feat: signals plugins

next try after #18153 without any external dependencies and only supporting websocket. missing tests and necessary documentation but will work on those after initial comments if this would be proper way to go forward. already planning for the notification plugins on top of this. Signed-off-by: Heikki Hellgren <heikki.hellgren@op.fi>
2023-12-04 12:36:50 +02:00
parent 04d94dc3d0
commit 047beadd9d
38 changed files with 1308 additions and 7 deletions
@@ -0,0 +1,7 @@
+---
+'@backstage/plugin-signals-backend': patch
+'@backstage/plugin-signals-react': patch
+'@backstage/plugin-signals-node': patch
+---
+
+Add support to subscribe and publish messages through signals plugins
@@ -72,6 +72,8 @@
    "@backstage/plugin-search-backend-module-techdocs": "workspace:^",
    "@backstage/plugin-search-backend-node": "workspace:^",
    "@backstage/plugin-search-common": "workspace:^",
+    "@backstage/plugin-signals-backend": "workspace:^",
+    "@backstage/plugin-signals-node": "workspace:^",
    "@backstage/plugin-tech-insights-backend": "workspace:^",
    "@backstage/plugin-tech-insights-backend-module-jsonfc": "workspace:^",
    "@backstage/plugin-tech-insights-node": "workspace:^",
@@ -26,19 +26,19 @@ import Router from 'express-promise-router';
 import {
  CacheManager,
  createServiceBuilder,
+  DatabaseManager,
  getRootLogger,
+  HostDiscovery,
  loadBackendConfig,
  notFoundHandler,
-  DatabaseManager,
-  HostDiscovery,
+  ServerTokenManager,
  UrlReaders,
  useHotMemoize,
-  ServerTokenManager,
 } from '@backstage/backend-common';
 import { TaskScheduler } from '@backstage/backend-tasks';
 import { Config } from '@backstage/config';
 import healthcheck from './plugins/healthcheck';
-import { metricsInit, metricsHandler } from './metrics';
+import { metricsHandler, metricsInit } from './metrics';
 import auth from './plugins/auth';
 import azureDevOps from './plugins/azure-devops';
 import catalog from './plugins/catalog';
@@ -65,6 +65,7 @@ import lighthouse from './plugins/lighthouse';
 import linguist from './plugins/linguist';
 import devTools from './plugins/devtools';
 import nomad from './plugins/nomad';
+import signals from './plugins/signals';
 import { PluginEnvironment } from './types';
 import { ServerPermissionClient } from '@backstage/plugin-permission-node';
 import { DefaultIdentityClient } from '@backstage/plugin-auth-node';
@@ -172,6 +173,7 @@ async function main() {
  const linguistEnv = useHotMemoize(module, () => createEnv('linguist'));
  const devToolsEnv = useHotMemoize(module, () => createEnv('devtools'));
  const nomadEnv = useHotMemoize(module, () => createEnv('nomad'));
+  const signalsEnv = useHotMemoize(module, () => createEnv('signals'));

  const apiRouter = Router();
  apiRouter.use('/catalog', await catalog(catalogEnv));
@@ -198,6 +200,7 @@ async function main() {
  apiRouter.use('/linguist', await linguist(linguistEnv));
  apiRouter.use('/devtools', await devTools(devToolsEnv));
  apiRouter.use('/nomad', await nomad(nomadEnv));
+  apiRouter.use('/signals', await signals(signalsEnv));
  apiRouter.use(notFoundHandler());

  await lighthouse(lighthouseEnv);
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { Router } from 'express';
+import { createRouter } from '@backstage/plugin-signals-backend';
+import { SignalsService } from '@backstage/plugin-signals-node';
+import { PluginEnvironment } from '../types';
+
+export default async function createPlugin(
+  env: PluginEnvironment,
+): Promise<Router> {
+  const service = SignalsService.create({
+    logger: env.logger,
+    identity: env.identity,
+    eventBroker: env.eventBroker,
+  });
+
+  setInterval(() => {
+    console.log('publishing');
+    service.publish('*', { hello: 'world' });
+  }, 5000);
+
+  return await createRouter({
+    logger: env.logger,
+    service,
+  });
+}
@@ -27,6 +27,7 @@ import {
  makeStyles,
  Paper,
  Theme,
+  Typography,
 } from '@material-ui/core';
 import { Alert } from '@material-ui/lab';
 import React from 'react';
@@ -38,6 +39,7 @@ import DeveloperBoardIcon from '@material-ui/icons/DeveloperBoard';
 import { BackstageLogoIcon } from './BackstageLogoIcon';
 import FileCopyIcon from '@material-ui/icons/FileCopy';
 import { DevToolsInfo } from '@backstage/plugin-devtools-common';
+import { useSignalsApi } from '@backstage/plugin-signals-react';

 const useStyles = makeStyles((theme: Theme) =>
  createStyles({
@@ -73,6 +75,12 @@ const copyToClipboard = ({ about }: { about: DevToolsInfo | undefined }) => {
 export const InfoContent = () => {
  const classes = useStyles();
  const { about, loading, error } = useInfo();
+  // Just testing for signals
+  const [messages, setMessages] = React.useState<string[]>([]);
+  useSignalsApi(message => {
+    messages.push(JSON.stringify(message));
+    setMessages([...messages]);
+  });

  if (loading) {
    return <Progress />;
@@ -81,6 +89,11 @@ export const InfoContent = () => {
  }
  return (
    <Box>
+      <Paper>
+        {messages.map((msg, i) => {
+          return <Typography key={i}>{msg}</Typography>;
+        })}
+      </Paper>
      <Paper className={classes.paperStyle}>
        <List className={classes.flexContainer}>
          <ListItem>
@@ -0,0 +1 @@
+module.exports = require('@backstage/cli/config/eslint-factory')(__dirname);
@@ -0,0 +1,31 @@
+# signals
+
+Welcome to the signals backend plugin!
