refactor(core): Remove sse-channel (no-changelog) (#11207)

packages/cli/package.json

@@ -163,7 +163,6 @@
     "simple-git": "3.17.0",
     "source-map-support": "0.5.21",
     "sqlite3": "5.1.7",
-    "sse-channel": "4.0.0",
     "sshpk": "1.17.0",
     "swagger-ui-express": "5.0.1",
     "syslog-client": "1.1.1",

packages/cli/src/push/abstract.push.ts

@@ -1,8 +1,9 @@
 import type { PushPayload, PushType } from '@n8n/api-types';
 import { assert, jsonStringify } from 'n8n-workflow';
+import { Service } from 'typedi';
 
 import type { User } from '@/databases/entities/user';
-import type { Logger } from '@/logging/logger.service';
+import { Logger } from '@/logging/logger.service';
 import type { OnPushMessage } from '@/push/types';
 import { TypedEmitter } from '@/typed-emitter';
 
@@ -16,6 +17,7 @@ export interface AbstractPushEvents {
  *
  * @emits message when a message is received from a client
  */
+@Service()
 export abstract class AbstractPush<Connection> extends TypedEmitter<AbstractPushEvents> {
 	protected connections: Record<string, Connection> = {};
 
@@ -23,9 +25,12 @@ export abstract class AbstractPush<Connection> extends TypedEmitter<AbstractPush
 
 	protected abstract close(connection: Connection): void;
 	protected abstract sendToOneConnection(connection: Connection, data: string): void;
+	protected abstract ping(connection: Connection): void;
 
 	constructor(protected readonly logger: Logger) {
 		super();
+		// Ping all connected clients every 60 seconds
+		setInterval(() => this.pingAll(), 60 * 1000);
 	}
 
 	protected add(pushRef: string, userId: User['id'], connection: Connection) {
@@ -75,6 +80,12 @@ export abstract class AbstractPush<Connection> extends TypedEmitter<AbstractPush
 		}
 	}
 
+	private pingAll() {
+		for (const pushRef in this.connections) {
+			this.ping(this.connections[pushRef]);
+		}
+	}
+
 	sendToAll<Type extends PushType>(type: Type, data: PushPayload<Type>) {
 		this.sendTo(type, data, Object.keys(this.connections));
 	}

packages/cli/src/push/sse.push.ts

@@ -1,8 +1,6 @@
 import { Service } from 'typedi';
 
 import type { User } from '@/databases/entities/user';
-import { Logger } from '@/logging/logger.service';
-import SSEChannel from 'sse-channel';
 
 import { AbstractPush } from './abstract.push';
 import type { PushRequest, PushResponse } from './types';
@@ -11,29 +9,41 @@ type Connection = { req: PushRequest; res: PushResponse };
 
 @Service()
 export class SSEPush extends AbstractPush<Connection> {
-	readonly channel = new SSEChannel();
-
-	readonly connections: Record<string, Connection> = {};
-
-	constructor(logger: Logger) {
-		super(logger);
-
-		this.channel.on('disconnect', (_, { req }) => {
-			this.remove(req?.query?.pushRef);
-		});
-	}
-
 	add(pushRef: string, userId: User['id'], connection: Connection) {
+		const { req, res } = connection;
+
+		// Initialize the connection
+		req.socket.setTimeout(0);
+		req.socket.setNoDelay(true);
+		req.socket.setKeepAlive(true);
+		res.setHeader('Content-Type', 'text/event-stream; charset=UTF-8');
+		res.setHeader('Cache-Control', 'no-cache');
+		res.setHeader('Connection', 'keep-alive');
+		res.writeHead(200);
+		res.write(':ok\n\n');
+		res.flush();
+
 		super.add(pushRef, userId, connection);
-		this.channel.addClient(connection.req, connection.res);
+
+		// When the client disconnects, remove the client
+		const removeClient = () => this.remove(pushRef);
+		req.once('end', removeClient);
+		req.once('close', removeClient);
+		res.once('finish', removeClient);
 	}
 
 	protected close({ res }: Connection) {
 		res.end();
-		this.channel.removeClient(res);
 	}
 
 	protected sendToOneConnection(connection: Connection, data: string) {
-		this.channel.send(data, [connection.res]);
+		const { res } = connection;
+		res.write('data: ' + data + '\n\n');
+		res.flush();
+	}
+
+	protected ping({ res }: Connection) {
+		res.write(':ping\n\n');
+		res.flush();
 	}
 }

packages/cli/src/push/types.ts

@@ -11,7 +11,15 @@ export type PushRequest = AuthenticatedRequest<{}, {}, {}, { pushRef: string }>;
 export type SSEPushRequest = PushRequest & { ws: undefined };
 export type WebSocketPushRequest = PushRequest & { ws: WebSocket };
 
