fix: allow access to unhealthy/initializing apps (#12086)

coderd/workspaceapps/db.go

@@ -198,11 +198,9 @@ func (p *DBTokenProvider) Issue(ctx context.Context, rw http.ResponseWriter, r *
 		return nil, "", false
 	}
 
-	// Check that the app is healthy.
-	if dbReq.AppHealth != "" && dbReq.AppHealth != database.WorkspaceAppHealthDisabled && dbReq.AppHealth != database.WorkspaceAppHealthHealthy {
-		WriteWorkspaceAppOffline(p.Logger, p.DashboardURL, rw, r, &appReq, fmt.Sprintf("App health is %q, not %q", dbReq.AppHealth, database.WorkspaceAppHealthHealthy))
-		return nil, "", false
-	}
+	// This is where we used to check app health, but we don't do that anymore
+	// in case there are bugs with the healthcheck code that lock users out of
+	// their apps completely.
 
 	// As a sanity check, ensure the token we just made is valid for this
 	// request.

coderd/workspaceapps/db_test.go

@@ -37,9 +37,12 @@ func Test_ResolveRequest(t *testing.T) {
 		appNameAuthed     = "app-authed"
 		appNamePublic     = "app-public"
 		appNameInvalidURL = "app-invalid-url"
-		appNameUnhealthy  = "app-unhealthy"
+		// Users can access unhealthy and initializing apps (as of 2024-02).
+		appNameUnhealthy    = "app-unhealthy"
+		appNameInitializing = "app-initializing"
 
 		// This agent will never connect, so it will never become "connected".
+		// Users cannot access unhealthy agents.
 		agentNameUnhealthy    = "agent-unhealthy"
 		appNameAgentUnhealthy = "app-agent-unhealthy"
 
@@ -55,6 +58,15 @@ func Test_ResolveRequest(t *testing.T) {
 		w.WriteHeader(http.StatusInternalServerError)
 		_, _ = w.Write([]byte("unhealthy"))
 	}))
+	t.Cleanup(unhealthySrv.Close)
+
+	// Start a listener for a server that never responds.
+	initializingServer, err := net.Listen("tcp", "localhost:0")
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		_ = initializingServer.Close()
+	})
+	initializingURL := fmt.Sprintf("http://%s", initializingServer.Addr().String())
 
 	deploymentValues := coderdtest.DeploymentValues(t)
 	deploymentValues.DisablePathApps = false
@@ -82,7 +94,7 @@ func Test_ResolveRequest(t *testing.T) {
 	})
 
 	ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitMedium)
-	defer cancel()
+	t.Cleanup(cancel)
 
 	firstUser := coderdtest.CreateFirstUser(t, client)
 	me, err := client.User(ctx, codersdk.Me)
@@ -143,6 +155,17 @@ func Test_ResolveRequest(t *testing.T) {
 											Threshold: 1,
 										},
 									},
+									{
+										Slug:         appNameInitializing,
+										DisplayName:  appNameInitializing,
+										SharingLevel: proto.AppSharingLevel_PUBLIC,
+										Url:          appURL,
+										Healthcheck: &proto.Healthcheck{
+											Url:       initializingURL,
+											Interval:  30,
+											Threshold: 1000,
+										},
+									},
 								},
 							},
 							{
@@ -805,7 +828,55 @@ func Test_ResolveRequest(t *testing.T) {
 		require.Contains(t, bodyStr, `Agent state is "`)
 	})
 
-	t.Run("UnhealthyApp", func(t *testing.T) {
+	// Initializing apps are now permitted to connect anyways. This wasn't
+	// always the case, but we're testing the behavior to ensure it doesn't
+	// change back accidentally.
+	t.Run("InitializingAppPermitted", func(t *testing.T) {
+		t.Parallel()
+
+		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitShort)
+		defer cancel()
+
+		agent, err := client.WorkspaceAgent(ctx, agentID)
+		require.NoError(t, err)
+
+		for _, app := range agent.Apps {
+			if app.Slug == appNameInitializing {
+				t.Log("app is", app.Health)
+				require.Equal(t, codersdk.WorkspaceAppHealthInitializing, app.Health)
+				break
+			}
+		}
+
+		req := (workspaceapps.Request{
+			AccessMethod:      workspaceapps.AccessMethodPath,
+			BasePath:          "/app",
+			UsernameOrID:      me.Username,
+			WorkspaceNameOrID: workspace.Name,
+			AgentNameOrID:     agentName,
+			AppSlugOrPort:     appNameInitializing,
+		}).Normalize()
+
+		rw := httptest.NewRecorder()
+		r := httptest.NewRequest("GET", "/app", nil)
+		r.Header.Set(codersdk.SessionTokenHeader, client.SessionToken())
+
+		token, ok := workspaceapps.ResolveRequest(rw, r, workspaceapps.ResolveRequestOptions{
+			Logger:              api.Logger,
+			SignedTokenProvider: api.WorkspaceAppsProvider,
+			DashboardURL:        api.AccessURL,
+			PathAppBaseURL:      api.AccessURL,
+			AppHostname:         api.AppHostname,
+			AppRequest:          req,
+		})
+		require.True(t, ok, "ResolveRequest failed, should pass even though app is initializing")
+		require.NotNil(t, token)
+	})
+
+	// Unhealthy apps are now permitted to connect anyways. This wasn't always
+	// the case, but we're testing the behavior to ensure it doesn't change back
+	// accidentally.
+	t.Run("UnhealthyAppPermitted", func(t *testing.T) {
 		t.Parallel()
 
