Description

Azure Service Bus is a fully managed enterprise message broker with message queues and publish-subscribe topics (in a namespace). Service Bus is used to decouple applications and services from each other, providing the following benefits:

• Load-balancing work across competing workers
• Safely routing and transferring data and control across service and application boundaries
• Coordinating transactional work that requires a high-degree of reliability

Installation

To start building Azure Service Bus-based microservices, first install the required packages:

$ npm i nestjs-azure-service-bus-transporter

Server

To use the Azure Service Bus strategy, pass the following options object to the createMicroservice() method:

//  main.ts

const app = await NestFactory.createMicroservice<MicroserviceOptions>(
  AppModule,
  {
    strategy: new AzureServiceBusServer({
      connectionString:
        "Endpoint=sb://<Name>.servicebus.windows.net/;SharedAccessKeyName=<SharedAccessKeyName>;SharedAccessKey=<SharedAccessKey>",
      options: {},
    }),
  }
);

To use in a hybrid application, pass the following options object to the connectMicroservice() method:

//  main.ts
const app = await NestFactory.create(AppModule);

await app.connectMicroservice({
  strategy: new AzureServiceBusServer({
    connectionString:
      "Endpoint=sb://<Name>.servicebus.windows.net/;SharedAccessKeyName=<SharedAccessKeyName>;SharedAccessKey=<SharedAccessKey>",
    options: {},
  }),
});

await app.startAllMicroservices();
await app.listen(3000);

Options

The Azure Service Bus strategy exposes the properties described below.

Queue Consumer

To access the original Azure Service Bus message use the Queue decorator as follows:

import { Queue } from 'nestjs-azure-service-bus-transporter';
import { ServiceBusReceiver } from '@azure/service-bus';
import { Payload, Ctx } from '@nestjs/microservices';
@Queue({
    queueName: 'sample-topic',
    receiveMode: 'peekLock', // or receiveAndDelete
    options:{
      autoCompleteMessages:true,
    }
  })
getMessages(
  @Payload() message: ServiceBusMessage,@Ctx() context:AzureServiceBusContext) {
   const serviceBusReceiver:ServiceBusReceiver= context.getArgs()[0];
   console.log(message);
}

Options

Topic Consumer

To access the original Azure Service Bus message use the Subscription decorator as follows:

import { Topic } from 'nestjs-azure-service-bus-transporter';
import { Payload, Ctx } from '@nestjs/microservices';
import { ServiceBusReceiver } from '@azure/service-bus';
@Topic({
    topic: 'sample-topic',
    subscription: 'sample-subscription',
    receiveMode: 'peekLock', // or receiveAndDelete
    options:{
      autoCompleteMessages:true,
    }
  })
getMessages(@Payload() message: ServiceBusMessage) {
  const serviceBusReceiver: ServiceBusReceiver = context.getArgs()[0];
  console.log(message);
}

Options

Client

//  app.module.ts

@Module({
  imports: [
    AzureServiceBusModule.forRoot([
      {
        name: 'SB_CLIENT',
        connectionString: 'Endpoint=sb://<Name>.servicebus.windows.net/;SharedAccessKeyName=<SharedAccessKeyName>;SharedAccessKey=<SharedAccessKey>',
        options: {},
      },
    ]),
  ]
  ...
})

// or

@Module({
  imports: [
    AzureServiceBusModule.forRootAsync([
      {
        name: 'SB_CLIENT',
        useFactory: (configService: ConfigService) => ({
          connectionString: configService.get('connectionString'),
          options: {}
        }),
        inject: [ConfigService],
      },
    ]),
  ]
  ...
})

Since AzureServiceBusModule is a global module you can inject Clients into other modules providers and even controllers.

//example.service.ts
//provider
@Injectable()
export class exampleService {
  constructor(
    @Inject("SB_CLIENT") private readonly sbClient: AzureServiceBusClientProxy
  ) {}
}

//example.controller.ts
//controller
@Controller("example")
export class exampleController {
  constructor(
    @Inject("SB_CLIENT") private readonly sbClient: AzureServiceBusClientProxy
  ) {}
}

Producer

Event-based

const pattern = {
  name: "sample-topic", // topic/queue name
  options: {},
};
const data = {
  body: "Example message",
};

this.sbClient.send(pattern, data).subscribe((response) => {
  console.log(response); // reply message
});

Message-based

const pattern = {
  name: "sample-topic", // topic/queue name
  options: {},
};
const data = {
  body: "Example message",
};
this.sbClient.emit(pattern, data);

Stay in touch

• Author - Santiagomrn
• Author - Niurmiguel

License

Nestjs Azure Service Bus is MIT licensed.