bk-rabbitmq-rpc

This is a very opinionated abstraction over amqplib to help simplify the implementation of RPC messaging patterns on RabbitMQ.

!IMPORTANT! - bk-rabbitmq-rpc needs nodejs >= 8.x.

Features:

• Creation of RPC services (client & server)
• Attempt to gracefully handle lost connections and channels
• Connections have a backoff policy of exponential delay randomized: ~1s, ~2s, ~4s, ~8s then stable at ~8s, ~8s...

Installation

npm install bk-rabbitmq-rpc

Getting started

On RPC server :

const RabbitmqRPC = require('bk-rabbitmq-rpc');

const client = new RabbitmqRPC();

// create a your first service
const service = client.createService('myFirstService',{ autoStartConsume: true })

// handle a service method on rpc server
service.handle('myMethod', function(data){
	return data;
});

// or if you don't use option autoStartConsume for rpc server
service.startConsume();

On RPC Client :

const RabbitmqRPC = require('bk-rabbitmq-rpc');

const client = new RabbitmqRPC();

// on rpc client ask the service method
client.request('myFirstService','myMethod',data).then((result) => {
	console.log(result);
})

API Reference

new RabbitmqRPC(options)

Return a new RabbitmqRPC client. options are :

• url : URL to connect to RabbitMQ (default : amqp://guest:guest@localhost:5672/)
• logLevel : Log level (default : info)
• logName : Log name for Bunyan = (default : RabbitmqRPC)
• exchangeName : Exchange name for handle RPC request (default : RabbitmqRPC)
• log : Custom log instance (require to implement function trace, debug, info, warn and error)
• responseQueue : If true, the responseQueue will be generated, it's possible to use a string to define. Use false for no responseQueue (default : true)
• timeout : Timeout for rpc request in ms (default : 10000)

{client} request(serviceName, method, data, options)

Request a method on a service.

• serviceName string for the service name.
• method is the method name, you have to use alphanum string for the method name.
• data is the data send to the client.
• options options for the request with the following properties :
  • timeout : specify timeout for rpc request in ms. Defautlt is the time specify in the constructor. This function return a Promise.

{client} apply(serviceName, method, data, options)

Request a method on a service but without response.

• serviceName string for the service name.
• method is the method name, you have to use alphanum string for the method name.
• data is the data send to the client.
• options options for the request with the following properties :
  • timeout : specify timeout for rpc request in ms. Warning : defautlt is no timeout !

This function return a Promise.

{client} createService(serviceName, options)

Return a service object

• serviceName string for the service name.
• options are :
  • autoStartConsume : If the service start to consume RPC message at the beginning (default : false)
  • limit : Concurent limit request for the service. By default there is no limit.

{service} handle(method,function(data) {})

Handle a method for the service.

• method is the method name, you have to use alphanum string for the method name.
• function is the function called. It can be a function or a promise. The return of the function is return to the client. The function take one arg whose is the data send by the client.

!IMPORTANT! - if you don't use the option autoStartConsume: true on service constructor don't forget to call service.startConsume() to handle the RabbitmqRPC message.

Contributing

First off, thanks for your interest and for wanting to contribute!

Run tests

# With docker
npm run build-image #to build rabbitmq Image
npm run start-image #to start rabbitmq on localhost
# Or provide your own local rabbitmq install

# run tests
npm test

# run lint
npm run lint

# run coverage
npm run coverage

TODO

• Add better coverage test
• Add better reconnection method => sometime the connections aren't really closed
• ...

License

MIT License

Copyright (c) 2017 Beekast