-}
-
 var (
 	statusClient = http.Client{
 		Timeout: 5 * time.Second,
--- a/cmd/stupgrades/main.go
+++ b/cmd/stupgrades/main.go
@ -19,16 +19,18 @@ import (
 	"time"

 	"github.com/alecthomas/kong"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	_ "github.com/syncthing/syncthing/lib/automaxprocs"
 	"github.com/syncthing/syncthing/lib/httpcache"
 	"github.com/syncthing/syncthing/lib/upgrade"
 )

 type cli struct {
-	Listen    string        `default:":8080" help:"Listen address"`
-	URL       string        `short:"u" default:"https://api.github.com/repos/syncthing/syncthing/releases?per_page=25" help:"GitHub releases url"`
-	Forward   []string      `short:"f" help:"Forwarded pages, format: /path->https://example/com/url"`
-	CacheTime time.Duration `default:"15m" help:"Cache time"`
+	Listen        string        `default:":8080" help:"Listen address"`
+	MetricsListen string        `default:":8081" help:"Listen address for metrics"`
+	URL           string        `short:"u" default:"https://api.github.com/repos/syncthing/syncthing/releases?per_page=25" help:"GitHub releases url"`
+	Forward       []string      `short:"f" help:"Forwarded pages, format: /path->https://example/com/url"`
+	CacheTime     time.Duration `default:"15m" help:"Cache time"`
 }

 func main() {
@ -41,17 +43,37 @@ func main() {
 }

 func server(params *cli) error {
-	http.Handle("/meta.json", httpcache.SinglePath(&githubReleases{url: params.URL}, params.CacheTime))
+	if params.MetricsListen != "" {
+		mux := http.NewServeMux()
+		mux.Handle("/metrics", promhttp.Handler())
+		go func() {
+			log.Println("Listening for metrics on", params.MetricsListen)
+			if err := http.ListenAndServe(params.MetricsListen, mux); err != nil {
+				log.Fatalf("Failed to start metrics server: %v", err)
+			}
+		}()
+	}
+
+	mux := http.NewServeMux()
+	mux.Handle("/meta.json", httpcache.SinglePath(&githubReleases{url: params.URL}, params.CacheTime))

 	for _, fwd := range params.Forward {
 		path, url, ok := strings.Cut(fwd, "->")
 		if !ok {
 			return fmt.Errorf("invalid forward: %q", fwd)
 		}
-		http.Handle(path, httpcache.SinglePath(&proxy{url: url}, params.CacheTime))
+		log.Println("Forwarding", path, "to", url)
+		mux.Handle(path, httpcache.SinglePath(&proxy{url: url}, params.CacheTime))
 	}

-	return http.ListenAndServe(params.Listen, nil)
+	srv := &http.Server{
+		Addr:         params.Listen,
+		Handler:      mux,
+		ReadTimeout:  5 * time.Second,
+		WriteTimeout: 10 * time.Second,
+	}
+	srv.SetKeepAlivesEnabled(false)
+	return srv.ListenAndServe()
 }

