moleculer

Moleculer

Moleculer is a progressive microservices framework for Node.js.

Website: https://moleculer.services

Documentation: https://moleculer.services/docs

What's included

• Promise-based solution
• request-reply concept
• support streams
• support event driven architecture with balancing
• built-in service registry & dynamic service discovery
• load balanced requests & events (round-robin, random, cpu-usage, latency)
• many fault tolerance features (Circuit Breaker, Bulkhead, Retry, Timeout, Fallback)
• supports middlewares
• supports versioned services
• service mixins
• built-in caching solution (memory, Redis)
• pluggable transporters (TCP, NATS, MQTT, Redis, NATS Streaming, Kafka)
• pluggable serializers (JSON, Avro, MsgPack, Protocol Buffer, Thrift)
• pluggable validator
• multiple services on a node/server
• all nodes are equal, no master/leader node
• parameter validation with fastest-validator
• built-in health monitoring & metrics
• official API gateway module and many other modules...

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 and how to call it.

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

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

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

// Start broker
broker.start()
    // Call service
    .then(() => broker.call("math.add", { a: 5, b: 3 }))
    .then(res => console.log("5 + 3 =", res))
    .catch(err => console.error(`Error occurred! ${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 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/ link in your browser. It shows a start page which contains two links to call the greeter service via API gateway.

: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!

Supporting

Moleculer is an open source project. It is free to use for your personal or commercial projects. However, developing it takes up all my free time to make it better and better on a daily basis. If you like Moleculer framework, please support it.

Thank you very much!

Documentation

You can find here the documentation.

Changelog

See CHANGELOG.md.

Security contact information

To report a security vulnerability, please use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.

Contributions

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

License

Moleculer is available under the MIT license.

3rd party licenses

Contact

Copyright (c) 2016-2018 MoleculerJS

Changelog

0.13.13 (2020-02-11)

AMQP 1.0 transporter

Thanks for @vladir95, AMQP 1.0 transporter is available.

Please note, it is an experimental transporter. Do not use it in production yet!

// moleculer.config.js
module.exports = {
    transporter: "amqp10://activemq-server:5672"
};

To use this transporter install the rhea-promise module with npm install rhea-promise --save command.

Transporter options

Options can be passed to rhea.connection.open() method, the topics, the queues, and the messages themselves.

Connect to 'amqp10://guest:guest@localhost:5672'

// moleculer.config.js
module.exports = {
    transporter: "AMQP10"
};

Connect to a remote server

// moleculer.config.js
module.exports = {
    transporter: "amqp10://activemq-server:5672"
};

Connect to a remote server with options & credentials

// moleculer.config.js
module.exports = {
    transporter: {
        url: "amqp10://user:pass@activemq-server:5672",
        eventTimeToLive: 5000,
        heartbeatTimeToLive: 5000,
        connectionOptions: { // rhea connection options https://github.com/amqp/rhea#connectoptions, example:
            ca: "", // (if using tls)
            servername: "", // (if using tls)
            key: "", // (if using tls with client auth)
            cert: "" // (if using tls with client auth)
        },
        queueOptions: {}, // rhea queue options https://github.com/amqp/rhea#open_receiveraddressoptions
        topicOptions: {}, // rhea queue options https://github.com/amqp/rhea#open_receiveraddressoptions
        messageOptions: {}, // rhea message specific options https://github.com/amqp/rhea#message
        topicPrefix: "topic://", // RabbitMq uses '/topic/' instead, 'topic://' is more common
        prefetch: 1
    }
};

Redis Cluster feature in Redis transporter

Thanks for AAfraitane, use can connect to a Redis Cluster with the Redis transporter.

Connect to Redis cluster

// moleculer.config.js
module.exports = {
    transporter: {
        type: "Redis",
        options: {
            cluster: {
                nodes: [
                    { host: "localhost", port: 6379 },
                    { host: "localhost", port: 6378 }
                ]
            }
        }
    }
};

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