Custom transport

A custom transport allows you to define a new microservice client and server for communicating between the NestApplication and NestMicroservice contexts. You may want to create a custom transport strategy for a number of reasons: you or your company already have a message broker service that is does not have a built-in Nest.js transport, or you need to customize how one of the built-in transports works. For the purpose of our example, we will work through implementing a new RabbitMQ transport.

export class RabbitMQTransportServer extends Server implements CustomTransportStrategy {
    private server: amqp.Connection = null;
    private channel: amqp.Channel = null;

    constructor(
        private readonly url: string,
        private readonly queue: string
    ) {
        super();
    }
}

Nest.js requires all custom transports to implement the CustomTransportStrategy interface. This forces us to define our own listen and close methods. In our example, we connect to...