 type githubReleases struct {
--- a/go.mod
+++ b/go.mod
@ -31,6 +31,7 @@ require (
 	github.com/pierrec/lz4/v4 v4.1.21
 	github.com/prometheus/client_golang v1.19.1
 	github.com/quic-go/quic-go v0.44.0
+	github.com/rabbitmq/amqp091-go v1.10.0
 	github.com/rcrowley/go-metrics v0.0.0-20201227073835-cf1acfcdf475
 	github.com/shirou/gopsutil/v3 v3.24.4
 	github.com/syncthing/notify v0.0.0-20210616190510-c6b7342338d2
--- a/go.sum
+++ b/go.sum
@ -200,6 +200,8 @@ github.com/prometheus/procfs v0.15.0 h1:A82kmvXJq2jTu5YUhSGNlYoxh85zLnKgPz4bMZgI
 github.com/prometheus/procfs v0.15.0/go.mod h1:Y0RJ/Y5g5wJpkTisOtqwDSo4HwhGmLB4VQSw2sQJLHk=
 github.com/quic-go/quic-go v0.44.0 h1:So5wOr7jyO4vzL2sd8/pD9Kesciv91zSk8BoFngItQ0=
 github.com/quic-go/quic-go v0.44.0/go.mod h1:z4cx/9Ny9UtGITIPzmPTXh1ULfOyWh4qGQlpnPcWmek=
+github.com/rabbitmq/amqp091-go v1.10.0 h1:STpn5XsHlHGcecLmMFCtg7mqq0RnD+zFr4uzukfVhBw=
+github.com/rabbitmq/amqp091-go v1.10.0/go.mod h1:Hy4jKW5kQART1u+JkDTF9YYOQUHXqMuhrgxOEeS7G4o=
 github.com/rcrowley/go-metrics v0.0.0-20201227073835-cf1acfcdf475 h1:N/ElC8H3+5XpJzTSTfLsJV/mx9Q9g7kxmchpfZyxgzM=
 github.com/rcrowley/go-metrics v0.0.0-20201227073835-cf1acfcdf475/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
 github.com/riywo/loginshell v0.0.0-20200815045211-7d26008be1ab h1:ZjX6I48eZSFetPb41dHudEyVr5v953N15TsNZXlkcWY=
@ -250,6 +252,8 @@ github.com/yusufpapurcu/wmi v1.2.4 h1:zFUKzehAFReQwLys1b/iSMl+JQGSCSjtVqQn9bBrPo
 github.com/yusufpapurcu/wmi v1.2.4/go.mod h1:SBZ9tNy3G9/m5Oi98Zks0QjeHVDvuK0qfxQmPyzfmi0=
 go.uber.org/automaxprocs v1.5.3 h1:kWazyxZUrS3Gs4qUpbwo5kEIMGe/DAvi5Z4tl2NW4j8=
 go.uber.org/automaxprocs v1.5.3/go.mod h1:eRbA25aqJrxAbsLO0xy5jVwPt7FQnRgjW+efnwa1WM0=
+go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
+go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 go.uber.org/mock v0.4.0 h1:VcM4ZOtdbR4f6VXfiOpwpVJDL6lCReaZ6mw31wqh7KU=
 go.uber.org/mock v0.4.0/go.mod h1:a6FSlNadKUHUa9IP5Vyt1zh4fC7uAwxMutEAscFbkZc=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
--- a/lib/build/parse.go
+++ b/lib/build/parse.go
@ -0,0 +1,93 @@
+// Copyright (C) 2019 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 build
+
+import (
+	"errors"
+	"regexp"
+	"strings"
+)
+
+// syncthing v1.1.4-rc.1+30-g6aaae618-dirty-crashrep "Erbium Earthworm" (go1.12.5 darwin-amd64) jb@kvin.kastelo.net 2019-05-23 16:08:14 UTC [foo, bar]
+// or, somewhere along the way the "+" in the version tag disappeared:
+// syncthing v1.23.7-dev.26.gdf7b56ae.dirty-stversionextra "Fermium Flea" (go1.20.5 darwin-arm64) jb@ok.kastelo.net 2023-07-12 06:55:26 UTC [Some Wrapper, purego, stnoupgrade]
+var (
+	longVersionRE = regexp.MustCompile(`syncthing\s+(v[^\s]+)\s+"([^"]+)"\s\(([^\s]+)\s+([^-]+)-([^)]+)\)\s+([^\s]+)[^\[]*(?:\[(.+)\])?$`)
+	gitExtraRE    = regexp.MustCompile(`\.\d+\.g[0-9a-f]+`) // ".1.g6aaae618"
+	gitExtraSepRE = regexp.MustCompile(`[.-]`)              // dot or dash
+)
+
+type VersionParts struct {
+	Version  string   // "v1.1.4-rc.1+30-g6aaae618-dirty-crashrep"
+	Tag      string   // "v1.1.4-rc.1"
+	Commit   string   // "6aaae618", blank when absent
+	Codename string   // "Erbium Earthworm"
+	Runtime  string   // "go1.12.5"
+	GOOS     string   // "darwin"
+	GOARCH   string   // "amd64"
+	Builder  string   // "jb@kvin.kastelo.net"
+	Extra    []string // "foo", "bar"
+}
+
+func (v VersionParts) Environment() string {
+	if v.Commit != "" {
+		return "Development"
+	}
