moleculer

Moleculer

Moleculer is a fast & powerful microservices framework for NodeJS (>= v6.x).

Website: https://moleculer.services

Documentation: https://moleculer.services/docs

What's included

• Promise-based solution
• request-reply concept
• event bus system
• supports middlewares
• service mixins
• multiple services on a node/server
• built-in caching solution (memory, Redis)
• pluggable transporters (NATS, MQTT, Redis)
• pluggable serializers (JSON, Avro, MsgPack, Protocol Buffer)
• load balanced requests (round-robin, random)
• every nodes are equal, no master/leader node
• auto discovery services
• parameter validation with fastest-validator
• distributed timeout handling with fallback response
• health monitoring, metrics & statistics
• supports versioned services (run different versions of the service)
• official API gateway module

Installation

$ npm install moleculer --save

or

$ yarn add moleculer

Create your first microservice

This example shows you how to create a small service with an add action which can add two numbers.

const { ServiceBroker } = require("moleculer");

let broker = new ServiceBroker({ logger: console });

broker.createService({
    name: "math",
    actions: {
        add(ctx) {
            return Number(ctx.params.a) + Number(ctx.params.b);
        }
    }
});

broker.start();

// Call service
broker.call("math.add", { a: 5, b: 3 })
    .then(res => console.log("5 + 3 =", res))
    .catch(err => console.error(`Error occured! ${err.message}`));

Try it on Runkit

Create a Moleculer project

Use the Moleculer CLI tool to create a new Moleculer based microservices project.

1. Install moleculer-cli globally

   $ npm install moleculer-cli -g
   

2. Create a new project (named first-demo)

   $ moleculer init project-simple first-demo
   

   Press Y on API Gateway & npm install

3. Open project folder

   $ cd first-demo
   

4. Start project

   $ npm run dev
   

5. Open the http://localhost:3000/greeter/welcome?name=world link in your browser. It will call the welcome action of greeter service with a name param via API gateway and returns with the result.

:tada:Congratulations! Your first Moleculer based microservices project is created. Read our documentation to learn more about Moleculer.

Official modules

We have many official modules for Moleculer. Check our list!

Documentation

You can find here the documentation.

Changelog

See CHANGELOG.md.

Roadmap

See ROADMAP.md.

Contributions

We welcome you to join the development of Moleculer. Please read our contribution guide.

License

Moleculer is available under the MIT license.

3rd party licenses

Contact

Copyright (c) 2016-2017 Ice Services

Changelog

0.10.0 (2017-08-20)

Breaking changes

No more nodeID == null in local stuff

In all core modules removed the nullable nodeID. Every places (context, events, $node.* results) the nodeID contains a valid (local or remote) nodeID. On local nodes it equals with broker.nodeID.

Migration guide

Before:

if (ctx.nodeID == null) { ... }
// ---------
events: {
    "users.created"(payload, sender) {
        if (sender == null) { ... }
    }
}

After:

if (ctx.nodeID == ctx.broker.nodeID) { ... }
// ---------
events: {
    "users.created"(payload, sender) {
        if (sender == this.broker.nodeID) { ... }
    }
}

internalActions is renamed to internalServices

The internalActions broker option is renamed to internalServices.