@ecobee/nodejs-gcloud-pubsub-module
v0.8.0
Published
A GCloud Pub/Sub module for NestJS
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NodeJS GCloud Pub/Sub module
A Google Cloud Pub/Sub library for the NestJS framework. Easily subscribe or publish to topics in Google Pub/Sub.
Features
- Module for sending messages on topics
- Microservice to subscribe to topics in controllers
Todo
- Add Module for subscribing to topics
- Add Microservice client for sending messages on topics
Installation
Yarn
yarn add @ecobee/nodejs-gcloud-pubsub-module
NPM
npm install @ecobee/nodejs-gcloud-pubsub-module --save
Usage
Please refer to the interfaces file to understand parameter and object requirements.
Publish to a topic
Publishing topics follows the classic NestJS pattern of importing a module and injecting a service via dependency injection
Module Setup
Import this module into your module
import { Module } from '@nestjs/common';
import { GcloudPubSubModule } from 'nodejs-gcloud-pubsub-module'
import * as path from 'path';
@Module({
imports: [
GcloudPubSubModule.forRoot(moduleOptions: GcloudPubSubModuleOptions),
],
})
export class AppModule {}
If you need to populate the moduleOptions
with dynamic configuration data use the forRootAsync
method. The following example pulls configuration objects using the nestjs-config module
import { Module } from '@nestjs/common'
import { GcloudPubSubModule } from 'nodejs-gcloud-pubsub-module'
import { ConfigService } from 'nestjs-config'
import * as path from 'path'
@Module({
imports: [
GcloudPubSubModule.forRootAsync({
useFactory: (config: ConfigService) => {
const authOptions = config.get('pubsub.authOptions')
const publishOptions = config.get('pubsub.publishOptions')
return {
authOptions /* Authentication options */,
publishOptions /* Message publishing options (Optional) */,
}
},
inject: [ConfigService],
}),
],
})
export class AppModule {}
Service
With the module imported you can now publish messages to topics
import { Injectable } from '@nestjs/common'
import { GcloudPubSubService } from 'nodejs-gcloud-pubsub-module'
const topic = 'projects/MyProjectId/topics/MyTopic'
@Injectable()
export class MyService {
constructor(private readonly gcloudPubSubService: GcloudPubSubService) {}
async publish(payload: PubSubMessage) {
const serializedPayload = JSON.stringify(payload)
return await this.gcloudPubSubService.publishMessage(topic, serializedPayload)
}
}
Subscribing to topics
To subscribe to pubsub message topics we leverage a custom NestJS Microservice. This has the benefit of allowing us to decorate our controllers as we would for standard HTTP requests.
Using a Microservice alongside HTTP can be accomplished by creating a Hybrid NestJS application. Refer to this example to see how this is accomplished.
Microservice setup
import { NestFactory } from '@nestjs/core'
import { GCloudPubSubServer } from 'nodejs-gcloud-pubsub-module'
import { ApplicationModule } from './app.module'
async function bootstrap() {
const app = await NestFactory.create(ApplicationModule)
const GCloudPubSubServerOptions = {
authOptions: {/* Authentication options */}),
subscriptionIds: ['subscription-name'],
subscriberOptions: {/* https://googleapis.dev/nodejs/pubsub/latest/global.html#SubscriberOptions */}
}
app.connectMicroservice({
strategy: new GCloudPubSubServer(GCloudPubSubServerOptions),
})
await app.startAllMicroservicesAsync()
await app.listen(3001)
}
bootstrap()
Controller
import { Controller } from '@nestjs/common'
import { Message } from '@google-cloud/pubsub'
import { EventPattern } from '@nestjs/microservices'
@Controller('mycontroller')
export class EntitlementController {
@EventPattern('subscription-name')
async handleCreateEntitlement(message: Message) {
const { data } = message
const messageData = JSON.parse(data.toString())
// do stuff with the message
message.ack()
}
}