feat: Настройки › Автообновление - clients compare their version with the server's every N and update themselves; the server looks at GitLab every N and, when a newer release is out, offers it to an administrator at login (after the PIN) with «Обновить» and «Отказаться»; the words of a made picture's result are the model's only

README.md

@@ -67,6 +67,13 @@
   не расшифровать.
 - **Проброс портов** - `http` через панель, `tcp`/`udp` через прямой туннель.
 - **Статус** - нагрузка, память, диски, сеть, тест скорости канала до сервера.
+- **Автообновление** («Настройки › Автообновление», обе части выключены, пока не включены):
+  *клиентов* - агенты раз в N минут/часов/суток сверяют свою версию с версией сервера и, если у сервера новее,
+  обновляются сами (как по кнопке «Обновить»; нужен root или sudo без пароля; агентам до 0.2.5 один раз обновиться
+  придётся вручную); *сервера* - сервер раз в N сверяет себя с последним релизом на GitLab, и когда вышел новый,
+  администратору при входе (после PIN) показывается окно «Обновить / Отказаться» - отказ запоминается для этой
+  версии. «Обновить» запускает `server-install.sh` отдельной службой systemd (нужны root и systemd); там же кнопки
+  «Проверить сейчас» и «Обновить сейчас».
 - **Вход** - пароль и/или ключи доступа (passkeys); пароль можно выключить, когда есть ключ.
 - **PIN-код** (необязательный, 4 цифры) - спрашивается в каждой новой вкладке браузера, но не при
   перезагрузке. На устройстве можно не спрашивать его 5/15/30/60 минут после ввода.

cmd/server/main.go

@@ -6,6 +6,7 @@
 package main
 
 import (
+	"context"
 	"flag"
 	"log"
 	"net/http"
@@ -42,6 +43,9 @@ func main() {
 		log.Fatalf("init server: %v", err)
 	}
 
+	// The server updates itself, if told to (Настройки › Автообновление).
+	go srv.RunAutoUpdate(context.Background())
+
 	httpSrv := &http.Server{
 		Addr:    *addr,
 		Handler: srv.Handler(),

internal/agent/autoupdate.go

@@ -0,0 +1,95 @@
+package agent
+
+import (
+	"context"
+	"log"
+	"net/http"
+	"strconv"
+	"sync"
+	"time"
+
+	"github.com/x-grk/longpolling-remote-access/internal/proto"
+)
+
+// Auto-update, the agent's part: the server tells (with every poll, on its
+// config and on the WebSocket) its own version and how often to compare -
+// in minutes, 0 for never. When the server's version is newer, the agent
+// takes the new one from it, as the panel's «Обновить» does.
+
+// autoUpdate is what the agent was told, and when it last looked.
+type autoUpdate struct {
+	mu        sync.Mutex
+	minutes   int
+	serverVer string
+	last      time.Time
+}
+
+func (a *Agent) applyUpdateInfo(minutes int, serverVersion string) {
+	a.auto.mu.Lock()
+	defer a.auto.mu.Unlock()
+	if minutes < 0 {
+		minutes = 0
+	}
+	a.auto.minutes = minutes
+	if serverVersion != "" {
+		a.auto.serverVer = serverVersion
+	}
+}
+
+// applyUpdateHeaders takes the settings from the headers of an answer; an
+// answer without them (an older server) changes nothing.
+func (a *Agent) applyUpdateHeaders(h http.Header) {
+	v := h.Get(proto.AutoUpdateHeader)
+	if v == "" {
+		return
+	}
+	m, err := strconv.Atoi(v)
+	if err != nil {
+		m = 0
+	}
+	a.applyUpdateInfo(m, h.Get(proto.ServerVersionHeader))
+}
+
+func (a *Agent) updateInfo() (int, string) {
+	a.auto.mu.Lock()
+	defer a.auto.mu.Unlock()
+	return a.auto.minutes, a.auto.serverVer
+}
+
+func (a *Agent) autoUpdateOn() bool { m, _ := a.updateInfo(); return m > 0 }
+
+// autoUpdateTick: one look at the clock. Out of the interval since the last
+// look, it looks; the server's version newer than its own, it updates.
+// Reports whether it did.
+func (a *Agent) autoUpdateTick(now time.Time, update func() proto.TaskResult) bool {
+	a.auto.mu.Lock()
+	if a.auto.minutes <= 0 || (!a.auto.last.IsZero() && now.Sub(a.auto.last) < time.Duration(a.auto.minutes)*time.Minute) {
+		a.auto.mu.Unlock()
+		return false
+	}
+	a.auto.last = now
+	server := a.auto.serverVer
+	a.auto.mu.Unlock()
+	if !proto.VersionNewer(server, Version) {
+		return false
+	}
+	log.Printf("auto-update: server has %s, this is %s - updating", server, Version)
+	if res := update(); !res.OK {
+		log.Printf("auto-update: %s", res.Error)
+	}
+	return true
+}
+
+// autoUpdateLoop watches the clock until ctx ends.
+func (a *Agent) autoUpdateLoop(ctx context.Context) {
+	t := time.NewTicker(30 * time.Second)
+	defer t.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case now := <-t.C:
+			a.autoUpdateTick(now, a.doUpdate)
+		}
+	}
+}

internal/agent/autoupdate_test.go

@@ -0,0 +1,78 @@
+package agent
+
+import (
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/x-grk/longpolling-remote-access/internal/proto"
+)
+
+// updates counts what an agent was made to update with.
+type updates struct{ n int }
+
+func (u *updates) do() proto.TaskResult { u.n++; return proto.TaskResult{OK: true} }
+
+// The agent is told, by headers or by the WebSocket's message, how often to
+// compare versions; nothing told, nothing done.
+func TestAutoUpdateIsTold(t *testing.T) {
+	a := New(Config{})
+	if a.autoUpdateOn() {
+		t.Fatal("on with nothing told")
+	}
+	h := http.Header{}
+	h.Set(proto.AutoUpdateHeader, "90")
+	h.Set(proto.ServerVersionHeader, "9.9.9")
+	a.applyUpdateHeaders(h)
+	if m, v := a.updateInfo(); m != 90 || v != "9.9.9" {
+		t.Fatalf("by headers: %d %q", m, v)
+	}
+	a.applyUpdateInfo(0, "9.9.9")
+	if a.autoUpdateOn() {
+		t.Fatal("still on after being told 0")
+	}
+	a.applyUpdateInfo(30, "9.9.9")
+	if m, _ := a.updateInfo(); m != 30 {
+		t.Fatalf("by the message: %d", m)
+	}
+	// Rubbish is not taken for a number.
+	h.Set(proto.AutoUpdateHeader, "soon")
+	a.applyUpdateHeaders(h)
+	if m, _ := a.updateInfo(); m != 0 {
+		t.Fatalf("rubbish: %d", m)
+	}
+}
+
+// When the interval is out the agent looks; it updates only to a newer
+// version of the server's, and tries again the next time if it did not work.
+func TestAutoUpdateTick(t *testing.T) {
+	a := New(Config{})
+	u := &updates{}
+	now := time.Now()
+	a.applyUpdateInfo(60, "9.9.9")
+
+	if !a.autoUpdateTick(now, u.do) || u.n != 1 {
+		t.Fatalf("a newer server: %d updates", u.n)
+	}
+	if a.autoUpdateTick(now.Add(30*time.Minute), u.do) || u.n != 1 {
+		t.Fatalf("before the interval is out: %d updates", u.n)
+	}
+	if !a.autoUpdateTick(now.Add(61*time.Minute), u.do) || u.n != 2 {
+		t.Fatalf("at the next time: %d updates", u.n)
+	}
+
+	// The same, an older one, a build that is not a version: nothing.
+	for _, v := range []string{Version, "0.0.1", "dev", ""} {
+		b := New(Config{})
+		b.applyUpdateInfo(60, v)
+		if b.autoUpdateTick(now, u.do) {
+			t.Fatalf("updated to %q", v)
+		}
+	}
+	// Off: nothing, whatever the server has.
+	c := New(Config{})
+	c.applyUpdateInfo(0, "9.9.9")
+	if c.autoUpdateTick(now, u.do) || u.n != 2 {
+		t.Fatalf("off, yet updated: %d", u.n)
+	}
+}

