[Self-hosted] New custom node environment variable and custom attribute

Questions
1

Hello everyone! I recently decided to create a custom node which is using the webhooksMethods create and delete.

My goal, at the moment of the creation, is to register the node in a third-party app and get a unique ID, so what I need to do is to get access to environments variables to understand what is the environment I am trying to connect with, and once I get the response from the client, I would like to store the value to be used in the delete method.

Here is my code:

export class CustomTrigger implements INodeType {
	description: INodeTypeDescription = {
		displayName: 'Custom Trigger',
		name: 'customTrigger',
		description: '...',
		icon: '...',
		group: ['trigger'],
		version: 1,
		defaults: {
			name: 'Custom Trigger',
			color: '...',
		},
		inputs: [],
		outputs: ['main'],
		credentials: [
			{
				name: 'myCustomCredentials',
				required: true,
			}
		],
		webhooks: [
			{
				name: 'default',
				httpMethod: 'POST',
				path: 'customTrigger',
				responseMode: 'onReceived',
			},
		],
		properties: [
			{
				displayName: 'Event Type',
				name: 'eventType',
				type: 'options',
				required: true,
				default: '',
				options: [
					{
						name: 'Option 1',
						value: 'option1',
					},
					{
						name: 'Option 2',
						value: 'option2',
					}
				],
			},
		],
	};

	webhookMethods = {
		default: {
			async checkExists(this: IHookFunctions): Promise<boolean> {
				// TODO: Check if this workflow is subscribed already to the external service
				return false;
			},
			async create(this: IHookFunctions): Promise<boolean> {
				const credentials = this.getCredentials('customCredentials');
				const webhookUrl = this.getNodeWebhookUrl('default');
				const event = this.getNodeParameter('eventType') as string;
				
                                // TODO: Subscribe to the external service and get the ID
				// TODO: Store the webhook ID so we can delete it later
				const client = platformClient({ 
					**endpoint: "https://url-of-external-service.io", // This should be read from an environment variable defined in cli/config/index**
					authorizationToken: credentials.apiKey
				})

				const newSubscription = await client.subscribeToWebhook({
					url: webhookUrl,
					eventTypes: event
				})
				
				// TODO: We need to persist the **newSubscription.id**
				return true;
			},
			async delete(this: IHookFunctions): Promise<boolean> {
                                // TODO: Similar to create but here we will remove the subscription
				return true;
			},
		},
	};

	async webhook(this: IWebhookFunctions): Promise<IWebhookResponseData> {
		const req = this.getRequestObject();
		const { body } = req as { body: IDataObject };
		return {
			workflowData: [[{ json: body }]],
		};
	}
}

So what I need to do is 1st, read an environment variable I have defined as part of cli/config/index.ts, and then I need to persist the value either, as part of the Node information or the Workflow.

How can I do this?

2

Hi @b3nshi! First of all, welcome to the community!

I think @RicardoE105 would be best placed to answer this question, so I have flagged this to him :slight_smile:

1 Like
4

First, you should not make changes to cli/config/index.ts and that is also not necessary. You can read an environment variable the same way inside of n8n than in any other Node.js application, with process.env.VARIABLE_NAME.

You can save data in the static data of a node like most Trigger-Nodes do:

const webhookData = this.getWorkflowStaticData('node');
webhookData.yourVariable = 1;

One example would be the GitHub-Trigger Node:

1 Like
5

Thank you so much for your answers, now the node is working as expected!

The example you shared was really helpful! I thought the way to add new env variables was via the config/index.ts just to validate before using them, but it makes sense what you said since the node is not part of the base functionality.

6

Glad to hear that it was helpful.

Yes, we discourage generally adding anything to the n8n-core code. That can cause potential issues and makes updating n8n more complicated.

Have fun!

1 Like