feat(admin): add MokoGitea update checker (#74)

Replace removed upstream Gitea update checker with MokoGitea-native
version that checks our own releases API.

- New module: modules/updatechecker/ — fetches latest release from
  git.mokoconsulting.tech, compares semver, caches result
- Cron task: runs every 24h (and at startup)
- Admin dashboard: shows green banner when update available
- Configurable via [update_checker] in app.ini

Closes #74

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

modules/setting/setting.go

@@ -28,6 +28,15 @@ var (
 	CfgProvider ConfigProvider
 	IsWindows   bool
 
+	// UpdateChecker configuration for MokoGitea version checking
+	UpdateChecker = struct {
+		Enabled  bool
+		Endpoint string
+	}{
+		Enabled:  true,
+		Endpoint: "https://git.mokoconsulting.tech/api/v1/repos/MokoConsulting/MokoGitea/releases/latest",
+	}
+
 	// IsInTesting indicates whether the testing is running (unit test or integration test). It can be used for:
 	// * Skip nonsense error logs during testing caused by unreliable code (TODO: this is only a temporary solution, we should make the test code more reliable)
 	// * Panic in dev or testing mode to make the problem more obvious and easier to debug
@@ -158,9 +167,16 @@ func loadCommonSettingsFrom(cfg ConfigProvider) error {
 	loadMarkupFrom(cfg)
 	loadGlobalLockFrom(cfg)
 	loadOtherFrom(cfg)
+	loadUpdateCheckerFrom(cfg)
 	return nil
 }
 
+func loadUpdateCheckerFrom(cfg ConfigProvider) {
+	sec := cfg.Section("update_checker")
+	UpdateChecker.Enabled = sec.Key("ENABLED").MustBool(true)
+	UpdateChecker.Endpoint = sec.Key("ENDPOINT").MustString(UpdateChecker.Endpoint)
+}
+
 func loadRunModeFrom(rootCfg ConfigProvider) {
 	rootSec := rootCfg.Section("")
 	RunUser = rootSec.Key("RUN_USER").MustString(user.CurrentUsername())

modules/updatechecker/updatechecker.go

@@ -0,0 +1,106 @@
+// Copyright 2026 Moko Consulting <hello@mokoconsulting.tech>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package updatechecker
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// UpdateInfo holds the result of the latest update check.
+type UpdateInfo struct {
+	UpdateAvailable bool
+	LatestVersion   string
+	ReleaseURL      string
+	CheckedAt       time.Time
+}
+
+var (
+	cachedInfo *UpdateInfo
+	mu         sync.RWMutex
+)
+
+// giteaRelease is the subset of Gitea's release API response we need.
+type giteaRelease struct {
+	TagName string `json:"tag_name"`
+	HTMLURL string `json:"html_url"`
+	Draft   bool   `json:"draft"`
+}
+
+// CheckForUpdate fetches the latest release from the configured endpoint
+// and compares it to the running version.
+func CheckForUpdate() error {
+	if !setting.UpdateChecker.Enabled || setting.UpdateChecker.Endpoint == "" {
+		return nil
+	}
+
+	client := &http.Client{Timeout: 15 * time.Second}
+	resp, err := client.Get(setting.UpdateChecker.Endpoint)
+	if err != nil {
+		return fmt.Errorf("update check failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("update check returned status %d", resp.StatusCode)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("reading update response: %w", err)
+	}
+
+	var release giteaRelease
+	if err := json.Unmarshal(body, &release); err != nil {
+		return fmt.Errorf("parsing update response: %w", err)
+	}
+
+	if release.Draft || release.TagName == "" {
+		return nil
+	}
+
+	latestVersion := strings.TrimPrefix(release.TagName, "v")
+	currentVersion := setting.AppVer
+
+	info := &UpdateInfo{
+		LatestVersion: latestVersion,
+		ReleaseURL:    release.HTMLURL,
+		CheckedAt:     time.Now(),
+	}
+
+	// Simple comparison: if latest != current, update is available.
+	// This handles both upgrades and the case where versions differ
+	// in any way (patch, upstream bump, etc.)
+	info.UpdateAvailable = latestVersion != "" && !strings.HasPrefix(currentVersion, latestVersion)
+
+	mu.Lock()
+	cachedInfo = info
+	mu.Unlock()
+
+	if info.UpdateAvailable {
+		log.Info("MokoGitea update available: %s (current: %s)", latestVersion, currentVersion)
+	} else {
+		log.Debug("MokoGitea is up to date: %s", currentVersion)
+	}
+
+	return nil
+}
+
+// GetUpdateInfo returns the cached update check result.
+func GetUpdateInfo() *UpdateInfo {
+	mu.RLock()
+	defer mu.RUnlock()
+	if cachedInfo == nil {
+		return &UpdateInfo{}
+	}
+	return cachedInfo
+}

routers/web/admin/admin.go

@@ -21,6 +21,7 @@ import (
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/updatechecker"
 	"code.gitea.io/gitea/modules/templates"
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/services/context"
@@ -135,8 +136,13 @@ func prepareStartupProblemsAlert(ctx *context.Context) {
 func Dashboard(ctx *context.Context) {
 	ctx.Data["Title"] = ctx.Tr("admin.dashboard")
 	ctx.Data["PageIsAdminDashboard"] = true
-	// MokoGitea: upstream update checker removed — this is an independent fork
-	ctx.Data["NeedUpdate"] = false
+
+	// MokoGitea update checker
+	info := updatechecker.GetUpdateInfo()
+	ctx.Data["NeedUpdate"] = info.UpdateAvailable
+	ctx.Data["LatestVersion"] = info.LatestVersion
+	ctx.Data["ReleaseURL"] = info.ReleaseURL
+
 	updateSystemStatus()
 	ctx.Data["SysStatus"] = sysStatus
 	ctx.Data["SSH"] = setting.SSH

services/cron/tasks_basic.go

@@ -13,6 +13,7 @@ import (
 	"code.gitea.io/gitea/models/webhook"
 	"code.gitea.io/gitea/modules/git/gitcmd"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/updatechecker"
 	"code.gitea.io/gitea/services/auth"
 	"code.gitea.io/gitea/services/migrations"
 	mirror_service "code.gitea.io/gitea/services/mirror"
@@ -183,4 +184,17 @@ func initBasicTasks() {
 		registerCleanupPackages()
 	}
 	registerSyncRepoLicenses()
+	if setting.UpdateChecker.Enabled {
+		registerUpdateChecker()
+	}
+}
+
+func registerUpdateChecker() {
+	RegisterTaskFatal("update_checker", &BaseConfig{
+		Enabled:    true,
+		RunAtStart: true,
+		Schedule:   "@every 24h",
+	}, func(ctx context.Context, _ *user_model.User, _ Config) error {
+		return updatechecker.CheckForUpdate()
+	})
 }

templates/admin/dashboard.tmpl

@@ -1,5 +1,12 @@
 {{template "admin/layout_head" (dict "pageClass" "admin dashboard")}}
 	<div class="admin-setting-content">
+		{{if .NeedUpdate}}
+		<div class="ui positive message">
+			<div class="header">{{svg "octicon-info"}} MokoGitea Update Available</div>
+			<p>A new version <strong>{{.LatestVersion}}</strong> is available.
+			{{if .ReleaseURL}}<a href="{{.ReleaseURL}}" target="_blank" rel="noopener noreferrer">View release notes</a>{{end}}</p>
+		</div>
+		{{end}}
 		<h4 class="ui top attached header">
 			{{ctx.Locale.Tr "admin.dashboard.maintenance_operations"}}
 		</h4>