Hydra Integration Module

Integrating third-party Node.js web frameworks with Hydra, the simplest way.

Hydra is a NodeJS package, which facilitates building distributed applications such as Microservices. (https://www.hydramicroservice.com/)

The magic thing with Hydra is that with a minimum setup, your micro-service get 'superpowers':

Distributed Computing
Application Clusters + Load Balancer
High Availability
Centralized Proxy Router
Realtime Messaging
Service Discovery, Monitoring and Management
... and much more (https://www.hydramicroservice.com/)

By using this module, you will be able to easily integrate your prefered web framework with hydra. Just keep reading...

Integrated frameworks

At the moment, the following frameworks are supported:

Express: Fast, unopinionated, minimalist web framework for Node.js... (http://expressjs.com/)
Hapi: A rich framework for building applications and services, hapi enables developers to focus on writing reusable application logic instead of spending time building infrastructure... (https://hapijs.com/)
Koa: Koa is a new web framework designed by the team behind Express, which aims to be a smaller, more expressive, and more robust foundation for web applications and APIs... (http://koajs.com/)
Sails.js: Sails makes it easy to build custom, enterprise-grade Node.js apps... (http://sailsjs.com/)
Restify: Restify is a node.js module built specifically to enable you to build correct REST web services... (http://restify.com/)
Restana: Super fast and minimalist web framework for building REST micro-services... (https://github.com/jkyberneees/ana)
Native Hydra Service: Hydra services are ideal for making distributed API calls through HTTP or real-time events management... (https://www.hydramicroservice.com/)

Getting Started

Next we will explain you how to create and express based micro-service on top of hydra:

IMPORTANT: Hydra depends on Redis database server for storage, cache and messaging. In case you don't have it yet: https://www.hydramicroservice.com/docs/quick-start/step1.html

Install dependencies:
```
npm i hydra hydra-integration express --save
```
Express is a dependency here because in the next example we use express, it could be koa or hapi, or any of the supported frameworks.
Create and edit app.js file: ```js const HydraServiceFactory = require('hydra-integration').HydraServiceFactory; const express = require('express'); const router = express.Router();

const factory = new HydraServiceFactory({ hydra: { 'serviceName': 'express-service-test', 'serviceDescription': 'Basic express service on top of Hydra', 'serviceIP': '127.0.0.1', 'servicePort': 3000, 'serviceType': 'express', 'serviceVersion': '1.0.0', 'redis': { 'host': '127.0.0.1', 'port': 6379, 'db': 15 } } });

factory.init().then(factory => factory.getService(service => { router.get('/welcome', (req, res) => res.send('Hello World!')); service.use('/v1', router); }));

Alternative way of getting the service instance by passing config params to the builder (if supported):
```js
factory.init().then(factory => factory.getService({
  // optional config params here to be passed to the building strategy
  bootstrap: service => {
    router.get('/welcome', (req, res) => res.send('Hello World!'));
    service.use('/v1', router);
  }
}));

To use hydra-integration as a plugin see: The HydraIntegrationPlugin class

Run your service:
Single process:
```
node app.js
```
Optionally you can run multiple processes with PM2:
```
pm2 start app.js -i 4
```
Test your service using a Web browser at: http://localhost:3000/v1/welcome
Test the service using the hydra-cli (https://www.hydramicroservice.com/docs/tools/hydra-cli/getting-started.html):

List service routes

hydra-cli routes express-service-test

{
"serviceName": [
  "[GET]/_health",
  "[GET]/v1/welcome"
]
}

Invoke the [GET]/v1/welcome service endpoint:

hydra-cli rest express-service-test:[GET]/v1/welcome

{
"headers": {
  "x-powered-by": "Express",
  "content-type": "text/html; charset=utf-8",
  "content-length": "12",
  "etag": "W/\"c-Lve95gjOVATpfV8EL5X4nxwjKHE\"",
  "date": "Wed, 05 Apr 2017 21:22:51 GMT",
  "connection": "close"
},
"body": "Hello World!",
"statusCode": 200
}

Demos

Demos available into demos folder on the git repository: https://github.com/jkyberneees/hydra-integration

Next Topics

Complementary Topics

The Hydra Router

Détail du package