+
+Signals plugin allows backend plugins to publish messages to frontend plugins.
+
+## Getting started
+
+Add Signals router to your backend in `packages/backend/src/plugins/signals.ts`:
+
+```ts
+import { Router } from 'express';
+import { createRouter } from '@backstage/plugin-signals-backend';
+import { SignalsService } from '@backstage/plugin-signals-node';
+import { PluginEnvironment } from '../types';
+
+export default async function createPlugin(
+  env: PluginEnvironment,
+): Promise<Router> {
+  const service = SignalsService.create({
+    logger: env.logger,
+    identity: env.identity,
+    eventBroker: env.eventBroker,
+  });
+
+  return await createRouter({
+    logger: env.logger,
+    service,
+  });
+}
+```
@@ -0,0 +1,22 @@
+## API Report File for "@backstage/plugin-signals-backend"
+
+> Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
+
+```ts
+import express from 'express';
+import { Logger } from 'winston';
+import { SignalsService } from '@backstage/plugin-signals-node';
+
+// @public (undocumented)
+export function createRouter(options: RouterOptions): Promise<express.Router>;
+
+// @public (undocumented)
+export interface RouterOptions {
+  // (undocumented)
+  logger: Logger;
+  // (undocumented)
+  service: SignalsService;
+}
+
+// (No @packageDocumentation comment for this package)
+```
@@ -0,0 +1,9 @@
+apiVersion: backstage.io/v1alpha1
+kind: Component
+metadata:
+  name: backstage-plugin-signals-backend
+  title: '@backstage/plugin-signals-backend'
+spec:
+  lifecycle: experimental
+  type: backstage-backend-plugin
+  owner: maintainers
@@ -0,0 +1,50 @@
+{
+  "name": "@backstage/plugin-signals-backend",
+  "version": "0.0.0",
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "license": "Apache-2.0",
+  "publishConfig": {
+    "access": "public",
+    "main": "dist/index.cjs.js",
+    "types": "dist/index.d.ts"
+  },
+  "backstage": {
+    "role": "backend-plugin"
+  },
+  "scripts": {
+    "start": "backstage-cli package start",
+    "build": "backstage-cli package build",
+    "lint": "backstage-cli package lint",
+    "test": "backstage-cli package test",
+    "clean": "backstage-cli package clean",
+    "prepack": "backstage-cli package prepack",
+    "postpack": "backstage-cli package postpack"
+  },
+  "dependencies": {
+    "@backstage/backend-common": "workspace:^",
+    "@backstage/config": "workspace:^",
+    "@backstage/plugin-auth-node": "workspace:^",
+    "@backstage/plugin-events-node": "workspace:^",
+    "@backstage/plugin-signals-node": "workspace:^",
+    "@backstage/types": "workspace:^",
+    "@types/express": "*",
+    "express": "^4.17.1",
+    "express-promise-router": "^4.1.0",
+    "http-proxy-middleware": "^2.0.0",
+    "node-fetch": "^2.6.7",
+    "uuid": "^8.0.0",
+    "winston": "^3.2.1",
+    "ws": "^8.14.2",
+    "yn": "^4.0.0"
+  },
+  "devDependencies": {
+    "@backstage/cli": "workspace:^",
+    "@types/supertest": "^2.0.8",
+    "msw": "^1.0.0",
+    "supertest": "^6.2.4"
+  },
+  "files": [
+    "dist"
+  ]
+}
@@ -0,0 +1,16 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+export * from './service/router';
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { getRootLogger } from '@backstage/backend-common';
+import yn from 'yn';
+import { startStandaloneServer } from './service/standaloneServer';
+
+const port = process.env.PLUGIN_PORT ? Number(process.env.PLUGIN_PORT) : 7007;
+const enableCors = yn(process.env.PLUGIN_CORS, { default: false });
+const logger = getRootLogger();
+
+startStandaloneServer({ port, enableCors, logger }).catch(err => {
+  logger.error(err);
+  process.exit(1);
+});
+
+process.on('SIGINT', () => {
+  logger.info('CTRL+C pressed; exiting.');
+  process.exit(0);
+});
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { getVoidLogger } from '@backstage/backend-common';
+import express from 'express';
+import request from 'supertest';
+
+import { createRouter } from './router';
+import { SignalsService } from '@backstage/plugin-signals-node';
+
+const signalsServiceMock: jest.Mocked<SignalsService> = {} as any;
+
+describe('createRouter', () => {
+  let app: express.Express;
+
+  beforeAll(async () => {
+    const router = await createRouter({
+      logger: getVoidLogger(),
+      service: signalsServiceMock,
+    });
+    app = express().use(router);
+  });
+
+  beforeEach(() => {
+    jest.resetAllMocks();
+  });
+
+  describe('GET /health', () => {