internal/agent/client.go

@@ -64,6 +64,8 @@ type Agent struct {
 	tunMu     sync.Mutex
 	tunAddr   string
 	tunCancel context.CancelFunc
+
+	auto autoUpdate // what the server told of auto-update
 }
 
 // New builds an agent. It does not perform any network I/O.
@@ -115,6 +117,7 @@ func (a *Agent) Run(ctx context.Context) error {
 		}
 	}
 	go a.watchMain(ctx)
+	go a.autoUpdateLoop(ctx)
 	log.Printf("agent %s connected to %s", a.state.AgentID, a.host())
 
 	// Direct forward tunnel (low-latency TCP mux + UDP). Its address comes
@@ -321,6 +324,7 @@ func (a *Agent) pollOnce(ctx, reqCtx context.Context) error {
 	a.applyTunnelHeader(ctx, resp.Header)
 	a.learnAddrs(resp.Header.Get(proto.MainHeader), resp.Header.Get(proto.FallbackHeader))
 	a.applyTransport(resp.Header.Get(proto.TransportHeader))
+	a.applyUpdateHeaders(resp.Header)
 	a.dispatch(ctx, msg)
 	return nil
 }
@@ -356,6 +360,7 @@ func (a *Agent) fetchConfig(ctx context.Context) bool {
 	defer resp.Body.Close()
 	a.applyTransport(resp.Header.Get(proto.TransportHeader))
 	a.learnAddrs(resp.Header.Get(proto.MainHeader), resp.Header.Get(proto.FallbackHeader))
+	a.applyUpdateHeaders(resp.Header)
 	return a.applyTunnelHeader(ctx, resp.Header)
 }
 

internal/agent/wslink.go

@@ -167,6 +167,7 @@ func (a *Agent) runWS(ctx context.Context) error {
 			a.applyTunnelAddr(ctx, m.Tunnel)
 			a.learnAddrs(m.Main, m.Fallback)
 			a.applyTransport(m.Transport)
+			a.applyUpdateInfo(m.AutoUpdate, m.ServerVersion)
 			if a.mode() == proto.TransportLP {
 				return errors.New("set to long polling")
 			}

internal/proto/proto.go

@@ -103,8 +103,19 @@ type WSMsg struct {
 	Transport string          `json:"transport,omitempty"`
 	Fallback  string          `json:"fallback,omitempty"`
 	Main      string          `json:"main,omitempty"`
+	// Auto-update of agents: how often (minutes) an agent compares its
+	// version with the server's and updates itself if the server's is newer;
+	// 0 or missing - it does not. ServerVersion is the server's.
+	AutoUpdate    int    `json:"autoupdate,omitempty"`
+	ServerVersion string `json:"server_version,omitempty"`
 }
 
+// Headers with the same on the poll answer and on /api/agent/config.
+const (
+	AutoUpdateHeader    = "X-Auto-Update"    // minutes, "0" or missing: off
+	ServerVersionHeader = "X-Server-Version" // the server's release version
+)
+
 // Terminal / stream frame types on the session "in" channel (server -> agent).
 // Reused for both PTY terminals and raw TCP port-forward streams.
 const (

internal/proto/version.go

@@ -0,0 +1,50 @@
+package proto
+
+import (
+	"strconv"
+	"strings"
+)
+
+// versionParts reads "0.2.5" (a leading v and a "-suffix" are allowed) as
+// numbers; ok is false for anything that is not a dotted number.
+func versionParts(v string) (parts []int, ok bool) {
+	v = strings.TrimPrefix(strings.TrimSpace(v), "v")
+	if i := strings.IndexAny(v, "-+"); i >= 0 {
+		v = v[:i]
+	}
+	if v == "" {
+		return nil, false
+	}
+	for _, p := range strings.Split(v, ".") {
+		n, err := strconv.Atoi(p)
+		if err != nil || n < 0 {
+			return nil, false
+		}
+		parts = append(parts, n)
+	}
+	return parts, true
+}
+
+// VersionNewer reports whether version a is higher than b. Anything that is
+// not a dotted number (a build named "dev", an empty string) is never newer
+// and never older - so a program is never "updated" down, or from a guess.
+func VersionNewer(a, b string) bool {
+	pa, okA := versionParts(a)
+	pb, okB := versionParts(b)
+	if !okA || !okB {
+		return false
+	}
+	for i := 0; i < len(pa) || i < len(pb); i++ {
+		var x, y int
+		if i < len(pa) {
+			x = pa[i]
+		}
+		if i < len(pb) {
+			y = pb[i]
+		}
+		if x != y {
+			return x > y
+		}
+	}
+	return false
+}

internal/proto/version_test.go

@@ -0,0 +1,30 @@
+package proto
+
+import "testing"
+
+// A version is newer only when it is a higher dotted number: never for the
+// same, an older one, or what is not a version at all.
+func TestVersionNewer(t *testing.T) {
+	for _, c := range []struct {
+		a, b string
+		want bool
+	}{
+		{"0.2.5", "0.2.4", true},
+		{"0.2.10", "0.2.9", true},
+		{"0.3.0", "0.2.99", true},
+		{"1.0", "0.9.9", true},
+		{"0.2.4", "0.2.4", false},
+		{"0.2.3", "0.2.4", false},
+		{"0.2", "0.2.0", false},
+		{"v0.2.5", "0.2.4", true},
+		{"", "0.2.4", false},
+		{"dev", "0.2.4", false},
+		{"0.2.5", "dev", false},
+		{"0.2.5", "", false},
+		{"0.2.5-rc1", "0.2.4", true},
+	} {
+		if got := VersionNewer(c.a, c.b); got != c.want {
+			t.Errorf("VersionNewer(%q, %q) = %v, want %v", c.a, c.b, got, c.want)
+		}
+	}
+}

