Create your first microservice 🚀


Create your first microservice 🚀

Using web-bridge and weave db

Kevin ries
Posted on 25. May 2019 | 2 Min

We will use the following tools:

  • Node.js version 10.10
  • Docker
  • REDIS

But first, what is a microservice?

A microservice is a single self-contained unit which, together with many others, makes up a large application. By splitting your app into small units every part of it is independently deployable and scalable, can be written by different teams and in different programming languages and can be tested individually

I would like to announce that as the outcome of a half year’s hard work I created a brand-new microservices framework for NodeJS.

What is Weave?

Weave is an open-source fast & flexible framework, licensed under MIT. It contains most of all important microservices features (service registry, auto-discovery, load balancing, circuit-breaker…etc).

Key features

  • Written in Javascript
  • Promise-based solution
  • request-reply concept
  • support event driven architecture with balancing
  • supports middlewares
  • built-in caching solution (memory, Redis)
  • pluggable transporters (NATS, Redis)
  • load balanced requests (round-robin, random)
  • auto discovery services
  • health monitoring, metrics & statistics

How to start

Weave is available as an npm package. You can install it with npm or yarn

$ npm install @weave-js/cli

Usage This simple example show you how easy it is to create a service in Weave and call it.

const { ServiceBroker } = require('@weave-js/core')
// Create broker
let broker = new ServiceBroker({ logger: console })
// Create a service
broker.createService({
    name: "math",
    actions: {
        // You can call it as broker.call("math.add")
        add(ctx) {
            return Number(ctx.params.a) + Number(ctx.params.b);
        }
    }
})
// Start broker
broker.start()
// Call actions of service
broker.call("math.add", { a: 5, b: 3 }).then(res => console.log("5 + 3 =", res))

As you can see above, we created a math service which has an addaction. This action is able to add two numbers, the values of “a” and “b” parameters. After it created, we can call it with thebroker.call method. The first parameter is the calling path (service name + action name), the second parameter is the params which is passed to the action handler wrapped to a Context object.

You can try it in your browser on Runkit!

How to create a project

Use the Weave CLI tool to create a new Weave based microservices project. Install Weave-cli globally

npm install Weave-cli -g
  1. Create a new project (named Weave-demo)
weave create project test-project

Press Yes on all questions.

This starter project template creates a sample service (greeter) with Jest tests and an API Gateway.

  1. Open project folder and start it
cd Weave-demo
npm run dev
  1. Open the http://localhost:3000/api/greeter/hello link in your browser. It will call the hello action of greeter service.
  2. Open the http://localhost:3000/api/greeter/welcome?name=world link to call the welcome action of greeter service.

Congratulations! You have just created your first Weave based microservices project. Welcome to the microservices world! If you want to learn more about the Weave framework, check out our website https://weave.fachwerk.io or github.