+    it('returns ok', async () => {
+      const response = await request(app).get('/health');
+
+      expect(response.status).toEqual(200);
+      expect(response.body).toEqual({ status: 'ok' });
+    });
+  });
+});
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { errorHandler } from '@backstage/backend-common';
+import express from 'express';
+import Router from 'express-promise-router';
+import { Logger } from 'winston';
+import { SignalsService } from '@backstage/plugin-signals-node';
+
+/** @public */
+export interface RouterOptions {
+  logger: Logger;
+  service: SignalsService;
+}
+
+/** @public */
+export async function createRouter(
+  options: RouterOptions,
+): Promise<express.Router> {
+  const { logger, service } = options;
+
+  const router = Router();
+  router.use(express.json());
+
+  router.get('/health', (_, response) => {
+    logger.info('PONG!');
+    response.json({ status: 'ok' });
+  });
+
+  router.get('/', async (req, _, next) => {
+    if (
+      !req.headers ||
+      req.headers.upgrade === undefined ||
+      req.headers.upgrade.toLowerCase() !== 'websocket'
+    ) {
+      next();
+      return;
+    }
+
+    await service.handleUpgrade(req);
+  });
+
+  router.use(errorHandler());
+  return router;
+}
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import {
+  createServiceBuilder,
+  HostDiscovery,
+  loadBackendConfig,
+} from '@backstage/backend-common';
+import { Server } from 'http';
+import { Logger } from 'winston';
+import { createRouter } from './router';
+import { SignalsService } from '@backstage/plugin-signals-node';
+import { DefaultIdentityClient } from '@backstage/plugin-auth-node';
+
+export interface ServerOptions {
+  port: number;
+  enableCors: boolean;
+  logger: Logger;
+}
+
+export async function startStandaloneServer(
+  options: ServerOptions,
+): Promise<Server> {
+  const logger = options.logger.child({ service: 'signals-backend' });
+  logger.debug('Starting application server...');
+  const config = await loadBackendConfig({ logger, argv: process.argv });
+  const discovery = HostDiscovery.fromConfig(config);
+
+  const identity = DefaultIdentityClient.create({
+    discovery,
+    issuer: await discovery.getExternalBaseUrl('auth'),
+  });
+
+  const signals = SignalsService.create({
+    logger: logger,
+    identity,
+  });
+
+  const router = await createRouter({
+    logger,
+    service: signals,
+  });
+
+  let service = createServiceBuilder(module)
+    .setPort(options.port)
+    .addRouter('/signals', router);
+  if (options.enableCors) {
+    service = service.enableCors({ origin: 'http://localhost:3000' });
+  }
+
+  return await service.start().catch(err => {
+    logger.error(err);
+    process.exit(1);
+  });
+}
+
+module.hot?.accept();
@@ -0,0 +1,16 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+export {};
@@ -0,0 +1 @@
+module.exports = require('@backstage/cli/config/eslint-factory')(__dirname);
@@ -0,0 +1,5 @@
+# @backstage/plugin-signals-node
+
+Welcome to the Node.js library package for the signals plugin!
+
+_This plugin was created through the Backstage CLI_
@@ -0,0 +1,47 @@
+## API Report File for "@backstage/plugin-signals-node"
+
+> Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
+
+```ts
+import { EventBroker } from '@backstage/plugin-events-node';
+import { EventParams } from '@backstage/plugin-events-node';
+import { EventSubscriber } from '@backstage/plugin-events-node';
+import { IdentityApi } from '@backstage/plugin-auth-node';
+import { JsonObject } from '@backstage/types';
+import { Logger } from 'winston';
+import { Request as Request_2 } from 'express';
+
+// @public (undocumented)
+export type ServiceOptions = {
+  eventBroker?: EventBroker;
+  logger: Logger;
+  identity: IdentityApi;
+};
+
+// @public (undocumented)
+export type SignalsEventBrokerPayload = {
+  recipients?: string[];
+  topic?: string;
+  message?: JsonObject;
+};
+
+// @public (undocumented)
+export class SignalsService implements EventSubscriber {
+  // (undocumented)
+  static create(options: ServiceOptions): SignalsService;
+  // (undocumented)
+  handleUpgrade: (req: Request_2) => Promise<void>;
+  // (undocumented)
+  onEvent(params: EventParams<SignalsEventBrokerPayload>): Promise<void>;
+  // (undocumented)
+  publish(
+    to: string | string[],
+    message: JsonObject,
+    topic?: string,
+  ): Promise<void>;
+  // (undocumented)
+  supportsEventTopics(): string[];