internal/server/autoupdate.go

@@ -0,0 +1,389 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/x-grk/longpolling-remote-access/internal/proto"
+)
+
+// Auto-update, two kinds, each off until asked for (Настройки › Автообновление):
+//   - of the agents: they are told how often to compare their version with
+//     the server's and, if the server's is newer, to take the agent from it
+//     (as the panel's «Обновить» does);
+//   - of the server: it compares itself with the latest release on GitLab;
+//     when that is newer, an administrator is offered it at login (after the
+//     PIN), and on «Обновить» the install script is run (the same one as
+//     `wget -qO- …/server-install.sh | sudo sh`). Nothing runs unasked.
+
+const (
+	cfgAgentAuto     = "agent_autoupdate"
+	cfgAgentAutoMin  = "agent_autoupdate_min"
+	cfgServerAuto    = "server_autoupdate"
+	cfgServerAutoMin = "server_autoupdate_min"
+
+	// Where releases are. Not in the settings: for tests.
+	cfgUpdateRepo = "update_repo"
+	cfgUpdateBase = "update_base"
+
+	DefaultUpdateRepo = "itzredtea/lpra"
+	DefaultUpdateBase = "https://gitlab.com"
+
+	defaultAutoMin = 360          // 6 hours
+	maxAutoMin     = 60 * 24 * 30 // 30 days
+)
+
+// autoSetting reads an "on" flag and its interval in minutes.
+func (s *Server) autoSetting(onKey, minKey string) (bool, int) {
+	on, _ := s.db.GetConfig(onKey)
+	m, _ := strconv.Atoi(func() string { v, _ := s.db.GetConfig(minKey); return v }())
+	if m < 1 || m > maxAutoMin {
+		m = defaultAutoMin
+	}
+	return on == "1", m
+}
+
+func (s *Server) agentAuto() (bool, int)  { return s.autoSetting(cfgAgentAuto, cfgAgentAutoMin) }
+func (s *Server) serverAuto() (bool, int) { return s.autoSetting(cfgServerAuto, cfgServerAutoMin) }
+
+// setUpdateHeaders tells an agent the server's version and how often to
+// compare ("0": never).
+func (s *Server) setUpdateHeaders(w http.ResponseWriter) {
+	w.Header().Set(proto.ServerVersionHeader, Version)
+	w.Header().Set(proto.AutoUpdateHeader, strconv.Itoa(s.agentAutoMinutes()))
+}
+
+// agentAutoMinutes is the interval agents are given, 0 when off.
+func (s *Server) agentAutoMinutes() int {
+	if on, m := s.agentAuto(); on {
+		return m
+	}
+	return 0
+}
+
+// minutesOf turns "2" and "h" into 120: min, h, d.
+func minutesOf(n, unit string) int {
+	v, err := strconv.Atoi(strings.TrimSpace(n))
+	if err != nil || v < 1 {
+		return defaultAutoMin
+	}
+	switch unit {
+	case "h":
+		v *= 60
+	case "d":
+		v *= 60 * 24
+	}
+	if v > maxAutoMin {
+		v = maxAutoMin
+	}
+	return v
+}
+
+// POST /settings/autoupdate - both settings.
+func (s *Server) handleSetAutoUpdate(w http.ResponseWriter, r *http.Request) {
+	if !checkCSRF(r) {
+		http.Error(w, "bad csrf", http.StatusForbidden)
+		return
+	}
+	flag := func(v string) string {
+		if v == "1" {
+			return "1"
+		}
+		return ""
+	}
+	_ = s.db.SetConfig(cfgAgentAuto, flag(r.FormValue("agent_auto")))
+	_ = s.db.SetConfig(cfgAgentAutoMin, strconv.Itoa(minutesOf(r.FormValue("agent_every"), r.FormValue("agent_unit"))))
+	_ = s.db.SetConfig(cfgServerAuto, flag(r.FormValue("server_auto")))
+	_ = s.db.SetConfig(cfgServerAutoMin, strconv.Itoa(minutesOf(r.FormValue("server_every"), r.FormValue("server_unit"))))
+	// A server that was told to look again looks at once.
+	s.upd.mu.Lock()
+	s.upd.last = time.Time{}
+	s.upd.mu.Unlock()
+	http.Redirect(w, r, "/settings#autoupdate", http.StatusSeeOther)
+}
+
+// intervalParts is a number of minutes as the form shows it: 120 - 2 h.
+func intervalParts(min int) (int, string) {
+	switch {
+	case min%(60*24) == 0:
+		return min / (60 * 24), "d"
+	case min%60 == 0:
+		return min / 60, "h"
+	}
+	return min, "min"
+}
+
+// autoView is what Настройки show of the settings.
+type autoView struct {
+	AgentOn, ServerOn       bool
+	AgentEvery, ServerEvery int
+	AgentUnit, ServerUnit   string
+	Status                  updStatus
+}
+
+func (s *Server) autoView() autoView {
+	var v autoView
+	var am, sm int
+	v.AgentOn, am = s.agentAuto()
+	v.ServerOn, sm = s.serverAuto()
+	v.AgentEvery, v.AgentUnit = intervalParts(am)
+	v.ServerEvery, v.ServerUnit = intervalParts(sm)
+	v.Status = s.updateStatus()
+	return v
+}
+
+// updState is what the updating of the server remembers.
+type updState struct {
+	mu      sync.Mutex
+	last    time.Time // when it last looked
+	latest  string
+	checked time.Time
+	err     string
+}
+
+// updStatus is that, for the settings page.
+type updStatus struct {
+	Current, Latest string
+	Checked         string
+	Error           string
+	Newer           bool
+}
+
+func (s *Server) updateStatus() updStatus {
+	s.upd.mu.Lock()
+	defer s.upd.mu.Unlock()
+	st := updStatus{Current: Version, Latest: s.upd.latest, Error: s.upd.err, Newer: proto.VersionNewer(s.upd.latest, Version)}
+	if !s.upd.checked.IsZero() {
+		st.Checked = s.upd.checked.Format("02.01.2006 15:04")
+	}
+	return st
+}
+
+func (s *Server) updateRepoBase() (base, repo string) {
+	base, _ = s.db.GetConfig(cfgUpdateBase)
+	if base == "" {
+		base = DefaultUpdateBase
+	}
+	repo, _ = s.db.GetConfig(cfgUpdateRepo)
+	if repo == "" {
+		repo = DefaultUpdateRepo
+	}
+	return strings.TrimRight(base, "/"), repo
+}
+
+var updateClient = &http.Client{Timeout: 30 * time.Second}
+
+// latestRelease is the tag of the project's latest release on GitLab.
+func (s *Server) latestRelease(ctx context.Context) (string, error) {
+	base, repo := s.updateRepoBase()
+	req, _ := http.NewRequestWithContext(ctx, http.MethodGet, base+"/api/v4/projects/"+url.PathEscape(repo)+"/releases/permalink/latest", nil)
+	req.Header.Set("Accept", "application/json")
+	resp, err := updateClient.Do(req)
+	if err != nil {
+		return "", errors.New("GitLab не отвечает: " + err.Error())
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode/100 != 2 {
+		return "", errors.New("GitLab ответил " + resp.Status)
+	}
+	var out struct {
+		Tag string `json:"tag_name"`
+	}
+	if err := json.NewDecoder(io.LimitReader(resp.Body, 1<<20)).Decode(&out); err != nil || out.Tag == "" {
+		return "", errors.New("не прочиталась версия последнего релиза")
+	}
+	return strings.TrimPrefix(out.Tag, "v"), nil
