amqp listener with debug-console output

packages/nodes-base/credentials/Amqp.credentials.ts

@@ -0,0 +1,30 @@
+import {
+	ICredentialType,
+	NodePropertyTypes,
+} from 'n8n-workflow';
+
+
+export class Amqp implements ICredentialType {
+	name = 'amqp';
+	displayName = 'AMQP';
+	properties = [
+		// The credentials to get from user and save encrypted.
+		// Properties can be defined exactly in the same way
+		// as node properties.
+		{
+			displayName: 'User',
+			name: 'username',
+			type: 'string' as NodePropertyTypes,
+			default: '',
+		},
+		{
+			displayName: 'Password',
+			name: 'password',
+			type: 'string' as NodePropertyTypes,
+			typeOptions: {
+				password: true,
+			},
+			default: '',
+		},
+	];
+}

packages/nodes-base/nodes/Amqp/AmqpListener.node.ts

@@ -0,0 +1,171 @@
+import { ITriggerFunctions } from 'n8n-core';
+import {
+	INodeType,
+	INodeTypeDescription,
+	ITriggerResponse,
+
+} from 'n8n-workflow';
+
+
+export class AmqpListener implements INodeType {
+	description: INodeTypeDescription = {
+		displayName: 'AMQP Listener',
+		name: 'amqpListener',
+		icon: 'file:amqp.png',
+		group: ['trigger'],
+		version: 1,
+		description: 'Listens to AMQP 1.0 Messages',
+		defaults: {
+			name: 'AMQP Listener',
+			color: '#00FF00',
+		},
+		inputs: [],
+		outputs: ['main'],
+		credentials: [{
+			name: 'amqp',
+			required: false,
+		}],
+		properties: [
+			// Node properties which the user gets displayed and
+			// can change on the node.
+			{
+				displayName: 'Host',
+				name: 'hostname',
+				type: 'string',
+				default: 'localhost',
+				description: 'hostname of the amqp server',
+			},
+			{
+				displayName: 'Port',
+				name: 'port',
+				type: 'number',
+				typeOptions: {
+					minValue: 1,
+				},
+				default: 5672,
+				description: 'TCP Port to connect to',
+			},
+			{
+				displayName: 'Queue / Topic',
+				name: 'sink',
+				type: 'string',
+				default: '',
+				placeholder: 'topic://sourcename.something',
+				description: 'name of the queue of topic to listen to',
+			},
+			{
+				displayName: 'Clientname',
+				name: 'clientname',
+				type: 'string',
+				default: '',
+				placeholder: 'for durable/persistent topic subscriptions, example: "n8n"',
+				description: 'Leave empty for non-durable topic subscriptions or queues. ',
+			},
+			{
+				displayName: 'Subscription',
+				name: 'subscription',
+				type: 'string',
+				default: '',
+				placeholder: 'for durable/persistent topic subscriptions, example: "order-worker"',
+				description: 'Leave empty for non-durable topic subscriptions or queues',
+			},
+		]
+	};
+
+
+	async trigger(this: ITriggerFunctions): Promise<ITriggerResponse> {
+
+		const credentials = this.getCredentials('amqp');
+
+		const hostname = this.getNodeParameter('hostname', 'localhost') as string;
+		const port = this.getNodeParameter('port', 5672) as number;
+		const sink = this.getNodeParameter('sink', '') as string;
+		const clientname = this.getNodeParameter('clientname', '') as string;
+		const subscription = this.getNodeParameter('subscription', '') as string;
+
+		if (sink == '') {
+			throw new Error('Queue or Topic required!');
+		}
+		let durable: boolean = false;
+		if(subscription && clientname) {
+			console.log('durable subscription')
+			durable = true;
+		}
+
+		let container = require('rhea');
+		let connectOptions = {
+			host: hostname,
+			port: port,
+			reconnect: true,		// this id the default anyway
+			reconnect_limit: 50,	// try for max 50 times, based on a back-off algorithm
+			container_id: (durable ? clientname : null)
+		}
+		if (credentials) {
+			container.options.username = credentials.username;
+			container.options.password = credentials.password;
+		}
+
+		let lastMsgId: any = undefined;
+		let self = this;
+
+		container.on('message', function (context: any) {
+			console.log('AMQP: received message id: ' + (context.message.message_id ? context.message.message_id : ''));
+			console.log(context.message.body);
+			if (context.message.message_id && context.message.message_id == lastMsgId) {
+				// ignore duplicate message check, don't think it's necessary, but it was in the rhea-lib example code
+				console.log('duplicate received: ' + context.message.message_id);
+				lastMsgId = context.message.message_id;
+				return;
+			}
+			self.emit([self.helpers.returnJsonArray([context.message])]);
+		});
+		
+		let connection = container.connect(connectOptions);
+		let clientOptions = undefined;
+		if (durable) {
+			clientOptions = {
+				name: subscription,
+				source: {
+					address: sink,
+					durable: 2,
+					expiry_policy: 'never'
+				},
+				credit_window: 1	// prefetch 1
+			}
+		} else {
+			clientOptions = {
+				source: {
+					address: sink,
+				},
+				credit_window: 1	// prefetch 1
+			}
+		}
+		connection.open_receiver(clientOptions);
+		console.log('AMQP: listener attached');
+
+
+		// The "closeFunction" function gets called by n8n whenever
+		// the workflow gets deactivated and can so clean up.
+		async function closeFunction() {
+			connection.close();
+			console.log('AMQP: listener closed');
+		}
+
+		// The "manualTriggerFunction" function gets called by n8n
+		// when a user is in the workflow editor and starts the
+		// workflow manually.
+		// does not make really sense for AMQP
+		async function manualTriggerFunction() {
+			console.log('AMQP: manual trigger clicked, this will make the node spinn, until a message is received on: ' + sink);
+/*			self.emit([self.helpers.returnJsonArray([{
+				error: '"manually triggered execution" stops the node right afterwards which unsubscribes the listener from the service bus. You need to activate the workflow to test.'
+			}])]); */
+		}
+
+		return {
+			closeFunction,
+			manualTriggerFunction,
+		};
+
+	}
+}

packages/nodes-base/package.json

@@ -28,6 +28,7 @@
         "credentials": [
             "dist/credentials/ActiveCampaignApi.credentials.js",
             "dist/credentials/AirtableApi.credentials.js",
+            "dist/credentials/Amqp.credentials.js",
             "dist/credentials/AsanaApi.credentials.js",
             "dist/credentials/Aws.credentials.js",
             "dist/credentials/ChargebeeApi.credentials.js",
@@ -59,6 +60,7 @@
         "nodes": [
             "dist/nodes/ActiveCampaign/ActiveCampaign.node.js",
             "dist/nodes/Airtable/Airtable.node.js",
+            "dist/nodes/Amqp/AmqpListener.node.js",
             "dist/nodes/Asana/Asana.node.js",
             "dist/nodes/Asana/AsanaTrigger.node.js",
             "dist/nodes/Aws/AwsLambda.node.js",
@@ -158,6 +160,7 @@
         "pdf-parse": "^1.1.1",
         "pg-promise": "^9.0.3",
         "redis": "^2.8.0",
+        "rhea": "^1.0.11",
         "rss-parser": "^3.7.0",
         "vm2": "^3.6.10",
         "xlsx": "^0.14.3",