mirror of
https://github.com/n8n-io/n8n.git
synced 2024-11-10 14:44:05 -08:00
296 lines
9 KiB
TypeScript
296 lines
9 KiB
TypeScript
import { Container, ContainerOptions, EventContext, Message, ReceiverOptions } from 'rhea';
|
|
|
|
import { ITriggerFunctions } from 'n8n-core';
|
|
import {
|
|
IDataObject,
|
|
INodeType,
|
|
INodeTypeDescription,
|
|
ITriggerResponse,
|
|
} from 'n8n-workflow';
|
|
|
|
|
|
export class AmqpTrigger implements INodeType {
|
|
description: INodeTypeDescription = {
|
|
displayName: 'AMQP Trigger',
|
|
name: 'amqpTrigger',
|
|
icon: 'file:amqp.png',
|
|
group: ['trigger'],
|
|
version: 1,
|
|
description: 'Listens to AMQP 1.0 Messages',
|
|
defaults: {
|
|
name: 'AMQP Trigger',
|
|
color: '#00FF00',
|
|
},
|
|
inputs: [],
|
|
outputs: ['main'],
|
|
credentials: [{
|
|
name: 'amqp',
|
|
required: true,
|
|
}],
|
|
properties: [
|
|
// Node properties which the user gets displayed and
|
|
// can change on the node.
|
|
{
|
|
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',
|
|
},
|
|
{
|
|
displayName: 'Pull N Messages per Cicle',
|
|
name: 'pullMessagesNumber',
|
|
type: 'number',
|
|
default: 100,
|
|
description: 'Number of messages to pull from the bus for every cicle',
|
|
},
|
|
{
|
|
displayName: 'Sleep time after cicle',
|
|
name: 'sleepTime',
|
|
type: 'number',
|
|
default: 10,
|
|
description: 'Milliseconds to sleep after every cicle',
|
|
},
|
|
{
|
|
displayName: 'Options',
|
|
name: 'options',
|
|
type: 'collection',
|
|
placeholder: 'Add Option',
|
|
default: {},
|
|
options: [
|
|
{
|
|
displayName: 'Convert Body To String',
|
|
name: 'jsonConvertByteArrayToString',
|
|
type: 'boolean',
|
|
default: false,
|
|
description: 'Convert JSON Body content (["body"]["content"]) from Byte Array to string. Needed for Azure Service Bus.',
|
|
},
|
|
{
|
|
displayName: 'JSON Parse Body',
|
|
name: 'jsonParseBody',
|
|
type: 'boolean',
|
|
default: false,
|
|
description: 'Parse the body to an object.',
|
|
},
|
|
{
|
|
displayName: 'Only Body',
|
|
name: 'onlyBody',
|
|
type: 'boolean',
|
|
default: false,
|
|
description: 'Returns only the body property.',
|
|
},
|
|
{
|
|
displayName: 'Messages per Cicle',
|
|
name: 'pullMessagesNumber',
|
|
type: 'number',
|
|
default: 100,
|
|
description: 'Number of messages to pull from the bus for every cicle',
|
|
},
|
|
{
|
|
displayName: 'Sleep Time',
|
|
name: 'sleepTime',
|
|
type: 'number',
|
|
default: 10,
|
|
description: 'Milliseconds to sleep after every cicle.',
|
|
},
|
|
{
|
|
displayName: 'Container ID',
|
|
name: 'containerID',
|
|
type: 'string',
|
|
default: '',
|
|
description: 'Will be used to pass to the RHEA Backend as container_id',
|
|
},
|
|
{
|
|
displayName: 'Reconnect',
|
|
name: 'reconnect',
|
|
type: 'boolean',
|
|
default: true,
|
|
description: 'If on, the library will automatically attempt to reconnect if disconnected',
|
|
},
|
|
{
|
|
displayName: 'Reconnect limit',
|
|
name: 'reconnectLimit',
|
|
type: 'number',
|
|
default: 50,
|
|
description: 'maximum number of reconnect attempts',
|
|
},
|
|
],
|
|
},
|
|
]
|
|
};
|
|
|
|
|
|
async trigger(this: ITriggerFunctions): Promise<ITriggerResponse> {
|
|
|
|
const credentials = this.getCredentials('amqp');
|
|
if (!credentials) {
|
|
throw new Error('Credentials are mandatory!');
|
|
}
|
|
|
|
const sink = this.getNodeParameter('sink', '') as string;
|
|
const clientname = this.getNodeParameter('clientname', '') as string;
|
|
const subscription = this.getNodeParameter('subscription', '') as string;
|
|
const options = this.getNodeParameter('options', {}) as IDataObject;
|
|
const pullMessagesNumber = options.pullMessagesNumber as number || 100;
|
|
const container_id = options.containerID as string;
|
|
const containerReconnect = options.reconnect as boolean || true ;
|
|
const containerReconnectLimit = options.reconnectLimit as number || 50;
|
|
|
|
if (sink === '') {
|
|
throw new Error('Queue or Topic required!');
|
|
}
|
|
|
|
let durable = false;
|
|
|
|
if (subscription && clientname) {
|
|
durable = true;
|
|
}
|
|
|
|
const container: Container = require('rhea');
|
|
|
|
|
|
let lastMsgId: string| number | Buffer | undefined = undefined;
|
|
const self = this;
|
|
|
|
container.on('receiver_open', (context: EventContext) => {
|
|
context.receiver?.add_credit(pullMessagesNumber);
|
|
});
|
|
|
|
container.on('message', (context: EventContext) => {
|
|
|
|
// No message in the context
|
|
if(!context.message)
|
|
return;
|
|
|
|
console.log("New Message on Amqp Trigger from " + container.id + " context conteaineer id: " + context.container.id);
|
|
// ignore duplicate message check, don't think it's necessary, but it was in the rhea-lib example code
|
|
if (context.message.message_id && context.message.message_id === lastMsgId) {
|
|
return;
|
|
}
|
|
lastMsgId = context.message.message_id;
|
|
|
|
let data = context.message;
|
|
|
|
if(options.jsonConvertByteArrayToString === true && data.body.content !== undefined) {
|
|
// The buffer is not ready... Stringify and parse back to load it.
