Make HTTP Request To Self in NodeJS / ExpressJS

Question

I'm building an NPM module that needs to make an HTTP request to itself (the running web server). For example:

var url = "http://127.0.0.1:" + (process.env.PORT || 3000) + path;
request(url, function(error, response, body){ 
  ...
});

Is there a way to process a request through the NodeJS pipeline without actually doing an HTTP request?

Or is there a better way to form the URL? I'm nervous that 127.0.0.1 isn't the most robust way to handle this for production sites.

Answer 1

Self Consuming JSON API

In a self consuming JSON API, you define some functionality in some standalone controller functions and then wire the functionality up to express after the fact. Let's use a library application as an example:

books.js

module.exports = {
  browse: function () {
      return Book.findAll()
  },
  read: function (options) {
      return Book.findById(options.book)
  },
  processLateFees: function () {
      // Do a bunch of things to process late fees
  }
}

to-http.js

In this file we build a function that converts a controller function to an HTTP route. We take the query params and pass that to our controller as options:

module.exports = function toHTTP (func) {
    return function (req, res) {
         func(req.params).then(function (data) {
             res.send(data)
         })
    }
}

router.js

And then we connect up our controller to our http router

var express = require('express')
var books = require('./books')
var toHTTP = require('./to-http')

var app = express()
app.get('/books', toHTTP(books.browse))
app.get('/books/:book', toHTTP(books.read))
app.get('/batch-jobs/process-late-fees', toHTTP(books.processLateFees))

So we now have an express application connected up to controller functionality. And the wonderful thing is that we can call these controller functions manually too.

var books = require('./books')
books.processLateFees().then(function () {
    // late fees have been processed
})

If you need a more in depth example of this, the Ghost blog codebase is built around this pattern . It is a very informative read.

Answer 2

You can put that method inside your Model or Controller and call it inside the app if you just have one nodejs application, it needs fewer resources than to create a new request.

If you have more than one nodejs apps (or other services), it is normal to create a request to other web services with specific URL and port.

Answer 3

I do it in one of my project and that works fine. I use it in dev and prod without issues so far, because I use several nodejs applications with 3 differents web services that call themself to log in or check auhtentication. I use both express.js and sails.js (based on express.js)

Answer 4

我认为使用请求模块是可以接受的，它非常快，我在进行单元测试时使用这种方法