✨ Add RabbitMQ and RabbitMQ Trigger Node (#1258)

* ✨ Add RabbitMQ-Node

* ✨ Add RabbitMQ-Trigger Node

* ⚡ Fix issue that connection errors did not get caught

* 🔨Fix name and description for RabbitMQ Trigger node

Co-authored-by: Harshil <ghagrawal17@gmail.com>

packages/nodes-base/nodes/RabbitMQ/GenericFunctions.ts

@@ -0,0 +1,62 @@
+import {
+	IDataObject,
+	IExecuteFunctions,
+	ITriggerFunctions,
+} from 'n8n-workflow';
+
+const amqplib = require('amqplib');
+
+export async function rabbitmqConnect(this: IExecuteFunctions | ITriggerFunctions, queue: string, options: IDataObject): Promise<any> { // tslint:disable-line:no-any
+	const credentials = this.getCredentials('rabbitmq') as IDataObject;
+
+	const credentialKeys = [
+		'hostname',
+		'port',
+		'username',
+		'password',
+		'vhost',
+	];
+	const credentialData: IDataObject = {};
+	credentialKeys.forEach(key => {
+		credentialData[key] = credentials[key] === '' ? undefined : credentials[key];
+	});
+
+	const optsData: IDataObject = {};
+	if (credentials.ssl === true) {
+		credentialData.protocol = 'amqps';
+
+		optsData.cert = credentials.cert === '' ? undefined : Buffer.from(credentials.cert as string);
+		optsData.key = credentials.key === '' ? undefined : Buffer.from(credentials.key as string);
+		optsData.passphrase = credentials.passphrase === '' ? undefined : credentials.passphrase;
+		optsData.ca = credentials.ca === '' ? undefined : [Buffer.from(credentials.ca as string)];
+		optsData.credentials = amqplib.credentials.external();
+	}
+
+
+	return new Promise(async (resolve, reject) => {
+		try {
+			const connection = await amqplib.connect(credentialData, optsData);
+
+			connection.on('error', (error: Error) => {
+				reject(error);
+			});
+
+			const channel = await connection.createChannel().catch(console.warn);
+
+			if (options.arguments && ((options.arguments as IDataObject).argument! as IDataObject[]).length) {
+				const additionalArguments: IDataObject = {};
+				((options.arguments as IDataObject).argument as IDataObject[]).forEach((argument: IDataObject) => {
+					additionalArguments[argument.key as string] = argument.value;
+				});
+				options.arguments = additionalArguments;
+			}
+
+			await channel.assertQueue(queue, options);
+
+			resolve(channel);
+		} catch (error) {
+			reject(error);
+		}
+	});
+
+}