Node-nameko-client NPM

node-nameko-client is a library for interacting with Nameko microservices framework.

Usage

This example connects to RabbitMQ and calls send_mail method from mailer service:

var nameko = require('node-nameko-client');

nameko.connect({host: '127.0.0.1', port: 5672}).on('ready', function(rpc) {
    rpc.call('mailer', 'send_mail', ['foo@example.org', 'Hello!', 'It\'s been a lo-o-o-ong time.'], {}, function(e, r) {
        if (e) {
            console.log('Oops! RPC error:', e);
        } else {
            console.error('Success: Result is', r);
        }
    });
});

// You can also use promises. Here's an example with promises & ES6 syntax:

nameko.connect({host: '127.0.0.1', port: 5672})
    .then(
        rpc => rpc.call('mailer', 'send_mail', ['foo@example.org', 'Hello!', 'It\'s been a lo-o-o-ong time.']);
    )
    .then(
        result => console.log('Success: Result is', result);
    )
    .catch(
        error => console.error('Oops! RPC error:', error.stack);
    )
;

Installation

npm install node-nameko-client

Methods

`.connect([config, [callback, [onError]]])`

This method takes one optional argument: a config object. Allowed keys are:

host - RabbitMQ host (default: "127.0.0.1")
port - RabbitMQ port (default: 5672)
login - RabbitMQ username (default: "guest")
password - RabbitMQ password (default: "guest")
exchange - RabbitMQ exchange (default: "nameko-rpc")
timeout - Timeout for waiting for response (in ms, default: 5000)
debug_level - Debug level. Choices are "debug", "info", "warning" or "error" (default: "debug"). Has no effect if logger is provided (see below.)
logger - Custom logger to use (default: null). debug_level will have no effect if you provide it.

callback is called when the connection succeeds, onError is called when a connection error occurs.

If callback is not provided then this method returns Promise.

`.call(service_name, method_name, [args, [kwargs, [callback(e, r)]]])`

Performs RPC call by sending event to the appropriate RabbitMQ queue. args should be a list or undefined, kwargs should be an object or undefined.

If a callback is provided it will be called once a method is complete. Otherwise this method returns Promise.

Using with ExpressJS

They also play well together:

var nameko = require('node-nameko-client');
var express = require('express');

var app = express();
var rpc = nameko.connect({host: '127.0.0.1', port: 5672});

rpc.on('ready', function() {
    console.log('Connected to AMQP.');

    app.listen(9000, function() {
        console.log('Server started on port 9000.');
    });
});

app.get('/', function(req, res) {
    rpc.call('mailer', 'ping', ['foo@example.org', 'Hello!', 'It\'s been a lo-o-o-ong time.'], {}, function(e, r) {
        if (e) {
            res.send('Oops! RPC error: ' + e);
        } else {
            res.send('Success: Result is ' + r);
        }
    });
});

What's on the roadmap?

Promises
Reusing reply queues for better performance
Fixing some unknown hard-coded values (already have information from Nameko devs regarding this, will fix soon)
Adding support for event broadcasting (e. g. BROADCAST & SINGLETON message types)
Adding tests