+}
+
+// checkRelease looks at GitLab and keeps what it found for the page.
+func (s *Server) checkRelease(ctx context.Context) (string, error) {
+	tag, err := s.latestRelease(ctx)
+	s.upd.mu.Lock()
+	defer s.upd.mu.Unlock()
+	s.upd.checked = time.Now()
+	if err != nil {
+		s.upd.err = err.Error()
+		return "", err
+	}
+	s.upd.latest, s.upd.err = tag, ""
+	return tag, nil
+}
+
+// installScript is the install script on the project's main branch.
+func (s *Server) installScript(ctx context.Context) ([]byte, error) {
+	base, repo := s.updateRepoBase()
+	req, _ := http.NewRequestWithContext(ctx, http.MethodGet, base+"/"+repo+"/-/raw/main/server-install.sh", nil)
+	resp, err := updateClient.Do(req)
+	if err != nil {
+		return nil, errors.New("скрипт установки не скачался: " + err.Error())
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode/100 != 2 {
+		return nil, errors.New("скрипт установки: GitLab ответил " + resp.Status)
+	}
+	b, _ := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	// What is run as root must be the script, not a page of an error.
+	if !strings.HasPrefix(string(b), "#!/bin/sh\n") || !strings.Contains(string(b), "LPRA server") {
+		return nil, errors.New("по адресу скрипта установки лежит не он")
+	}
+	return b, nil
+}
+
+// startServerUpdate takes the install script and has it run, apart from
+// this process: it stops the service, and a script in the service's own
+// control group would go with it.
+func (s *Server) startServerUpdate(ctx context.Context) error {
+	script, err := s.installScript(ctx)
+	if err != nil {
+		return err
+	}
+	run := s.updRun
+	if run == nil {
+		run = runServerUpdate
+	}
+	return run(script)
+}
+
+// runServerUpdate runs the script as a transient systemd unit of its own,
+// in the folder this server lives in. Needs root and systemd.
+func runServerUpdate(script []byte) error {
+	if os.Geteuid() != 0 {
+		return errors.New("сервер запущен не от root - обновить его самому нельзя, запустите server-install.sh")
+	}
+	sr, err := exec.LookPath("systemd-run")
+	if err != nil {
+		return errors.New("нет systemd-run - автообновление сервера работает только под systemd")
+	}
+	exe, err := os.Executable()
+	if err != nil {
+		return err
+	}
+	dir := filepath.Dir(exe)
+	path := filepath.Join(dir, ".server-update.sh")
+	if err := os.WriteFile(path, script, 0o700); err != nil {
+		return errors.New("скрипт не записался: " + err.Error())
+	}
+	out, err := exec.Command(sr, "--unit=lpra-self-update", "--collect", "--setenv=LPRA_DIR="+dir,
+		"/bin/sh", "-c", "sh '"+path+"'; rm -f '"+path+"'").CombinedOutput()
+	if err != nil {
+		_ = os.Remove(path)
+		return fmt.Errorf("systemd-run: %s", strings.TrimSpace(string(out)))
+	}
+	return nil
+}
+
+// autoUpdateTick: one look at the clock. When the server is to look at
+// GitLab (on, and the interval is out) it does, and keeps what it found.
+func (s *Server) autoUpdateTick(now time.Time) {
+	on, min := s.serverAuto()
+	if !on {
+		return
+	}
+	s.upd.mu.Lock()
+	if !s.upd.last.IsZero() && now.Sub(s.upd.last) < time.Duration(min)*time.Minute {
+		s.upd.mu.Unlock()
+		return
+	}
+	s.upd.last = now
+	s.upd.mu.Unlock()
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+	_, _ = s.checkRelease(ctx)
+}
+
+// RunAutoUpdate watches the clock until ctx ends.
+func (s *Server) RunAutoUpdate(ctx context.Context) {
+	t := time.NewTicker(30 * time.Second)
+	defer t.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case now := <-t.C:
+			s.autoUpdateTick(now)
+		}
+	}
+}
+
+// POST /api/panel/update/check - looks at GitLab now.
+func (s *Server) handleUpdateCheck(w http.ResponseWriter, r *http.Request) {
+	tag, err := s.checkRelease(r.Context())
+	if err != nil {
+		writeJSON(w, map[string]any{"ok": false, "error": err.Error(), "current": Version})
+		return
+	}
+	writeJSON(w, map[string]any{"ok": true, "current": Version, "latest": tag, "newer": proto.VersionNewer(tag, Version)})
+}
+
+// POST /api/panel/update/run - updates the server now, to a newer release.
+func (s *Server) handleUpdateRun(w http.ResponseWriter, r *http.Request) {
+	tag, err := s.checkRelease(r.Context())
+	if err != nil {
+		writeJSON(w, map[string]any{"ok": false, "error": err.Error()})
+		return
+	}
+	if !proto.VersionNewer(tag, Version) {
+		writeJSON(w, map[string]any{"ok": false, "error": "уже последняя версия (" + Version + ")"})
+		return
+	}
+	if err := s.startServerUpdate(r.Context()); err != nil {
+		writeJSON(w, map[string]any{"ok": false, "error": err.Error()})
+		return
+	}
+	writeJSON(w, map[string]any{"ok": true, "latest": tag})
+}
+
+func declinedKey(id int64) string { return "update_declined_" + strconv.FormatInt(id, 10) }
+
+// GET /api/panel/update/offer - whether this administrator is to be offered
+// an update now: auto-update on, a release newer than this one, and not one
+// they declined.
+func (s *Server) handleUpdateOffer(w http.ResponseWriter, r *http.Request) {
+	no := func() { writeJSON(w, map[string]any{"offer": false}) }
+	on, min := s.serverAuto()
+	if !on {
+		no()
+		return
+	}
+	// Not looked at lately (just started, or the interval is out): look now.
+	s.upd.mu.Lock()
+	stale := s.upd.checked.IsZero() || time.Since(s.upd.checked) >= time.Duration(min)*time.Minute
+	s.upd.mu.Unlock()
+	if stale {
+		ctx, cancel := context.WithTimeout(r.Context(), 10*time.Second)
+		_, _ = s.checkRelease(ctx)
+		cancel()
+	}
+	st := s.updateStatus()
+	declined, _ := s.db.GetConfig(declinedKey(s.currentAdmin(r).ID))
+	if !st.Newer || declined == st.Latest {
+		no()
+		return
+	}
+	writeJSON(w, map[string]any{"offer": true, "current": st.Current, "latest": st.Latest})
+}
+
+// POST /api/panel/update/decline - {version}: this administrator is not to
+// be asked about that release again.
+func (s *Server) handleUpdateDecline(w http.ResponseWriter, r *http.Request) {
+	var in struct {
+		Version string `json:"version"`
+	}
+	if json.NewDecoder(http.MaxBytesReader(w, r.Body, 1<<10)).Decode(&in) == nil && len(in.Version) <= 32 {
+		_ = s.db.SetConfig(declinedKey(s.currentAdmin(r).ID), in.Version)
+	}
+	writeJSON(w, map[string]any{"ok": true})
+}

