PIPA GATEWAY

A NodeJS module to help you create an API Gateway in an easy way.

Why PIPA GATEWAY

The concept of PIPA GATEWAY is similar to PipaJS, to enable developer to create an orchestrator or an API Gateway or a proxy in easy way.

Installation

$ npm install pipa-gateway

var express = require('express')
var app = express()
var PipaGateway = require('pipa-gateway');

// PipaGateway
// @param   object      Express app
// @param   string      File json config
// @param   string      Middleware folder

var pipaGateway = new PipaGateway(app, { configPath: 'config.json', middlewarePath: 'middleware' });
pipaGateway.open();

app.listen(9000);

How-To

There are 3 features in pipa gateway, proxy, parallel and chain.

PROXY

Proxy will forward your request to services.

{
   "GET /users": {
    "type": "proxy",
    "service":
      {
        "name": "users",
        "url": "https://jsonplaceholder.typicode.com/users"
      }
  },
  "GET /user/:id": {
    "type": "proxy",
    "middlewares":["Auth.ensureAuth"],
    "service":
      {
        "name": "user",
        "url": "https://jsonplaceholder.typicode.com/users/:id"
      }
  }
}

PARALLEL

Parallel will request parallel to multilple services.

{
    "GET /parallel": {
        "type": "parallel",
        "services": [
          {
            "name": "user",
            "url": "https://jsonplaceholder.typicode.com/users"
          },
          {
            "name": "post",
            "url": "https://jsonplaceholder.typicode.com/posts"
          }
        ]
    }
}

Chain

Chain will request chain to multiple services, the next request will process after previous request successfully and can set parameter to the next request based on result on previous request.

{
   "GET /chain/:id": {
    "type": "chain",
    "services": [
      {
        "name": "user",
        "url": "https://jsonplaceholder.typicode.com/users/:id"
      },
      {
        "name": "post",
        "url": "https://jsonplaceholder.typicode.com/posts?userId={user.id}",
        "body":{
          "userId":"{user.id}"
        }
      }
    ]
  }
}

Prefix URL

If you need to add prefix, you can add prefix field in the configuration file. For example, this request from http://example.com/my-prefix/users will be proxied to https://jsonplaceholder.typicode.com/users

{
  "domain": {
    "sample": "http://example.com"
  },
  "prefix": "/my-prefix",
  "routes": {
    "GET /users": {
      "type": "proxy",
      "service":
        {
          "name": "users",
          "url": "https://jsonplaceholder.typicode.com/users"
        }
    }
  }
}

You can also put prefix in the environment variables. It really useful if you have multiple server environments (DEV, STAGING, PROD, etc.) and each enviroment have different prefix. To achive that, you have to add prefix in enviroment variable begin with PIPA_GATEWAY_PREFIX_. Example:

PIPA_GATEWAY_PREFIX_EXAMPLE=/example

{
  "domain": {
    "sample": "http://example.com" 
  },
  "prefix": "${prefix.go_example}",
  "routes": {
    "GET /users": {
      "type": "proxy",
      "service":
        {
          "name": "users",
          "url": "https://jsonplaceholder.typicode.com/users"
        }
    }
  }
}

Set domain from Enviroment Variables

In a real world, you may need to have multiple server enviroments (DEV, STAGING, PROD, etc.) If we define the domain inside the json file, we can only have 1 enviroment. So, to cater the issue, you have to define the domain in the enviroment variables instead.

Every environment variable which starts with PIPA_GATEWAY_DOMAIN_ will be added to domain object.

Example of .env file:

const domainObject = {
  "PIPA_GATEWAY_DOMAIN_SAMPLE": "http://example.com",
  "PIPA_GATEWAY_DOMAIN_TESTING": "http://testing.com"
}  

Note: if you defined domain both in the json file and environment variables, the one defined in json file will be replaced.

Code Example

You can try to run the code example in example folder.

License

Apache-2.0

Contributors

Faris

Septiyan Andika

Habib Ridho