+}
+
+// (No @packageDocumentation comment for this package)
+```
@@ -0,0 +1,10 @@
+apiVersion: backstage.io/v1alpha1
+kind: Component
+metadata:
+  name: backstage-plugin-signals-node
+  title: '@backstage/plugin-signals-node'
+  description: Node.js library for the signals plugin
+spec:
+  lifecycle: experimental
+  type: backstage-node-library
+  owner: maintainers
@@ -0,0 +1,42 @@
+{
+  "name": "@backstage/plugin-signals-node",
+  "description": "Node.js library for the signals plugin",
+  "version": "0.0.0",
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "license": "Apache-2.0",
+  "publishConfig": {
+    "access": "public",
+    "main": "dist/index.cjs.js",
+    "types": "dist/index.d.ts"
+  },
+  "backstage": {
+    "role": "node-library"
+  },
+  "scripts": {
+    "build": "backstage-cli package build",
+    "lint": "backstage-cli package lint",
+    "test": "backstage-cli package test",
+    "clean": "backstage-cli package clean",
+    "prepack": "backstage-cli package prepack",
+    "postpack": "backstage-cli package postpack"
+  },
+  "devDependencies": {
+    "@backstage/cli": "workspace:^",
+    "@types/express": "^4.17.21"
+  },
+  "files": [
+    "dist"
+  ],
+  "dependencies": {
+    "@backstage/backend-common": "workspace:^",
+    "@backstage/config": "workspace:^",
+    "@backstage/plugin-auth-node": "workspace:^",
+    "@backstage/plugin-events-node": "workspace:^",
+    "@backstage/types": "workspace:^",
+    "express": "^4.17.1",
+    "uuid": "^8.0.0",
+    "winston": "^3.2.1",
+    "ws": "^8.14.2"
+  }
+}
@@ -0,0 +1,226 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import {
+  EventBroker,
+  EventParams,
+  EventSubscriber,
+} from '@backstage/plugin-events-node';
+import { Logger } from 'winston';
+import { ServiceOptions, SignalConnection } from './types';
+import { RawData, WebSocket, WebSocketServer } from 'ws';
+import { IncomingMessage } from 'http';
+import { v4 as uuid } from 'uuid';
+import { Request } from 'express';
+import { JsonObject } from '@backstage/types';
+import {
+  BackstageIdentityResponse,
+  IdentityApi,
+} from '@backstage/plugin-auth-node';
+
+/** @public */
+export type SignalsEventBrokerPayload = {
+  recipients?: string[];
+  topic?: string;
+  message?: JsonObject;
+};
+
+/** @public */
+export class SignalsService implements EventSubscriber {
+  private readonly serverId: string;
+  private connections: Map<string, SignalConnection> = new Map<
+    string,
+    SignalConnection
+  >();
+  private eventBroker?: EventBroker;
+  private logger: Logger;
+  private identity: IdentityApi;
+  private server: WebSocketServer;
+
+  static create(options: ServiceOptions) {
+    return new SignalsService(options);
+  }
+
+  private constructor(options: ServiceOptions) {
+    ({
+      eventBroker: this.eventBroker,
+      logger: this.logger,
+      identity: this.identity,
+    } = options);
+
+    this.serverId = uuid();
+    this.server = new WebSocketServer({
+      noServer: true,
+    });
+
+    this.server.on('close', () => {
+      this.logger.info('Closing signals server');
+      this.connections.forEach(conn => {
+        conn.ws.close();
+      });
+      this.connections = new Map();
+    });
+
+    this.eventBroker?.subscribe(this);
+  }
+
+  handleUpgrade = async (req: Request) => {
+    const identity = await this.identity.getIdentity({
+      request: req,
+    });
+
+    this.server.handleUpgrade(
+      req,
+      req.socket,
+      Buffer.from(''),
+      (ws: WebSocket, __: IncomingMessage) => {
+        this.addConnection(ws, identity);
+      },
+    );
+  };
+
+  private addConnection(ws: WebSocket, identity?: BackstageIdentityResponse) {
+    const id = uuid();
+
+    const conn = {
+      id,
+      user: identity?.identity.userEntityRef ?? 'user:default/guest',
+      ws,
+      ownershipEntityRefs: identity?.identity.ownershipEntityRefs ?? [],
+      subscriptions: new Set<string>(),
+    };
+
+    this.connections.set(id, conn);
+
+    ws.on('error', (err: Error) => {
+      this.logger.info(
+        `Error occurred with connection ${id}: ${err}, closing connection`,
+      );
+      ws.close();
+      this.connections.delete(id);
+    });
+
+    ws.on('close', (code: number, reason: Buffer) => {
+      this.logger.info(
+        `Connection ${id} closed with code ${code}, reason: ${reason}`,
+      );
+      this.connections.delete(id);
+    });
+
+    ws.on('ping', () => {
