how to require from URL in Node.js

Install the module first :

npm install require-from-url

And then put in your file :

var requireFromUrl = require('require-from-url/sync');
requireFromUrl("http://example.com/nodejsmodules/myModule.js");

If you want something more like require, you can do this:

var http = require('http')
  , vm = require('vm')
  , concat = require('concat-stream') 
  , async = require('async'); 

function http_require(url, callback) {
  http.get(url, function(res) {
    // console.log('fetching: ' + url)
    res.setEncoding('utf8');
    res.pipe(concat({encoding: 'string'}, function(data) {
      callback(null, vm.runInThisContext(data));
    }));
  })
}

urls = [
  'http://example.com/nodejsmodules/myModule1.js',
  'http://example.com/nodejsmodules/myModule2.js',
  'http://example.com/nodejsmodules/myModule3.js',
]

async.map(urls, http_require, function(err, results) {
  // `results` is an array of values returned by `runInThisContext`
  // the rest of your program logic
});

You can fetch module using http.get method and execute it in the sandbox using vm module methods runInThisContext and runInNewContext.

Example

var http = require('http')
  , vm = require('vm')
  , concat = require('concat-stream'); // this is just a helper to receive the
                                       // http payload in a single callback
                                       // see https://www.npmjs.com/package/concat-stream

http.get({
    host: 'example.com', 
    port: 80, 
    path: '/hello.js'
  }, 
  function(res) {
    res.setEncoding('utf8');
    res.pipe(concat({ encoding: 'string' }, function(remoteSrc) {
      vm.runInThisContext(remoteSrc, 'remote_modules/hello.js');
    }));
});

IMO, execution of the remote code inside server application runtime may be reasonable in the case without alternatives. And only if you trust to the remote service and the network between.

0 dependency version (node 6+ required, you can simply change it back to ES5)

const http = require('http'), vm = require('vm');

['http://example.com/nodejsmodules/myModule.js'].forEach(url => {
    http.get(url, res => {
        if (res.statusCode === 200 && /\/javascript/.test(res.headers['content-type'])) {
            let rawData = '';
            res.setEncoding('utf8');
            res.on('data', chunk => { rawData += chunk; });
            res.on('end', () => { vm.runInThisContext(rawData, url); });
        }
    });
});

It is still the asynchronous version, if sync load is the case, a sync http request module for example should be required