NestJs Eventbridge Lambda function - node.js

Question

I have a system writed in using NestJs and serverless framework were each endpoint is a lambda function on aws. One of the functions is not an endpoint, but a trigger from AWS eventbridge. As this function is not an endpoint it cannot be included on a NestJs module since it have to be exported separatelly. My problem is that when the event comes to Eventbridge and triggers the lambda I have to call a NestJs service but I'm not able to do this, since the lambda function is outside NestJs environment. Is that a way for me to call a NestJs service from outside the module?
Here is the serverless framework configs
functions:
function 1(NestJs controller):
handler: src/lambda.handler
events:
- http:
cors: true
method: post
path: entrypoint for function 1
Function 2 (External from NestJs modules):
handler: path to lambda function
events:
- eventBridge:
eventBus: eventbus name
pattern:
source:
- source
Currently I'm using axios to call another NestJs endpoint to just pass the received payload. As you can see on the lambda function file:
import { Context, Handler } from 'aws-lambda'
import axios from 'axios'
export const handler: Handler = async (event: any, context: Context) => {
return await axios
.post(
'lambda function production url',
event.detail
)
.then((data) => {
console.log('data', data)
return data
})
.catch((error) => {
console.log('error', error)
return error
})
}
Here is the controller of lambda function 1
import { Body, Controller, Post } from '#nestjs/common'
import { MyService } from './enrichment.service'
#Controller('function1')
export class EnrichmentController {
constructor(private readonly myService: MyService) {}
#Post('entrypoint')
sendForm(#Body() body) {
return this.myService.start(body)
}
}
and here is the service
import { forwardRef, Inject, Injectable } from '#nestjs/common'
import { EventbridgeService } from '../eventbridge/eventbridge.service'
import { CampaignsService } from '../campaigns/campaigns.service'
import { UploadedDataService } from '../uploaded-data/uploaded-data.service'
#Injectable()
export class MyService {
constructor(
private readonly anotherService: AnotherService,
) {}
async start(body) {
return this.anotherService.updateData(body)
}
}
The question is: Is that a way to call all this NestJs structure from the function file, since it is outside NestJs modules and since the trigger for this function is not an http request but a trigger from Eventbridge? Thank you so much.

Answer 1

You can use a "Standalone" Nest application and pass the event data directly to MyService

Answer 2

You can use NEstJs standalone app, and make your handler like this
export const checkDeletion: Handler = async (event: any, context: Context) => {
async function bootstrap() {
const app = await NestFactory.createApplicationContext(AppModule);
await app
.select(SchedulerModule)
.get(SchedulerService, { strict: true })
.runScheduler();
}
await bootstrap();
};
After that call your handler from serverless.yaml like
functions:
followup-emails:
environment:
STAGE: ${opt:stage}
name: followup-emails-${opt:stage}
handler: src/lambda.checkDeletion
events:
- schedule: rate(1 day)