+      this.logger.debug(`Ping from connection ${id}`);
+      ws.pong();
+    });
+
+    ws.on('message', (data: RawData, isBinary: boolean) => {
+      this.logger.debug(`Received message from connection ${id}: ${data}`);
+      if (isBinary) {
+        return;
+      }
+
+      try {
+        const json = JSON.parse(data.toString()) as JsonObject;
+        this.handleMessage(conn, json);
+      } catch (err: any) {
+        this.logger.error(
+          `Invalid message received from connection ${id}: ${err}`,
+        );
+      }
+    });
+  }
+
+  private handleMessage(connection: SignalConnection, message: JsonObject) {
+    if (message.action === 'subscribe' && message.topic) {
+      this.logger.info(
+        `Connection ${connection.id} subscribed to ${message.topic}`,
+      );
+      connection.subscriptions.add(message.topic as string);
+    }
+
+    if (message.action === 'unsubscribe' && message.topic) {
+      this.logger.info(
+        `Connection ${connection.id} unsubscribed from ${message.topic}`,
+      );
+      connection.subscriptions.delete(message.topic as string);
+    }
+  }
+
+  async publish(to: string | string[], message: JsonObject, topic?: string) {
+    await this.publishInternal(
+      Array.isArray(to) ? to : [to],
+      message,
+      false,
+      topic,
+    );
+  }
+
+  private async publishInternal(
+    recipients: string[],
+    message: JsonObject,
+    brokedEvent: boolean,
+    topic?: string,
+  ) {
+    this.connections.forEach(conn => {
+      if (topic && !conn.subscriptions.has(topic)) {
+        return;
+      }
+      // Sending to all users can be done with '*'
+      if (
+        !recipients.includes('*') &&
+        !conn.ownershipEntityRefs.some(ref => recipients.includes(ref))
+      ) {
+        return;
+      }
+      conn.ws.send(JSON.stringify({ topic, message }));
+    });
+
+    // If this event has not been broadcasted to all servers, then use
+    // EventBroker to do that
+    if (this.eventBroker && !brokedEvent) {
+      await this.eventBroker.publish({
+        topic: 'signals',
+        eventPayload: {
+          recipients,
+          message,
+          topic,
+        },
+        metadata: { server: this.serverId },
+      });
+    }
+  }
+
+  async onEvent(params: EventParams<SignalsEventBrokerPayload>): Promise<void> {
+    const { eventPayload, metadata } = params;
+    // Discard message from same server to prevent duplicate messages
+    if (!metadata?.server || metadata.server === this.serverId) {
+      return;
+    }
+
+    if (!eventPayload?.recipients || !eventPayload.message) {
+      return;
+    }
+
+    await this.publishInternal(
+      eventPayload.recipients,
+      eventPayload.message,
+      true,
+      eventPayload.topic,
+    );
+  }
+
+  supportsEventTopics(): string[] {
+    return ['signals'];
+  }
+}
@@ -0,0 +1,18 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export * from './SignalsService';
+export * from './types';
@@ -0,0 +1,16 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+export {};
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { IdentityApi } from '@backstage/plugin-auth-node';
+import { EventBroker } from '@backstage/plugin-events-node';
+import { Logger } from 'winston';
+import { WebSocket } from 'ws';
+
+/**
+ * @public
+ */
+export type ServiceOptions = {
+  eventBroker?: EventBroker;
+  logger: Logger;
+  identity: IdentityApi;
+};
+
+/**
+ * @internal
+ */
+export type SignalConnection = {
+  id: string;
+  user: string;
+  ws: WebSocket;
+  ownershipEntityRefs: string[];
+  subscriptions: Set<string>;
+};
@@ -0,0 +1 @@
+module.exports = require('@backstage/cli/config/eslint-factory')(__dirname);
@@ -0,0 +1,5 @@
+# @backstage/plugin-signals-react
+
+Welcome to the web library package for the signals plugin!
+
+_This plugin was created through the Backstage CLI_
@@ -0,0 +1,45 @@
+## API Report File for "@backstage/plugin-signals-react"
+
+> Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
+
+```ts
+import { ApiRef } from '@backstage/core-plugin-api';
+import { DiscoveryApi } from '@backstage/core-plugin-api';
+import { JSONObject } from '@apollo/explorer/src/helpers/types';
+import { JsonObject } from '@backstage/types';
+
+// @public (undocumented)
+export type SignalsApi = {
+  subscribe(
+    onMessage: (message: JsonObject, topic?: string) => void,
+    topic?: string,
+  ): void;
+  unsubscribe(topic?: string): void;
