@21jumpclick/service-messenger
v1.0.18
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Amqp lib to send and receive messages from different applications
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@21jumpclick/service-messenger
Send message and response to event with ts decorators
Before start
This library use a rabbitmq instance to communicate. You can spin up a developpment message broker with docker using:
docker run -d --rm --name my-rabbit -p 15672:15672 -p 5672:5672 rabbitmq:3-management
In a production environment, we recommand using a replicated RabbitMQ cluster.
Installation
Warning, this package is not a DI manager and use other Dependency Injection manager to function properly. You can run this library with:
The author will try to add support for new depency injectors in the futures.
You can install the package with just
npm i --save @21jumpclick/service-messenger
Documentation
You can start the amqp lib by initializing the Messenger singleton
TypeDI
Init your Messenger in the entrypoint of your app (index.ts) :
import Container, { Service } from "typedi";
import { Messenger } from "@21jumpclick/service-messenger";
Messenger.init({
rootDir: __dirname,
name: "my-node-name",
verbose: process.env.NODE_ENV !== "production",
rabbit: {
host: process.env.RABBITMQ_HOST,
port: process.env.RABBITMQ_PORT,
user: process.env.RABBITMQ_USER,
password: process.env.RABBITMQ_PASSWORD,
},
di: Container,
});
TSED.io
For tsed, you can init your Messenger in your main configuration
import { AfterInit } from "@tsed/common";
import { Configuration, Inject, InjectorService } from "@tsed/di";
import { Messenger } from "@21jumpclick/service-messenger";
@Module()
export class Server implements AfterInit {
@Inject()
private injector: InjectorService;
$afterInit() {
Messenger.init({
rootDir: __dirname,
name: "my-node-name",
verbose: process.env.NODE_ENV !== "production",
rabbit: {
host: process.env.RABBITMQ_HOST,
port: process.env.RABBITMQ_PORT,
user: process.env.RABBITMQ_USER,
password: process.env.RABBITMQ_PASSWORD,
},
di: this.injector,
});
}
}
Configuration
Library configuration object
| Name | Default | Description | | ------- | ---------------------- | ---------------------------------------------------------------------------------------- | | rabbit | see below the defaults | The rabbitmq credentials used to connect to the server | | di | undefined | The di service usued in this package. | | name | undefined | The service name of your application, usued to receive message from other services | | verbose | false | Logs every transactions and payloads | | rootDir | undefined | The root directory where you implement your @Amqp decorators (get folder and subfolders) |
RabbitMQ configuration object
| Name | Default | Description | | -------- | --------- | ----------------------------------------- | | host | localhost | The IP or hostname of the rabbitmq server | | port | 5672 | The port of the rabbitmq server | | user | guest | The user of the rabbitmq server | | password | guest | The password of the rabbitmq server |
How to use
To emit to rabbitmq
import { Messenger } from "@21jumpclick/service-messenger";
@Service()
export class MyService {
async getMemberInformation(memberId: string) {
const member = await Messenger.invoke<{ user: string }>(
"payment.member-informations",
{
memberId,
}
);
// you should receive an object from the payment service running in a different application.
}
// If you just send data, without receiving anything, you can call the publish method. It's much smaller in compute requirements (avoid the round trip)
sendUserUpdate(user: unknown) {
Messenger.publish("users.update-user", user);
}
// If you want to, for example, refresh a list on all available consumers, you can you the broadcast method
broadcastListenerService(user: unknown) {
Messenger.broadcast("users.add-user-listener", user);
}
}
Now, this is how to receive and response to events :
In your payment service, just use the @Amqp decorarator
// first, import your mesh service
import { Amqp, Message, Origin } from "@21jumpclick/service-messenger";
@Service()
export class MyService {
constructor(private db: Database) {}
// Get the raw payload sent from `MyService`
@Amqp("member-informations")
async getMemberInformation(@Message() payload: { memberId: string }) {
const member = await this.db.getUserFromId(payload);
return member;
}
// Get a specific property from the sent message
@Amqp("member-informations")
async getMemberInformation(@Message("memberId") payload: string) {
const member = await this.db.getUserFromId(payload);
return member;
}
// You can also get the instance that send the request (this is the name parameter of the service that sent the request)
@Amqp("member-informations")
async getMemberInformation(
@Message("memberId") payload: string,
@Origin() origin: string
) {
const member = await this.db.getUserFromId(payload);
return member;
}
}