+	if strings.Contains(v.Tag, "-rc.") {
+		return "Candidate"
+	}
+	if strings.Contains(v.Tag, "-") {
+		return "Beta"
+	}
+	return "Stable"
+}
+
+func ParseVersion(line string) (VersionParts, error) {
+	m := longVersionRE.FindStringSubmatch(line)
+	if len(m) == 0 {
+		return VersionParts{}, errors.New("unintelligeble version string")
+	}
+
+	v := VersionParts{
+		Version:  m[1],
+		Codename: m[2],
+		Runtime:  m[3],
+		GOOS:     m[4],
+		GOARCH:   m[5],
+		Builder:  m[6],
+	}
+
+	// Split the version tag into tag and commit. This is old style
+	// v1.2.3-something.4+11-g12345678 or newer with just dots
+	// v1.2.3-something.4.11.g12345678 or v1.2.3-dev.11.g12345678.
+	parts := []string{v.Version}
+	if strings.Contains(v.Version, "+") {
+		parts = strings.Split(v.Version, "+")
+	} else {
+		idxs := gitExtraRE.FindStringIndex(v.Version)
+		if len(idxs) > 0 {
+			parts = []string{v.Version[:idxs[0]], v.Version[idxs[0]+1:]}
+		}
+	}
+	v.Tag = parts[0]
+	if len(parts) > 1 {
+		fields := gitExtraSepRE.Split(parts[1], -1)
+		if len(fields) >= 2 && strings.HasPrefix(fields[1], "g") {
+			v.Commit = fields[1][1:]
+		}
+	}
+
+	if len(m) >= 8 && m[7] != "" {
+		tags := strings.Split(m[7], ",")
+		for i := range tags {
+			tags[i] = strings.TrimSpace(tags[i])
+		}
+		v.Extra = tags
+	}
+
+	return v, nil
+}
--- a/lib/build/parse_test.go
+++ b/lib/build/parse_test.go
@ -0,0 +1,72 @@
+// Copyright (C) 2019 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 build
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestParseVersion(t *testing.T) {
+	cases := []struct {
+		longVersion string
+		parsed      VersionParts
+	}{
+		{
+			longVersion: `syncthing v1.1.4-rc.1+30-g6aaae618-dirty-crashrep "Erbium Earthworm" (go1.12.5 darwin-amd64) jb@kvin.kastelo.net 2019-05-23 16:08:14 UTC`,
+			parsed: VersionParts{
+				Version:  "v1.1.4-rc.1+30-g6aaae618-dirty-crashrep",
+				Tag:      "v1.1.4-rc.1",
+				Commit:   "6aaae618",
+				Codename: "Erbium Earthworm",
+				Runtime:  "go1.12.5",
+				GOOS:     "darwin",
+				GOARCH:   "amd64",
+				Builder:  "jb@kvin.kastelo.net",
+			},
+		},
+		{
+			longVersion: `syncthing v1.1.4-rc.1+30-g6aaae618-dirty-crashrep "Erbium Earthworm" (go1.12.5 darwin-amd64) jb@kvin.kastelo.net 2019-05-23 16:08:14 UTC [foo, bar]`,
+			parsed: VersionParts{
+				Version:  "v1.1.4-rc.1+30-g6aaae618-dirty-crashrep",
+				Tag:      "v1.1.4-rc.1",
+				Commit:   "6aaae618",
+				Codename: "Erbium Earthworm",
+				Runtime:  "go1.12.5",
+				GOOS:     "darwin",
+				GOARCH:   "amd64",
+				Builder:  "jb@kvin.kastelo.net",
+				Extra:    []string{"foo", "bar"},
+			},
+		},
+		{
+			longVersion: `syncthing v1.23.7-dev.26.gdf7b56ae-stversionextra "Fermium Flea" (go1.20.5 darwin-arm64) jb@ok.kastelo.net 2023-07-12 06:55:26 UTC [Some Wrapper, purego, stnoupgrade]`,
+			parsed: VersionParts{
+				Version:  "v1.23.7-dev.26.gdf7b56ae-stversionextra",
+				Tag:      "v1.23.7-dev",
+				Commit:   "df7b56ae",
+				Codename: "Fermium Flea",
+				Runtime:  "go1.20.5",
+				GOOS:     "darwin",
+				GOARCH:   "arm64",
+				Builder:  "jb@ok.kastelo.net",
+				Extra:    []string{"Some Wrapper", "purego", "stnoupgrade"},
+			},
+		},
+	}
+
+	for _, tc := range cases {
+		v, err := ParseVersion(tc.longVersion)
+		if err != nil {
+			t.Errorf("%s\nerror: %v\n", tc.longVersion, err)
+			continue
+		}
+		if fmt.Sprint(v) != fmt.Sprint(tc.parsed) {
+			t.Errorf("%s\nA: %v\nE: %v\n", tc.longVersion, v, tc.parsed)
+		}
+	}
+}