[ws-daemon] Serve IWS on restart

Author: csweichel

components/ws-daemon/pkg/content/service.go

@@ -754,9 +754,13 @@ func workspaceLifecycleHooks(cfg Config, kubernetesNamespace string, workspaceEx
 		return nil
 	}
 
+	// startIWS starts the in-workspace service for a workspace. This lifecycle hook is idempotent, hence can - and must -
+	// be called on initialization and ready. The on-ready hook exists only to support ws-daemon restarts.
+	startIWS := iws.ServeWorkspace(uidmapper, api.FSShiftMethod(cfg.UserNamespaces.FSShift))
+
 	return map[session.WorkspaceState][]session.WorkspaceLivecycleHook{
-		session.WorkspaceInitializing: {setupWorkspace, iws.ServeWorkspace(uidmapper, api.FSShiftMethod(cfg.UserNamespaces.FSShift))},
-		session.WorkspaceReady:        {setupWorkspace},
+		session.WorkspaceInitializing: {setupWorkspace, startIWS},
+		session.WorkspaceReady:        {setupWorkspace, startIWS},
 		session.WorkspaceDisposing:    {iws.StopServingWorkspace},
 	}
 }

components/ws-daemon/pkg/iws/iws.go

@@ -78,6 +78,10 @@ var (
 // ServeWorkspace establishes the IWS server for a workspace
 func ServeWorkspace(uidmapper *Uidmapper, fsshift api.FSShiftMethod) func(ctx context.Context, ws *session.Workspace) error {
 	return func(ctx context.Context, ws *session.Workspace) (err error) {
+		if _, running := ws.NonPersistentAttrs[session.AttrWorkspaceServer]; running {
+			return nil
+		}
+
 		//nolint:ineffassign
 		span, ctx := opentracing.StartSpanFromContext(ctx, "iws.ServeWorkspace")
 		defer tracing.FinishSpan(span, &err)