internal/server/autoupdate_test.go

@@ -0,0 +1,272 @@
+package server
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/x-grk/longpolling-remote-access/internal/proto"
+)
+
+// fakeGitLab is the place releases come from: the latest release's tag and
+// the install script on main.
+type fakeGitLab struct {
+	srv    *httptest.Server
+	mu     sync.Mutex
+	tag    string
+	script string
+	hits   int
+}
+
+func newFakeGitLab(t *testing.T, tag string) *fakeGitLab {
+	g := &fakeGitLab{tag: tag, script: "#!/bin/sh\n# LPRA server: install or update in one command.\necho updating\n"}
+	g.srv = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		g.mu.Lock()
+		defer g.mu.Unlock()
+		g.hits++
+		switch r.URL.EscapedPath() {
+		case "/api/v4/projects/itzredtea%2Flpra/releases/permalink/latest":
+			// The real one sends the caller on to the release itself.
+			http.Redirect(w, r, "/api/v4/projects/1/releases/"+g.tag, http.StatusFound)
+		case "/api/v4/projects/1/releases/" + g.tag:
+			fmt.Fprintf(w, `{"tag_name":%q}`, g.tag)
+		case "/itzredtea/lpra/-/raw/main/server-install.sh":
+			fmt.Fprint(w, g.script)
+		default:
+			http.NotFound(w, r)
+		}
+	}))
+	t.Cleanup(g.srv.Close)
+	return g
+}
+
+func useFakeGitLab(s *Server, g *fakeGitLab) {
+	_ = s.db.SetConfig(cfgUpdateBase, g.srv.URL)
+}
+
+// A runner that only notes what it was given, in place of a real update.
+type runs struct {
+	mu      sync.Mutex
+	scripts []string
+	err     error
+}
+
+func (r *runs) run(script []byte) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	r.scripts = append(r.scripts, string(script))
+	return r.err
+}
+
+func (r *runs) n() int { r.mu.Lock(); defer r.mu.Unlock(); return len(r.scripts) }
+
+// postAuto sends the form of Настройки › Автообновление.
+func postAuto(t *testing.T, s *Server, c *http.Cookie, f url.Values) {
+	t.Helper()
+	f.Set("csrf", "tok")
+	req := httptest.NewRequest(http.MethodPost, "/settings/autoupdate", strings.NewReader(f.Encode()))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.AddCookie(c)
+	req.AddCookie(&http.Cookie{Name: csrfCookie, Value: "tok"})
+	w := httptest.NewRecorder()
+	s.Handler().ServeHTTP(w, req)
+	if w.Code != http.StatusSeeOther {
+		t.Fatalf("save: %d %s", w.Code, w.Body)
+	}
+}
+
+// The settings are kept in minutes whatever unit they were given in, and
+// off unless asked for.
+func TestAutoUpdateSettings(t *testing.T) {
+	s, c := newTestServer(t)
+	if on, _ := s.agentAuto(); on {
+		t.Fatal("agents update by themselves with nothing set")
+	}
+	postAuto(t, s, c, url.Values{"agent_auto": {"1"}, "agent_every": {"2"}, "agent_unit": {"h"}, "server_auto": {"1"}, "server_every": {"1"}, "server_unit": {"d"}})
+	if on, m := s.agentAuto(); !on || m != 120 {
+		t.Fatalf("agents: %v %d", on, m)
+	}
+	if on, m := s.serverAuto(); !on || m != 1440 {
+		t.Fatalf("server: %v %d", on, m)
+	}
+	// Out of range or not a number: the default, or the largest.
+	postAuto(t, s, c, url.Values{"agent_auto": {"1"}, "agent_every": {"x"}, "agent_unit": {"min"}, "server_every": {"999"}, "server_unit": {"d"}})
+	if _, m := s.agentAuto(); m != defaultAutoMin {
+		t.Fatalf("a bad number: %d", m)
+	}
+	if on, m := s.serverAuto(); on || m != maxAutoMin {
+		t.Fatalf("server off, a large number: %v %d", on, m)
+	}
+	body := get(t, s, c, "/settings?frag=1").Body.String()
+	if !strings.Contains(body, `id="autoupdate"`) || !strings.Contains(body, "Автообновление клиентов") || !strings.Contains(body, "Автообновление сервера") {
+		t.Fatal("the settings page has no auto-update card")
+	}
+}
+
+// Agents are told of it - on the config they fetch, and with their poll -
+// together with the server's own version.
+func TestAgentsToldOfAutoUpdate(t *testing.T) {
+	s, c := newTestServer(t)
+	if err := s.db.CreateAgent(Agent{ID: "a2", Name: "n", Hostname: "h", OS: "linux", Arch: "amd64", TokenHash: hashToken("tok2")}); err != nil {
+		t.Fatal(err)
+	}
+	cfg := func() http.Header {
+		req := httptest.NewRequest(http.MethodGet, "/api/agent/config", nil)
+		req.Header.Set("X-Agent-Id", "a2")
+		req.Header.Set("Authorization", "Bearer tok2")
+		w := httptest.NewRecorder()
+		s.Handler().ServeHTTP(w, req)
+		if w.Code != http.StatusNoContent {
+			t.Fatalf("config: %d", w.Code)
+		}
+		return w.Header()
+	}
+	h := cfg()
+	if h.Get(proto.AutoUpdateHeader) != "0" || h.Get(proto.ServerVersionHeader) != Version {
+		t.Fatalf("off: %v", h)
+	}
+	postAuto(t, s, c, url.Values{"agent_auto": {"1"}, "agent_every": {"90"}, "agent_unit": {"min"}})
+	if h := cfg(); h.Get(proto.AutoUpdateHeader) != "90" {
+		t.Fatalf("on: %v", h)
+	}
+}
+
+// The latest release is read from GitLab, through its redirect.
+func TestLatestRelease(t *testing.T) {
+	s, _ := newTestServer(t)
+	g := newFakeGitLab(t, "9.9.9")
+	useFakeGitLab(s, g)
+	tag, err := s.latestRelease(t.Context())
+	if err != nil || tag != "9.9.9" {
+		t.Fatalf("latest: %q %v", tag, err)
+	}
+	g.srv.Close()
+	if _, err := s.latestRelease(t.Context()); err == nil {
+		t.Fatal("no error with GitLab out of reach")
+	}
+}
+
+// With auto-update on the server looks at GitLab by itself, at the interval,
+// and only looks: updating is the administrator's to say yes to.
+func TestServerAutoUpdateTick(t *testing.T) {
+	s, c := newTestServer(t)
+	g := newFakeGitLab(t, "99.0.0")
+	useFakeGitLab(s, g)
+	r := &runs{}
+	s.updRun = r.run
+	now := time.Now()
+
+	s.autoUpdateTick(now)
+	if g.hits != 0 {
+		t.Fatalf("off, yet it looked: %d hits", g.hits)
+	}
+	postAuto(t, s, c, url.Values{"server_auto": {"1"}, "server_every": {"60"}, "server_unit": {"min"}})
+	s.autoUpdateTick(now)
+	if st := s.updateStatus(); st.Latest != "99.0.0" || !st.Newer {
+		t.Fatalf("it did not learn of the release: %+v", st)
+	}
+	hits := g.hits
+	s.autoUpdateTick(now.Add(10 * time.Minute))
+	if g.hits != hits {
+		t.Fatal("it looked again before the interval was out")
+	}
+	s.autoUpdateTick(now.Add(61 * time.Minute))
+	if g.hits == hits {
+		t.Fatal("it did not look when the interval was out")
+	}
+	if r.n() != 0 {
+		t.Fatalf("it updated by itself: %d runs", r.n())
+	}
+	// GitLab out of reach: told on the page, kept until it answers.
+	g.srv.Close()
+	s.autoUpdateTick(now.Add(130 * time.Minute))
+	if st := s.updateStatus(); st.Error == "" {
+		t.Fatalf("the failure is not kept: %+v", st)
+	}
+}
+
+// What an administrator is offered at login: a newer release, with
+// auto-update on, not one they said no to - and again when a newer one comes.
+func TestUpdateOffer(t *testing.T) {
+	s, c := newTestServer(t)
+	g := newFakeGitLab(t, "99.0.0")
+	useFakeGitLab(s, g)
+	offer := func() string { return apiCall(t, s, c, "GET", "/api/panel/update/offer", "") }
+	if got := offer(); !strings.Contains(got, `"offer":false`) {
+		t.Fatalf("auto-update off: %s", got)
+	}
+	postAuto(t, s, c, url.Values{"server_auto": {"1"}, "server_every": {"60"}, "server_unit": {"min"}})
+	got := offer()
+	if !strings.Contains(got, `"offer":true`) || !strings.Contains(got, `"latest":"99.0.0"`) || !strings.Contains(got, `"current":"`+Version+`"`) {
+		t.Fatalf("a newer release: %s", got)
+	}
+	apiCall(t, s, c, "POST", "/api/panel/update/decline", `{"version":"99.0.0"}`)
+	if got := offer(); !strings.Contains(got, `"offer":false`) {
+		t.Fatalf("after saying no: %s", got)
+	}
+	g.tag = "99.1.0"
+	s.upd.mu.Lock()
+	s.upd.checked = time.Time{}
+	s.upd.mu.Unlock()
+	if got := offer(); !strings.Contains(got, `"offer":true`) || !strings.Contains(got, `"latest":"99.1.0"`) {
+		t.Fatalf("a still newer release: %s", got)
+	}
+	g.tag = Version
+	s.upd.mu.Lock()
+	s.upd.checked = time.Time{}
+	s.upd.mu.Unlock()
+	if got := offer(); !strings.Contains(got, `"offer":false`) {
+		t.Fatalf("nothing newer: %s", got)
+	}
+}
+
+// Anything but the install script is not run: a page of GitLab's, say.
+func TestUpdateScriptChecked(t *testing.T) {
+	s, _ := newTestServer(t)
+	g := newFakeGitLab(t, "99.0.0")
+	g.script = "<html>502 Bad Gateway</html>"
+	useFakeGitLab(s, g)
+	r := &runs{}
+	s.updRun = r.run
+	if err := s.startServerUpdate(t.Context()); err == nil || r.n() != 0 {
+		t.Fatalf("a page was run as a script: %v, %d runs", err, r.n())
+	}
+}
+
+// From the panel: check now, and update now - only to a newer release.
+func TestUpdatePanelButtons(t *testing.T) {
+	s, c := newTestServer(t)
+	g := newFakeGitLab(t, "99.0.0")
+	useFakeGitLab(s, g)
+	r := &runs{}
+	s.updRun = r.run
+	got := apiCall(t, s, c, "POST", "/api/panel/update/check", "")
+	if !strings.Contains(got, `"newer":true`) || !strings.Contains(got, `"latest":"99.0.0"`) || !strings.Contains(got, `"current":"`+Version+`"`) {
+		t.Fatalf("check: %s", got)
+	}
+	if got := apiCall(t, s, c, "POST", "/api/panel/update/run", ""); !strings.Contains(got, `"ok":true`) || r.n() != 1 {
+		t.Fatalf("run: %s, %d runs", got, r.n())
+	}
+	g.tag = Version
+	if got := apiCall(t, s, c, "POST", "/api/panel/update/run", ""); !strings.Contains(got, `"ok":false`) || r.n() != 1 {
+		t.Fatalf("run with nothing newer: %s, %d runs", got, r.n())
+	}
+}
+
+// Not for everybody: only an administrator updates the server.
+func TestUpdateOnlyForAdmins(t *testing.T) {
+	s, c := newTestServer(t)
+	a, _ := s.db.AdminByUsername("adm")
+	if a == nil {
+		t.Fatal("no admin")
+	}
+	// The test's user is an administrator; the guard is the route's own.
+	if got := apiCall(t, s, c, "POST", "/api/panel/update/check", ""); strings.Contains(got, "только для администраторов") {
+		t.Fatalf("an administrator was refused: %s", got)
+	}
+}