|
|
let cont = JSON.stringify(data.body.content);
|
|
data.body = String.fromCharCode.apply(null,JSON.parse(cont).data);
|
|
}
|
|
|
|
if (options.jsonConvertByteArrayToString === true && data.body.content !== undefined) {
|
|
// The buffer is not ready... Stringify and parse back to load it.
|
|
const cont = JSON.stringify(data.body.content);
|
|
data.body = String.fromCharCode.apply(null, JSON.parse(cont).data);
|
|
}
|
|
|
|
if (options.jsonConvertByteArrayToString === true && data.body.content !== undefined) {
|
|
// The buffer is not ready... Stringify and parse back to load it.
|
|
const content = JSON.stringify(data.body.content);
|
|
data.body = String.fromCharCode.apply(null, JSON.parse(content).data);
|
|
}
|
|
|
|
if (options.jsonParseBody === true) {
|
|
data.body = JSON.parse(data.body);
|
|
}
|
|
if (options.onlyBody === true) {
|
|
data = data.body;
|
|
}
|
|
|
|
|
|
self.emit([self.helpers.returnJsonArray([data as any])]);
|
|
|
|
if (!context.receiver?.has_credit()) {
|
|
setTimeout(() => {
|
|
context.receiver?.add_credit(pullMessagesNumber);
|
|
}, options.sleepTime as number || 10);
|
|
}
|
|
});
|
|
|
|
/*
|
|
Values are documentet here: https://github.com/amqp/rhea#container
|
|
*/
|
|
const connectOptions: ContainerOptions = {
|
|
host: credentials.hostname,
|
|
hostname: credentials.hostname,
|
|
port: credentials.port,
|
|
reconnect: containerReconnect,
|
|
reconnect_limit: containerReconnectLimit,
|
|
username: credentials.username ? credentials.username : undefined,
|
|
password: credentials.password ? credentials.password : undefined,
|
|
transport: credentials.transportType ? credentials.transportType : undefined,
|
|
container_id: container_id ? container_id : undefined,
|
|
id: container_id ? container_id : undefined,
|
|
};
|
|
const connection = container.connect(connectOptions);
|
|
|
|
let clientOptions : ReceiverOptions = {
|
|
name: subscription ? subscription : undefined,
|
|
source: {
|
|
address: sink,
|
|
durable: (durable ? 2 : undefined),
|
|
expiry_policy: (durable ? 'never' : undefined),
|
|
},
|
|
credit_window: 0, // prefetch 1
|
|
};
|
|
connection.open_receiver(clientOptions);
|
|
|
|
|
|
// The "closeFunction" function gets called by n8n whenever
|
|
// the workflow gets deactivated and can so clean up.
|
|
async function closeFunction() {
|
|
container.removeAllListeners('receiver_open');
|
|
container.removeAllListeners('message');
|
|
connection.close();
|
|
}
|
|
|
|
// The "manualTriggerFunction" function gets called by n8n
|
|
// when a user is in the workflow editor and starts the
|
|
// workflow manually.
|
|
// for AMQP it doesn't make much sense to wait here but
|
|
// for a new user who doesn't know how this works, it's better to wait and show a respective info message
|
|
async function manualTriggerFunction() {
|
|
await new Promise((resolve, reject) => {
|
|
const timeoutHandler = setTimeout(() => {
|
|
reject(new Error('Aborted, no message received within 30secs. This 30sec timeout is only set for "manually triggered execution". Active Workflows will listen indefinitely.'));
|
|
}, 3000);
|
|
container.on('message', (context: EventContext) => {
|
|
// Check if the only property present in the message is body
|
|
// in which case we only emit the content of the body property
|
|
// otherwise we emit all properties and their content
|
|
const message = context.message as Message;
|
|
if (Object.keys(message)[0] === 'body' && Object.keys(message).length === 1) {
|
|
self.emit([self.helpers.returnJsonArray([message.body])]);
|
|
} else {
|
|
self.emit([self.helpers.returnJsonArray([message as any])]);
|
|
}
|
|
clearTimeout(timeoutHandler);
|
|
resolve(true);
|
|
});
|
|
});
|
|
}
|
|
|
|
return {
|
|
closeFunction,
|
|
manualTriggerFunction,
|
|
};
|
|
|
|
}
|
|
}
|