-export type PushResponse = Response & { req: PushRequest };
+export type PushResponse = Response & {
+	req: PushRequest;
+	/**
+	 * `flush()` is defined in the compression middleware.
+	 * This is necessary because the compression middleware sometimes waits
+	 * for a certain amount of data before sending the data to the client
+	 */
+	flush: () => void;
+};
 
 export interface OnPushMessage {
 	pushRef: string;

packages/cli/src/push/websocket.push.ts

@@ -3,7 +3,6 @@ import { Service } from 'typedi';
 import type WebSocket from 'ws';
 
 import type { User } from '@/databases/entities/user';
-import { Logger } from '@/logging/logger.service';
 
 import { AbstractPush } from './abstract.push';
 
@@ -13,13 +12,6 @@ function heartbeat(this: WebSocket) {
 
 @Service()
 export class WebSocketPush extends AbstractPush<WebSocket> {
-	constructor(logger: Logger) {
-		super(logger);
-
-		// Ping all connected clients every 60 seconds
-		setInterval(() => this.pingAll(), 60 * 1000);
-	}
-
 	add(pushRef: string, userId: User['id'], connection: WebSocket) {
 		connection.isAlive = true;
 		connection.on('pong', heartbeat);
@@ -67,17 +59,12 @@ export class WebSocketPush extends AbstractPush<WebSocket> {
 		connection.send(data);
 	}
 
-	private pingAll() {
-		for (const pushRef in this.connections) {
-			const connection = this.connections[pushRef];
-			// If a connection did not respond with a `PONG` in the last 60 seconds, disconnect
-			if (!connection.isAlive) {
-				delete this.connections[pushRef];
-				return connection.terminate();
-			}
-
-			connection.isAlive = false;
-			connection.ping();
+	protected ping(connection: WebSocket): void {
+		// If a connection did not respond with a `PONG` in the last 60 seconds, disconnect
+		if (!connection.isAlive) {
+			return connection.terminate();
 		}
+		connection.isAlive = false;
+		connection.ping();
 	}
 }

packages/cli/src/sse-channel.d.ts

@@ -1,17 +0,0 @@
-import type { PushRequest, PushResponse } from './push/types';
-
-declare module 'sse-channel' {
-	declare class Channel {
-		constructor();
-
-		on(event: string, handler: (channel: string, res: PushResponse) => void): void;
-
-		removeClient: (res: PushResponse) => void;
-
-		addClient: (req: PushRequest, res: PushResponse) => void;
-
-		send: (msg: string, clients?: PushResponse[]) => void;
-	}
-
-	export = Channel;
-}

pnpm-lock.yaml

@@ -937,9 +937,6 @@ importers:
       sqlite3:
         specifier: 5.1.7
         version: 5.1.7
-      sse-channel:
-        specifier: 4.0.0
-        version: 4.0.0
       sshpk:
         specifier: 1.17.0
         version: 1.17.0
@@ -11081,9 +11078,6 @@ packages:
     resolution: {integrity: sha512-qC9iz2FlN7DQl3+wjwn3802RTyjCx7sDvfQEXchwa6CWOx07/WVfh91gBmQ9fahw8snwGEWU3xGzOt4tFyHLxg==}
     engines: {node: '>= 0.6'}
 
-  sse-channel@4.0.0:
-    resolution: {integrity: sha512-I539Tc0gyDTQ2QCSg4v78Flxo/UbqR9x7JoyPcqaPtwo+qzeOw/fF+aPSbk0xTvBQAAAZk7Dlkc8K1bum5GUnw==}
-
   ssh2-sftp-client@7.2.3:
     resolution: {integrity: sha512-Bmq4Uewu3e0XOwu5bnPbiS5KRQYv+dff5H6+85V4GZrPrt0Fkt1nUH+uXanyAkoNxUpzjnAPEEoLdOaBO9c3xw==}
     engines: {node: '>=10.24.1'}
@@ -24356,8 +24350,6 @@ snapshots:
 
   sqlstring@2.3.3: {}
 
-  sse-channel@4.0.0: {}
-
   ssh2-sftp-client@7.2.3:
     dependencies:
       concat-stream: 2.0.0