internal/server/handlers_agent.go

@@ -56,6 +56,7 @@ func (s *Server) handlePoll(w http.ResponseWriter, r *http.Request) {
 	msg := s.hub.WaitControl(r.Context().Done(), a.ID, pollHold)
 	// Set after the hold so a setting changed meanwhile reaches the agent now.
 	s.setTunnelHeader(w)
+	s.setUpdateHeaders(w)
 	w.Header().Set(proto.TransportHeader, s.transportOf(a.ID))
 	writeJSON(w, msg)
 }
@@ -83,6 +84,7 @@ func (s *Server) handleAgentConfig(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	s.setTunnelHeader(w)
+	s.setUpdateHeaders(w)
 	w.Header().Set(proto.TransportHeader, s.transportOf(a.ID))
 	w.WriteHeader(http.StatusNoContent)
 }

internal/server/handlers_panel.go

@@ -446,6 +446,7 @@ func (s *Server) handleSettings(w http.ResponseWriter, r *http.Request) {
 		"AIModels":      s.aiModels(),
 		"Search":        s.searchConf(),
 		"ImageKey":      func() string { _, k := s.imageConf(); return k }(),
+		"Auto":          s.autoView(),
 		"DBNow":         dbNow,
 		"DBChosen":      dbChosen,
 		"UfwInstalled":  ufwInstalled,

internal/server/server.go

@@ -65,6 +65,9 @@ type Server struct {
 	wsAgents   wsAgents          // agents on their WebSocket now
 	pinMisses  pinMisses         // wrong PINs per session
 	assets     map[string]string // static file -> hash of its content
+
+	upd    updState                  // the server's own updating
+	updRun func(script []byte) error // runs the install script; the real one unless a test sets it
 }
 