+};
+
+// @public (undocumented)
+export const signalsApiRef: ApiRef<SignalsApi>;
+
+// @public (undocumented)
+export class SignalsClient implements SignalsApi {
+  // (undocumented)
+  static create(options: { discoveryApi: DiscoveryApi }): SignalsClient;
+  // (undocumented)
+  static instance: SignalsClient | null;
+  // (undocumented)
+  subscribe(
+    onMessage: (message: JsonObject, topic?: string) => void,
+    topic?: string,
+  ): void;
+  // (undocumented)
+  unsubscribe(topic?: string): void;
+}
+
+// @public (undocumented)
+export const useSignalsApi: (
+  onMessage: (message: JSONObject) => void,
+  topic?: string,
+) => void;
+
+// (No @packageDocumentation comment for this package)
+```
@@ -0,0 +1,10 @@
+apiVersion: backstage.io/v1alpha1
+kind: Component
+metadata:
+  name: backstage-plugin-signals-react
+  title: '@backstage/plugin-signals-react'
+  description: Web library for the signals plugin
+spec:
+  lifecycle: experimental
+  type: backstage-web-library
+  owner: maintainers
@@ -0,0 +1,43 @@
+{
+  "name": "@backstage/plugin-signals-react",
+  "description": "Web library for the signals plugin",
+  "version": "0.0.0",
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "license": "Apache-2.0",
+  "publishConfig": {
+    "access": "public",
+    "main": "dist/index.esm.js",
+    "types": "dist/index.d.ts"
+  },
+  "backstage": {
+    "role": "web-library"
+  },
+  "sideEffects": false,
+  "scripts": {
+    "start": "backstage-cli package start",
+    "build": "backstage-cli package build",
+    "lint": "backstage-cli package lint",
+    "test": "backstage-cli package test",
+    "clean": "backstage-cli package clean",
+    "prepack": "backstage-cli package prepack",
+    "postpack": "backstage-cli package postpack"
+  },
+  "dependencies": {
+    "@backstage/core-plugin-api": "workspace:^",
+    "@backstage/types": "workspace:^",
+    "@material-ui/core": "^4.9.13"
+  },
+  "peerDependencies": {
+    "react": "^16.13.1 || ^17.0.0"
+  },
+  "devDependencies": {
+    "@backstage/cli": "workspace:^",
+    "@backstage/test-utils": "workspace:^",
+    "@testing-library/jest-dom": "^5.10.1",
+    "@testing-library/react": "^12.1.3"
+  },
+  "files": [
+    "dist"
+  ]
+}
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { createApiRef } from '@backstage/core-plugin-api';
+import { JsonObject } from '@backstage/types';
+
+/** @public */
+export const signalsApiRef = createApiRef<SignalsApi>({
+  id: 'plugin.signals.service',
+});
+
+/** @public */
+export type SignalsApi = {
+  subscribe(
+    onMessage: (message: JsonObject, topic?: string) => void,
+    topic?: string,
+  ): void;
+
+  unsubscribe(topic?: string): void;
+};
@@ -0,0 +1,133 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { SignalsApi } from './SignalsApi';
+import { JsonObject } from '@backstage/types';
+import { DiscoveryApi } from '@backstage/core-plugin-api';
+
+/** @public */
+export class SignalsClient implements SignalsApi {
+  static instance: SignalsClient | null = null;
+  private ws: WebSocket | null = null;
+  private discoveryApi: DiscoveryApi;
+  private cbs: Map<string, (message: JsonObject, topic?: string) => void> =
+    new Map();
+  private queue: JsonObject[] = [];
+  private reconnectTimeout: any;
+
+  static create(options: { discoveryApi: DiscoveryApi }) {
+    if (!SignalsClient.instance) {
+      SignalsClient.instance = new SignalsClient(options);
+    }
+    return SignalsClient.instance;
+  }
+
+  private constructor(options: { discoveryApi: DiscoveryApi }) {
+    this.discoveryApi = options.discoveryApi;
+  }
+
+  subscribe(
+    onMessage: (message: JsonObject, topic?: string) => void,
+    topic?: string,
+  ): void {
+    const subscriptionTopic = topic ?? '*';
+    // Do not allow to subscribe to same topic multiple times
+    if (this.cbs.has(subscriptionTopic)) {
+      return;
+    }
+
+    this.cbs.set(subscriptionTopic, onMessage);
+    this.connect().then(() => {
+      this.send({ action: 'subscribe', topic });
+    });
+  }
+
+  unsubscribe(topic?: string): void {
+    const subscriptionTopic = topic ?? '*';
+    this.cbs.delete(subscriptionTopic);
+    this.send({ action: 'unsubscribe', topic });
+  }
+
+  private send(data?: JsonObject): void {
+    if (!this.ws || this.ws.readyState !== WebSocket.OPEN) {
+      if (data) {
+        this.queue.push(data);
+      }
+      return;
+    }
+
+    // First send queue
