fix(api): Allow workspace agent coordinate to report disconnect (coder#6152)

mafredri · web-flow · commit 2dbe00ae449e · 2023-02-10T20:23:02.000+02:00
diff --git a/coderd/coderd.go b/coderd/coderd.go
@@ -230,7 +230,11 @@ func New(options *Options) *API {
 	staticHandler = httpmw.HSTS(staticHandler, options.StrictTransportSecurityCfg)
 
 	r := chi.NewRouter()
+	ctx, cancel := context.WithCancel(context.Background())
 	api := &API{
+		ctx:    ctx,
+		cancel: cancel,
+
 		ID:          uuid.New(),
 		Options:     options,
 		RootHandler: r,
@@ -676,6 +680,11 @@ func New(options *Options) *API {
 }
 
 type API struct {
+	// ctx is canceled immediately on shutdown, it can be used to abort
+	// interruptible tasks.
+	ctx    context.Context
+	cancel context.CancelFunc
+
 	*Options
 	// ID is a uniquely generated ID on initialization.
 	// This is used to associate objects with a specific
@@ -710,6 +719,8 @@ type API struct {
 
 // Close waits for all WebSocket connections to drain before returning.
 func (api *API) Close() error {
+	api.cancel()
+
 	api.WebsocketWaitMutex.Lock()
 	api.WebsocketWaitGroup.Wait()
 	api.WebsocketWaitMutex.Unlock()
diff --git a/coderd/workspaceagents.go b/coderd/workspaceagents.go
@@ -601,7 +601,7 @@ func (api *API) workspaceAgentCoordinate(rw http.ResponseWriter, r *http.Request
 		Valid: true,
 	}
 	disconnectedAt := workspaceAgent.DisconnectedAt
-	updateConnectionTimes := func() error {
+	updateConnectionTimes := func(ctx context.Context) error {
 		err = api.Database.UpdateWorkspaceAgentConnectionByID(ctx, database.UpdateWorkspaceAgentConnectionByIDParams{
 			ID:               workspaceAgent.ID,
 			FirstConnectedAt: firstConnectedAt,
@@ -620,15 +620,23 @@ func (api *API) workspaceAgentCoordinate(rw http.ResponseWriter, r *http.Request
 	}
 
 	defer func() {
+		// If connection closed then context will be canceled, try to
+		// ensure our final update is sent. By waiting at most the agent
+		// inactive disconnect timeout we ensure that we don't block but
+		// also guarantee that the agent will be considered disconnected
+		// by normal status check.
+		ctx, cancel := context.WithTimeout(api.ctx, api.AgentInactiveDisconnectTimeout)
+		defer cancel()
+
 		disconnectedAt = sql.NullTime{
 			Time:  database.Now(),
 			Valid: true,
 		}
-		_ = updateConnectionTimes()
-		_ = api.Pubsub.Publish(watchWorkspaceChannel(build.WorkspaceID), []byte{})
+		_ = updateConnectionTimes(ctx)
+		api.publishWorkspaceUpdate(ctx, build.WorkspaceID)
 	}()
 
-	err = updateConnectionTimes()
+	err = updateConnectionTimes(ctx)
 	if err != nil {
 		_ = conn.Close(websocket.StatusGoingAway, err.Error())
 		return
@@ -668,7 +676,7 @@ func (api *API) workspaceAgentCoordinate(rw http.ResponseWriter, r *http.Request
 			Time:  database.Now(),
 			Valid: true,
 		}
-		err = updateConnectionTimes()
+		err = updateConnectionTimes(ctx)
 		if err != nil {
 			_ = conn.Close(websocket.StatusGoingAway, err.Error())
 			return