 		require.Eventually(t, func() bool {
@@ -850,17 +921,7 @@ func Test_ResolveRequest(t *testing.T) {
 			AppHostname:         api.AppHostname,
 			AppRequest:          req,
 		})
-		require.False(t, ok, "request succeeded even though app is unhealthy")
-		require.Nil(t, token)
-
-		w := rw.Result()
-		defer w.Body.Close()
-		require.Equal(t, http.StatusBadGateway, w.StatusCode)
-
-		body, err := io.ReadAll(w.Body)
-		require.NoError(t, err)
-		bodyStr := string(body)
-		bodyStr = strings.ReplaceAll(bodyStr, """, `"`)
-		require.Contains(t, bodyStr, `App health is "unhealthy"`)
+		require.True(t, ok, "ResolveRequest failed, should pass even though app is unhealthy")
+		require.NotNil(t, token)
 	})
 }

coderd/workspaceapps/request.go

@@ -198,9 +198,6 @@ type databaseRequest struct {
 	// AppURL is the resolved URL to the workspace app. This is only set for non
 	// terminal requests.
 	AppURL *url.URL
-	// AppHealth is the health of the app. For terminal requests, this is always
-	// database.WorkspaceAppHealthHealthy.
-	AppHealth database.WorkspaceAppHealth
 	// AppSharingLevel is the sharing level of the app. This is forced to be set
 	// to AppSharingLevelOwner if the access method is terminal.
 	AppSharingLevel database.AppSharingLevel
@@ -292,7 +289,6 @@ func (r Request) getDatabase(ctx context.Context, db database.Store) (*databaseR
 		agentNameOrID         = r.AgentNameOrID
 		appURL                string
 		appSharingLevel       database.AppSharingLevel
-		appHealth             = database.WorkspaceAppHealthDisabled
 		portUint, portUintErr = strconv.ParseUint(r.AppSlugOrPort, 10, 16)
 	)
 	if portUintErr == nil {
@@ -331,7 +327,6 @@ func (r Request) getDatabase(ctx context.Context, db database.Store) (*databaseR
 					appSharingLevel = database.AppSharingLevelOwner
 				}
 				appURL = app.Url.String
-				appHealth = app.Health
 				break
 			}
 		}
@@ -377,7 +372,6 @@ func (r Request) getDatabase(ctx context.Context, db database.Store) (*databaseR
 		Workspace:       workspace,
 		Agent:           agent,
 		AppURL:          appURLParsed,
-		AppHealth:       appHealth,
 		AppSharingLevel: appSharingLevel,
 	}, nil
 }
@@ -430,7 +424,6 @@ func (r Request) getDatabaseTerminal(ctx context.Context, db database.Store) (*d
 		Workspace:       workspace,
 		Agent:           agent,
 		AppURL:          nil,
-		AppHealth:       database.WorkspaceAppHealthHealthy,
 		AppSharingLevel: database.AppSharingLevelOwner,
 	}, nil
 }

site/src/modules/resources/AppLink/AppLink.tsx

@@ -61,12 +61,16 @@ export const AppLink: FC<AppLinkProps> = ({ app, workspace, agent }) => {
     app,
   );
 
+  // canClick is ONLY false when it's a subdomain app and the admin hasn't
+  // enabled wildcard access URL or the session token is being fetched.
+  //
+  // To avoid bugs in the healthcheck code locking users out of apps, we no
+  // longer block access to apps if they are unhealthy/initializing.
   let canClick = true;
   let icon = <BaseIcon app={app} />;
 
   let primaryTooltip = "";
   if (app.health === "initializing") {
-    canClick = false;
     icon = (
       // This is a hack to make the spinner appear in the center of the start
       // icon space
@@ -85,7 +89,6 @@ export const AppLink: FC<AppLinkProps> = ({ app, workspace, agent }) => {
     primaryTooltip = "Initializing...";
   }
   if (app.health === "unhealthy") {
-    canClick = false;
     icon = <ErrorOutlineIcon css={{ color: theme.palette.warning.light }} />;
     primaryTooltip = "Unhealthy";
   }