+    for (const msg of this.queue) {
+      this.ws!.send(JSON.stringify(msg));
+    }
+    this.queue = [];
+    if (data) {
+      this.ws!.send(JSON.stringify(data));
+    }
+  }
+
+  private async connect() {
+    if (this.ws) {
+      return;
+    }
+
+    const apiUrl = `${await this.discoveryApi.getBaseUrl('signals')}`;
+    const url = new URL(apiUrl);
+    url.protocol = url.protocol === 'http:' ? 'ws' : 'wss';
+    this.ws = new WebSocket(url.toString());
+
+    this.ws.onmessage = (data: MessageEvent) => {
+      try {
+        const json = JSON.parse(data.data) as JsonObject;
+        let cb = this.cbs.get('*');
+        if (json.topic) {
+          cb = this.cbs.get(json.topic as string);
+        }
+        if (cb) {
+          cb(json.message as JsonObject, json.topic as string);
+        }
+      } catch (e) {
+        // NOOP
+      }
+    };
+
+    this.ws.onerror = () => {
+      this.reconnect();
+    };
+
+    this.ws.onclose = () => {
+      this.reconnect();
+    };
+
+    while (this.ws.readyState !== WebSocket.OPEN) {
+      await new Promise(r => setTimeout(r, 10));
+    }
+    this.send();
+  }
+
+  private reconnect() {
+    if (this.reconnectTimeout) {
+      clearTimeout(this.reconnectTimeout);
+    }
+
+    this.reconnectTimeout = setTimeout(() => {
+      if (this.ws) {
+        this.ws.close();
+      }
+      this.ws = null;
+      this.connect();
+    }, 5000);
+  }
+}
@@ -0,0 +1,17 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+export * from './SignalsApi';
+export * from './SignalsClient';
@@ -0,0 +1,16 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+export * from './useSignalsApi';
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { SignalsClient } from '../api';
+import { discoveryApiRef, useApi } from '@backstage/core-plugin-api';
+import { JSONObject } from '@apollo/explorer/src/helpers/types';
+import { useEffect } from 'react';
+
+/** @public */
+export const useSignalsApi = (
+  onMessage: (message: JSONObject) => void,
+  topic?: string,
+) => {
+  const discovery = useApi(discoveryApiRef);
+  const signals = SignalsClient.create({ discoveryApi: discovery });
+  useEffect(() => {
+    signals.subscribe(onMessage, topic);
+  }, [signals, onMessage, topic]);
+
+  useEffect(() => {
+    return () => {
+      signals.unsubscribe(topic);
+    };
+  }, [signals, topic]);
+};
@@ -0,0 +1,18 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export * from './api';
+export * from './hooks';
@@ -0,0 +1,16 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import '@testing-library/jest-dom';
@@ -12,7 +12,7 @@ __metadata:
  languageName: node
  linkType: hard

-"@adobe/css-tools@npm:^4.3.2":
+"@adobe/css-tools@npm:^4.0.1, @adobe/css-tools@npm:^4.3.2":
  version: 4.3.2
  resolution: "@adobe/css-tools@npm:4.3.2"
  checksum: 9667d61d55dc3b0a315c530ae84e016ce5267c4dd8ac00abb40108dc98e07b98e3090ce8b87acd51a41a68d9e84dcccb08cdf21c902572a9cf9dcaf830da4ae3
@@ -8833,6 +8833,66 @@ __metadata:
  languageName: unknown
  linkType: soft

+"@backstage/plugin-signals-backend@workspace:^, @backstage/plugin-signals-backend@workspace:plugins/signals-backend":
+  version: 0.0.0-use.local
+  resolution: "@backstage/plugin-signals-backend@workspace:plugins/signals-backend"
+  dependencies:
+    "@backstage/backend-common": "workspace:^"
+    "@backstage/cli": "workspace:^"
+    "@backstage/config": "workspace:^"
+    "@backstage/plugin-auth-node": "workspace:^"
+    "@backstage/plugin-events-node": "workspace:^"
+    "@backstage/plugin-signals-node": "workspace:^"
+    "@backstage/types": "workspace:^"
+    "@types/express": "*"
+    "@types/supertest": ^2.0.8
+    express: ^4.17.1
+    express-promise-router: ^4.1.0
+    http-proxy-middleware: ^2.0.0
+    msw: ^1.0.0
+    node-fetch: ^2.6.7
+    supertest: ^6.2.4
+    uuid: ^8.0.0
+    winston: ^3.2.1
+    ws: ^8.14.2
+    yn: ^4.0.0
+  languageName: unknown
+  linkType: soft
+
+"@backstage/plugin-signals-node@workspace:^, @backstage/plugin-signals-node@workspace:plugins/signals-node":
+  version: 0.0.0-use.local
+  resolution: "@backstage/plugin-signals-node@workspace:plugins/signals-node"
+  dependencies:
+    "@backstage/backend-common": "workspace:^"
+    "@backstage/cli": "workspace:^"
+    "@backstage/config": "workspace:^"
+    "@backstage/plugin-auth-node": "workspace:^"
+    "@backstage/plugin-events-node": "workspace:^"
+    "@backstage/types": "workspace:^"
+    "@types/express": ^4.17.21