 // New builds the server, parsing embedded templates.
@@ -269,6 +272,11 @@ func (s *Server) Handler() http.Handler {
 	mux.Handle("POST /api/panel/ai/image", s.requireAdmin(s.handleAIImage))
 	mux.Handle("GET /api/panel/ai/image/{job}", s.requireAdmin(s.handleAIImageJob))
 	mux.Handle("POST /settings/ai", s.adminsOnly(s.handleSetAI))
+	mux.Handle("POST /settings/autoupdate", s.adminsOnly(s.handleSetAutoUpdate))
+	mux.Handle("POST /api/panel/update/check", s.adminsOnly(s.handleUpdateCheck))
+	mux.Handle("GET /api/panel/update/offer", s.adminsOnly(s.handleUpdateOffer))
+	mux.Handle("POST /api/panel/update/decline", s.adminsOnly(s.handleUpdateDecline))
+	mux.Handle("POST /api/panel/update/run", s.adminsOnly(s.handleUpdateRun))
 	mux.Handle("POST /settings/db", s.adminsOnly(s.handleSetDB))
 	mux.Handle("POST /settings/db/restart", s.adminsOnly(s.handleRestart))
 	mux.Handle("POST /api/panel/account/keys/begin", s.requireAdmin(s.handleKeyRegisterBegin))

internal/server/web/static/ai.js

@@ -721,12 +721,15 @@
   // the next question (or by note, when done by hand).
   function showResult(text) {
     const el = add('result', '');
-    el.innerHTML = '<details><summary>Результат</summary><pre></pre></details>';
-    el.querySelector('pre').textContent = text;
     // A picture made: shown here, from its marker (kept with the talk, so
-    // it comes back with it) - and what the next edit works on.
+    // it comes back with it) - and what the next edit works on. Its words
+    // are the model's alone: the user sees the picture.
     const m = /\[картинка: (https?:\/\/[^\]\s]+)\]/.exec(text);
-    if (!m) return;
+    if (!m) {
+      el.innerHTML = '<details><summary>Результат</summary><pre></pre></details>';
+      el.querySelector('pre').textContent = text;
+      return;
+    }
     lastPic = m[1];
     const follow = nearBottom();
     const link = document.createElement('a'), img = document.createElement('img');
@@ -736,7 +739,7 @@
     img.onerror = () => { link.classList.add('gone'); link.textContent = 'Картинка больше не открывается'; };
     link.appendChild(img);
     el.classList.add('pic');
-    el.insertBefore(link, el.firstChild);
+    el.appendChild(link);
   }
   // makeImage: a picture asked for in an answer - put at the image service
   // through the server, asked about until it is done. What comes back is

internal/server/web/static/app.css

@@ -963,7 +963,7 @@ dialog.uidlg { width:fit-content; min-width:min(300px, 92vw); max-width:min(560p
 .ai-pic { display:block; overflow:hidden; border:1px solid var(--border); border-radius:12px; background:#0c0f13; line-height:0; }
 .ai-pic img { display:block; width:100%; height:auto; max-height:440px; object-fit:contain; background:#0c0f13; }
 .ai-pic.gone { padding:18px 12px; line-height:1.4; text-align:center; color:var(--muted); font-size:12.5px; }
-.ai-msg.result.pic details { padding:0 4px; }
+
 .ai-msg.result pre { margin:6px 0 2px; max-height:220px; overflow:auto; white-space:pre-wrap; font-size:12px; }
 .ai-cap { font-size:12px; margin-bottom:4px; }
 /* Modes as pills: on - lit in the accent, off - a quiet outline. */
@@ -1156,6 +1156,13 @@ body.no-motion *, body.no-motion *::before, body.no-motion *::after, body.no-mot
 .ai-model-sub { min-width:0; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; color:var(--muted); font-size:12.5px; }
 .ai-model-sub:not(:empty)::before { content:'· '; }
 .ai-model-body { display:grid; gap:10px; min-width:0; padding:0 12px 12px; }
+.ai-form label.check { display:inline-flex; align-items:center; gap:8px; margin:0; color:var(--text); font-size:14px; cursor:pointer; }
+.ai-form label.check input { margin:0; }
+.auto-every { display:flex; align-items:center; gap:8px; }
+.auto-every input[type=number] { width:84px; flex:none; }
+.auto-every select { width:auto; flex:none; }
+.auto-status { font-size:13px; line-height:1.5; }
+.auto-status .bad { color:var(--danger); }
 .ai-model-head { display:flex; align-items:flex-end; gap:8px; margin:2px 0 4px; }
 .ai-model-head .ai-model-name { flex:1; min-width:0; margin:0; }
 .ai-model-head .ai-model-short { flex:none; width:96px; margin:0; }

internal/server/web/static/pages.js

@@ -23,6 +23,30 @@
         }, e => alert('Не скопировалось: ' + e.message));
       });
       if (window.UsersTable) window.UsersTable.mount(root);
+      // Автообновление: look at GitLab now, and update now.
+      const au = root.querySelector('#autoupdate .auto-check');
+      if (au) {
+        const st = root.querySelector('#autoupdate .auto-status'), run = root.querySelector('#autoupdate .auto-run');
+        const post = u => fetch(u, {method: 'POST', credentials: 'same-origin'}).then(r => r.json()).catch(() => ({ok: false, error: 'нет связи с сервером'}));
+        const say = (text, bad) => { st.textContent = ''; const s = document.createElement('span'); s.textContent = text; if (bad) s.className = 'bad'; st.appendChild(s); };
+        au.onclick = async () => {
+          au.disabled = true; say('Проверяю…');
+          const r = await post('/api/panel/update/check');
+          au.disabled = false;
+          if (!r.ok) { say(r.error, true); return; }
+          say('Версия сервера: ' + r.current + ' · на GitLab: ' + r.latest + (r.newer ? ' - вышла новая' : ' - это последняя'));
+          run.hidden = !r.newer;
+        };
+        run.onclick = async () => {
+          if (!await UI.confirm('Обновить сервер сейчас? Панель будет недоступна около минуты.', {ok: 'Обновить'})) return;
+          run.disabled = true; say('Запускаю обновление…');
+          const r = await post('/api/panel/update/run');
+          run.disabled = false;
+          if (!r.ok) { say(r.error, true); return; }
+          run.hidden = true;
+          say('Обновление до ' + r.latest + ' запущено: сервер перезапустится в течение минуты - потом обновите страницу.');
+        };
+      }
       // ИИ-ассистент: a card per model, added from the blank one and taken
       // away by its «Удалить» (the last one stays).
       const list = root.querySelector('.ai-models'), blank = root.querySelector('template.ai-model-new');

internal/server/web/static/ui.js

@@ -50,6 +50,7 @@
     input.value = o.value || '';
     yes.textContent = o.ok || 'OK';
     yes.className = 'ui-yes' + (o.danger ? ' btn danger' : '');
+    dlg.querySelector('.ui-no').textContent = o.cancel || 'Отмена';
     // «Отмена» red, unless «да» is the red one (a delete): never two reds.
     dlg.querySelector('.ui-no').classList.toggle('close', !o.danger);
     return new Promise(done => {

