fix: make update banner dynamic instead of static at startup

yottahmd · yottahmd · commit a54fee6d68d2 · 2026-03-05T16:52:09.000+09:00
The update check was only evaluated once at server startup and injected
as static values into the HTML template. Long-running servers would
never show the update banner even if new versions were released.

Now the template functions read from the cache store on every page load,
and a periodic background goroutine refreshes the cache every 24 hours.
diff --git a/internal/service/frontend/server.go b/internal/service/frontend/server.go
@@ -93,6 +93,7 @@ type Server struct {
 	dagStore           exec.DAGStore
 	licenseManager     *license.Manager
 	remoteNodeResolver *remotenode.Resolver
+	upgradeStore       upgrade.CacheStore
 }
 
 // ServerOption is a functional option for configuring the Server.
@@ -312,13 +313,6 @@ func NewServer(ctx context.Context, cfg *config.Config, dr exec.DAGStore, drs ex
 		logger.Warn(ctx, "Failed to create upgrade check store", tag.Error(err))
 	}
 
-	// Check for updates asynchronously (populates cache for next startup)
-	if upgradeStore != nil {
-		go func() { _, _ = upgrade.CheckAndUpdateCache(upgradeStore, config.Version) }()
-	}
-
-	updateAvailable, latestVersion := getUpdateInfo(upgradeStore)
-
 	// Note: SSO/OIDC gating is applied after opts are processed (see below)
 
 	srv := &Server{
@@ -333,6 +327,7 @@ func NewServer(ctx context.Context, cfg *config.Config, dr exec.DAGStore, drs ex
 		metricsRegistry:    mr,
 		dagStore:           dr,
 		remoteNodeResolver: remoteNodeResolver,
+		upgradeStore:       upgradeStore,
 		funcsConfig: funcsConfig{
 			NavbarColor:           cfg.UI.NavbarColor,
 			NavbarTitle:           cfg.UI.NavbarTitle,
@@ -350,8 +345,7 @@ func NewServer(ctx context.Context, cfg *config.Config, dr exec.DAGStore, drs ex
 			TerminalEnabled:       cfg.Server.Terminal.Enabled && authSvc != nil,
 			GitSyncEnabled:        cfg.GitSync.Enabled,
 			SetupRequiredChecker:  &setupChecker{authSvc: authSvc, fallback: setupRequired},
-			UpdateAvailable:       updateAvailable,
-			LatestVersion:         latestVersion,
+			UpdateChecker:         &updateChecker{store: upgradeStore},
 			AgentEnabledChecker:   agentConfigStore,
 		},
 	}
@@ -420,12 +414,16 @@ func NewServer(ctx context.Context, cfg *config.Config, dr exec.DAGStore, drs ex
 	return srv, nil
 }
 
-// getUpdateInfo returns update availability and latest version from cache.
-func getUpdateInfo(store upgrade.CacheStore) (updateAvailable bool, latestVersion string) {
-	if store == nil {
+// updateChecker implements UpdateChecker by reading from the upgrade cache store.
+type updateChecker struct {
+	store upgrade.CacheStore
+}
+
+func (u *updateChecker) GetUpdateInfo() (bool, string) {
+	if u.store == nil {
 		return false, ""
 	}
-	cache := upgrade.GetCachedUpdateInfo(store)
+	cache := upgrade.GetCachedUpdateInfo(u.store)
 	if cache == nil {
 		return false, ""
 	}
@@ -842,12 +840,36 @@ func (srv *Server) Serve(ctx context.Context) error {
 	metrics.StartUptime(ctx)
 	logger.Info(ctx, "Server is starting", tag.Addr(addr))
 
+	srv.startPeriodicUpdateCheck(ctx)
+
 	go srv.startServer(ctx)
 	srv.setupGracefulShutdown(ctx)
 
 	return nil
 }
 
+// startPeriodicUpdateCheck runs an initial update check and then repeats
+// every CacheTTL interval so that long-running servers pick up new releases.
+func (srv *Server) startPeriodicUpdateCheck(ctx context.Context) {
+	if srv.upgradeStore == nil {
+		return
+	}
+	go func() {
+		_, _ = upgrade.CheckAndUpdateCache(srv.upgradeStore, config.Version)
+
+		ticker := time.NewTicker(upgrade.CacheTTL)
+		defer ticker.Stop()
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-ticker.C:
+				_, _ = upgrade.CheckAndUpdateCache(srv.upgradeStore, config.Version)
+			}
+		}
+	}()
+}
+
 func (srv *Server) configureAPIPath() string {
 	apiV1BasePath := path.Join(srv.config.Server.BasePath, "api/v1")
 	return ensureLeadingSlash(apiV1BasePath)
diff --git a/internal/service/frontend/templates.go b/internal/service/frontend/templates.go
@@ -62,6 +62,12 @@ type SetupRequiredChecker interface {
 	IsSetupRequired(ctx context.Context) bool
 }
 
+// UpdateChecker provides dynamic update availability for template rendering.
+// Called on every HTML page render so the banner reflects the latest cached check.
+type UpdateChecker interface {
+	GetUpdateInfo() (updateAvailable bool, latestVersion string)
+}
+
 // AgentEnabledChecker provides the agent enabled status for template rendering.
 type AgentEnabledChecker interface {
 	IsEnabled(ctx context.Context) bool
@@ -85,8 +91,7 @@ type funcsConfig struct {
 	GitSyncEnabled        bool
 
 	SetupRequiredChecker SetupRequiredChecker
-	UpdateAvailable      bool
-	LatestVersion        string
+	UpdateChecker        UpdateChecker
 	AgentEnabledChecker  AgentEnabledChecker
 	LicenseChecker       license.Checker
 	LicenseManager       *license.Manager
@@ -130,8 +135,20 @@ func defaultFunctions(cfg *funcsConfig) template.FuncMap {
 			}
 			return boolStr(cfg.SetupRequiredChecker.IsSetupRequired(context.Background()))
 		},
-		"updateAvailable": func() string { return boolStr(cfg.UpdateAvailable) },
-		"latestVersion":   func() string { return cfg.LatestVersion },
+		"updateAvailable": func() string {
+			if cfg.UpdateChecker == nil {
+				return "false"
+			}
+			available, _ := cfg.UpdateChecker.GetUpdateInfo()
+			return boolStr(available)
+		},
+		"latestVersion": func() string {
+			if cfg.UpdateChecker == nil {
+				return ""
+			}
+			_, version := cfg.UpdateChecker.GetUpdateInfo()
+			return version
+		},
 
 		// License functions
 		"licenseValid": func() string {