+    express: ^4.17.1
+    uuid: ^8.0.0
+    winston: ^3.2.1
+    ws: ^8.14.2
+  languageName: unknown
+  linkType: soft
+
+"@backstage/plugin-signals-react@workspace:plugins/signals-react":
+  version: 0.0.0-use.local
+  resolution: "@backstage/plugin-signals-react@workspace:plugins/signals-react"
+  dependencies:
+    "@backstage/cli": "workspace:^"
+    "@backstage/core-plugin-api": "workspace:^"
+    "@backstage/test-utils": "workspace:^"
+    "@backstage/types": "workspace:^"
+    "@material-ui/core": ^4.9.13
+    "@testing-library/jest-dom": ^5.10.1
+    "@testing-library/react": ^12.1.3
+  peerDependencies:
+    react: ^16.13.1 || ^17.0.0
+  languageName: unknown
+  linkType: soft
+
 "@backstage/plugin-sonarqube-backend@workspace:^, @backstage/plugin-sonarqube-backend@workspace:plugins/sonarqube-backend":
  version: 0.0.0-use.local
  resolution: "@backstage/plugin-sonarqube-backend@workspace:plugins/sonarqube-backend"
@@ -17125,6 +17185,22 @@ __metadata:
  languageName: unknown
  linkType: soft

+"@testing-library/dom@npm:^8.0.0":
+  version: 8.20.1
+  resolution: "@testing-library/dom@npm:8.20.1"
+  dependencies:
+    "@babel/code-frame": ^7.10.4
+    "@babel/runtime": ^7.12.5
+    "@types/aria-query": ^5.0.1
+    aria-query: 5.1.3
+    chalk: ^4.1.0
+    dom-accessibility-api: ^0.5.9
+    lz-string: ^1.5.0
+    pretty-format: ^27.0.2
+  checksum: 06fc8dc67849aadb726cbbad0e7546afdf8923bd39acb64c576d706249bd7d0d05f08e08a31913fb621162e3b9c2bd0dce15964437f030f9fa4476326fdd3007
+  languageName: node
+  linkType: hard
+
 "@testing-library/dom@npm:^9.0.0":
  version: 9.3.3
  resolution: "@testing-library/dom@npm:9.3.3"
@@ -17141,6 +17217,23 @@ __metadata:
  languageName: node
  linkType: hard

+"@testing-library/jest-dom@npm:^5.10.1":
+  version: 5.17.0
+  resolution: "@testing-library/jest-dom@npm:5.17.0"
+  dependencies:
+    "@adobe/css-tools": ^4.0.1
+    "@babel/runtime": ^7.9.2
+    "@types/testing-library__jest-dom": ^5.9.1
+    aria-query: ^5.0.0
+    chalk: ^3.0.0
+    css.escape: ^1.5.1
+    dom-accessibility-api: ^0.5.6
+    lodash: ^4.17.15
+    redent: ^3.0.0
+  checksum: 9f28dbca8b50d7c306aae40c3aa8e06f0e115f740360004bd87d57f95acf7ab4b4f4122a7399a76dbf2bdaaafb15c99cc137fdcb0ae457a92e2de0f3fbf9b03b
+  languageName: node
+  linkType: hard
+
 "@testing-library/jest-dom@npm:^6.0.0":
  version: 6.1.6
  resolution: "@testing-library/jest-dom@npm:6.1.6"
@@ -17193,6 +17286,20 @@ __metadata:
  languageName: node
  linkType: hard

+"@testing-library/react@npm:^12.1.3":
+  version: 12.1.5
+  resolution: "@testing-library/react@npm:12.1.5"
+  dependencies:
+    "@babel/runtime": ^7.12.5
+    "@testing-library/dom": ^8.0.0
+    "@types/react-dom": <18.0.0
+  peerDependencies:
+    react: <18.0.0
+    react-dom: <18.0.0
+  checksum: 4abd0490405e709a7df584a0db604e508a4612398bb1326e8fa32dd9393b15badc826dcf6d2f7525437886d507871f719f127b9860ed69ddd204d1fa834f576a
+  languageName: node
+  linkType: hard
+
 "@testing-library/react@npm:^14.0.0":
  version: 14.1.2
  resolution: "@testing-library/react@npm:14.1.2"
@@ -17884,7 +17991,7 @@ __metadata:
  languageName: node
  linkType: hard

-"@types/express@npm:*, @types/express@npm:^4.17.13, @types/express@npm:^4.17.17, @types/express@npm:^4.17.6":
+"@types/express@npm:*, @types/express@npm:^4.17.13, @types/express@npm:^4.17.17, @types/express@npm:^4.17.21, @types/express@npm:^4.17.6":
  version: 4.17.21
  resolution: "@types/express@npm:4.17.21"
  dependencies:
@@ -26588,6 +26695,8 @@ __metadata:
    "@backstage/plugin-search-backend-module-techdocs": "workspace:^"
    "@backstage/plugin-search-backend-node": "workspace:^"
    "@backstage/plugin-search-common": "workspace:^"
+    "@backstage/plugin-signals-backend": "workspace:^"
+    "@backstage/plugin-signals-node": "workspace:^"
    "@backstage/plugin-tech-insights-backend": "workspace:^"
    "@backstage/plugin-tech-insights-backend-module-jsonfc": "workspace:^"
    "@backstage/plugin-tech-insights-node": "workspace:^"
@@ -44545,7 +44654,7 @@ __metadata:
  languageName: node
  linkType: hard

-"ws@npm:*, ws@npm:8.14.2, ws@npm:^8.11.0, ws@npm:^8.12.0, ws@npm:^8.13.0, ws@npm:^8.8.0":
+"ws@npm:*, ws@npm:8.14.2, ws@npm:^8.11.0, ws@npm:^8.12.0, ws@npm:^8.13.0, ws@npm:^8.14.2, ws@npm:^8.8.0":
  version: 8.14.2
  resolution: "ws@npm:8.14.2"
  peerDependencies:
				`@@ -0,0 +1 @@`
				`module.exports = require('@backstage/cli/config/eslint-factory')(__dirname);`