internal/server/web/static/updatenote.js

@@ -0,0 +1,47 @@
+// A new release of the server: an administrator is offered it when they come
+// in - after the PIN, or at once when there is none - once for each tab. The
+// window says the versions and has «Обновить» and «Отказаться»; a refusal is
+// kept for that release (a still newer one asks again). Only when the server
+// is set to look for releases (Настройки › Автообновление).
+(function () {
+  'use strict';
+  var root = document.documentElement;
+  var SHOWN = 'lpra.upd.shown';
+
+  // The PIN lock hides the page until it is unlocked.
+  function whenUnlocked(fn) {
+    if (!root.classList.contains('pin-wait')) { fn(); return; }
+    var mo = new MutationObserver(function () {
+      if (!root.classList.contains('pin-wait')) { mo.disconnect(); fn(); }
+    });
+    mo.observe(root, {attributes: true, attributeFilter: ['class']});
+  }
+  function toast(text, bad) {
+    if (window.FileViews && FileViews.toast) FileViews.toast(text, bad);
+  }
+  function post(url, body) {
+    return fetch(url, {method: 'POST', headers: {'Content-Type': 'application/json'}, credentials: 'same-origin',
+      body: JSON.stringify(body || {})}).then(function (r) { return r.json(); })
+      .catch(function () { return {ok: false, error: 'нет связи с сервером'}; });
+  }
+
+  function offer() {
+    try { if (sessionStorage.getItem(SHOWN) === '1') return; } catch (e) { /* offered again */ }
+    fetch('/api/panel/update/offer', {cache: 'no-store', credentials: 'same-origin'})
+      .then(function (r) { return r.ok ? r.json() : {}; })
+      .then(function (d) {
+        if (!d.offer || !window.UI) return;
+        try { sessionStorage.setItem(SHOWN, '1'); } catch (e) { /* not remembered */ }
+        UI.confirm('Вышла новая версия LPRA {chip}\nОбновить сервер сейчас? Панель будет недоступна около минуты.',
+          {ok: 'Обновить', cancel: 'Отказаться', chip: d.current + ' → ' + d.latest}).then(function (yes) {
+          if (!yes) { post('/api/panel/update/decline', {version: d.latest}); return; }
+          post('/api/panel/update/run').then(function (r) {
+            if (r.ok) toast('Обновление до ' + r.latest + ' запущено: сервер перезапустится в течение минуты - потом обновите страницу');
+            else toast(r.error || 'обновить не получилось', true);
+          });
+        });
+      })
+      .catch(function () { /* no offer */ });
+  }
+  whenUnlocked(offer);
+})();

internal/server/web/templates/app.html

@@ -213,6 +213,7 @@
 <script src="{{asset "account.js"}}"></script>
 <script src="{{asset "machine.js"}}"></script>
 <script src="{{asset "ai.js"}}"></script>
+<script src="{{asset "updatenote.js"}}"></script>
 <script>App.start();</script>
 </body>
 </html>{{end}}

internal/server/web/templates/settings.html

@@ -212,6 +212,36 @@
     </form>
   </div>
 
+  <div class="card" id="autoupdate">
+    <h2>Автообновление</h2>
+    <form method="post" action="/settings/autoupdate" class="ai-form">
+      <input type="hidden" name="csrf" value="{{.CSRF}}">
+      {{/* The same spoilers as the assistant's. */}}
+      <details class="ai-search"><summary class="ai-model-sum"><span class="ai-model-title">Автообновление клиентов</span><span class="ai-model-sub">{{if .Auto.AgentOn}}каждые {{.Auto.AgentEvery}} {{if eq .Auto.AgentUnit "d"}}сут.{{else if eq .Auto.AgentUnit "h"}}ч.{{else}}мин.{{end}}{{else}}выключено{{end}}</span></summary>
+      <div class="ai-model-body">
+      <p class="muted" style="margin:0">Клиенты раз в указанное время сверяют свою версию с версией сервера и, если у сервера новее, обновляются сами - так же, как по кнопке «Обновить». Нужны права root или sudo без пароля; агентам старше 0.2.5 один раз обновиться придётся вручную.</p>
+      <label class="check"><input type="checkbox" name="agent_auto" value="1"{{if .Auto.AgentOn}} checked{{end}}> Включить автообновление клиентов</label>
+      <div class="auto-every"><span class="muted">Проверять раз в</span>
+        <input type="number" name="agent_every" min="1" max="999" value="{{.Auto.AgentEvery}}">
+        <select name="agent_unit"><option value="min"{{if eq .Auto.AgentUnit "min"}} selected{{end}}>минут</option><option value="h"{{if eq .Auto.AgentUnit "h"}} selected{{end}}>часов</option><option value="d"{{if eq .Auto.AgentUnit "d"}} selected{{end}}>суток</option></select></div>
+      </div></details>
+      <details class="ai-search"><summary class="ai-model-sum"><span class="ai-model-title">Автообновление сервера</span><span class="ai-model-sub">{{if .Auto.ServerOn}}каждые {{.Auto.ServerEvery}} {{if eq .Auto.ServerUnit "d"}}сут.{{else if eq .Auto.ServerUnit "h"}}ч.{{else}}мин.{{end}}{{else}}выключено{{end}} · сейчас {{.Auto.Status.Current}}</span></summary>
+      <div class="ai-model-body">
+      <p class="muted" style="margin:0">Сервер раз в указанное время сверяет свою версию с последним релизом на GitLab. Если вышел новый, администратору при входе (после PIN) показывается окно: версия и кнопки «Обновить» и «Отказаться». «Обновить» запускает тот же скрипт, что и вручную: <code>wget -qO- https://gitlab.com/itzredtea/lpra/-/raw/main/server-install.sh | sudo sh</code> - от root, поэтому нужны root и systemd; панель при этом недоступна около минуты.</p>
+      <label class="check"><input type="checkbox" name="server_auto" value="1"{{if .Auto.ServerOn}} checked{{end}}> Предлагать обновление сервера при входе</label>
+      <div class="auto-every"><span class="muted">Проверять раз в</span>
+        <input type="number" name="server_every" min="1" max="999" value="{{.Auto.ServerEvery}}">
+        <select name="server_unit"><option value="min"{{if eq .Auto.ServerUnit "min"}} selected{{end}}>минут</option><option value="h"{{if eq .Auto.ServerUnit "h"}} selected{{end}}>часов</option><option value="d"{{if eq .Auto.ServerUnit "d"}} selected{{end}}>суток</option></select></div>
+      <div class="auto-status muted" aria-live="polite">Версия сервера: <b>{{.Auto.Status.Current}}</b>{{if .Auto.Status.Latest}} · на GitLab: <b>{{.Auto.Status.Latest}}</b>{{end}}{{if .Auto.Status.Checked}} · проверено {{.Auto.Status.Checked}}{{end}}{{if .Auto.Status.Error}}<br><span class="bad">{{.Auto.Status.Error}}</span>{{end}}</div>
+      <div class="row">
+        <button type="button" class="btn ghost small auto-check">Проверить сейчас</button>
+        <button type="button" class="btn small auto-run"{{if not .Auto.Status.Newer}} hidden{{end}}>Обновить сейчас</button>
+      </div>
+      </div></details>
+      <div><button type="submit">Сохранить</button></div>
+    </form>
+  </div>
+
   <div class="card">
     <h2>Enroll-секрет</h2>
     <p class="muted">Общий секрет для регистрации новых агентов.</p>

internal/server/wsagent.go

@@ -98,7 +98,8 @@ func (s *Server) handleAgentWS(w http.ResponseWriter, r *http.Request) {
 		return wsjson.Write(wctx, conn, m)
 	}
 	cfg := func() proto.WSMsg {
-		return proto.WSMsg{T: "cfg", Tunnel: s.tunnelAdvert(), Transport: s.transportOf(a.ID), Fallback: s.db.DirectAddress(), Main: s.db.HostAddress()}
+		return proto.WSMsg{T: "cfg", Tunnel: s.tunnelAdvert(), Transport: s.transportOf(a.ID), Fallback: s.db.DirectAddress(), Main: s.db.HostAddress(),
+			AutoUpdate: s.agentAutoMinutes(), ServerVersion: Version}
 	}
 	if send(cfg()) != nil {
 		return