Mac OS X上的Node.js出现错误“ Access-Control-Allow-Origin不允许原始http：// localhost”

Question

I recently bought my first Apple Mac (which is running Mavericks) on which I have installed node.js (of which I am also a novice).

I have run into an issue which hopefully someone will be able to provide me with a simple answer to. I am getting the error...

Origin http://localhost is not allowed by Access-Control-Allow-Origin .

I started the apache server, created a small html file called browser.html and placed it in /library/webserver/documents/

This allows me to view it at http://localhost/browser.html

This html file contains the following script…

$.ajax('http://127.0.0.1:8124/littletest.js', {
    success: function() {console.log('browser success')},
    error: function() {console.log('browser fail')}
});

I then created a file called littletest.js in the same folder as browser.html (I previously had it in /users/[my mac's user name]/test/ but moving made no difference to the problem)

The contents of the littletest.js file are…

var http = require('http');

http.createServer(function (req, res) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('Hello Node.js\n');
}).listen(8124, "127.0.0.1");

console.log('Server running at http://127.0.0.1:8124/');

By going to this folder in Terminal and entering node littletest.js the script starts.

But as mentioned above, when I browse to http://localhost/browser.html I get the error…

XMLHttpRequest cannot load http://127.0.0.1:8124/littletest.js. Origin http://localhost is not allowed by Access-Control-Allow-Origin.

I know this can be resolved by adding the following lines to the littletest.js file…

res.setHeader('Access-Control-Allow-Origin', 'http://localhost');
res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');
res.setHeader('Access-Control-Allow-Headers', 'Content-Type');

…but surely it isn't normal to have to do this every time, is it?!

Is this normal? (because it generally never mentions anything about this in any of the examples I've read).

Or is it that I am setting up my environment wrong? Please help!

Thanks for any assistance you can give because this has been perplexing me for some time now!

Answer 1

You're using 127.0.0.1:8124 in one place and localhost in another. You and I know that those are owned by the same person, but they look different to the browser, so the cross-origin access policies are enforced. If you just normalize on one of those (it shouldn't matter which you use, as long as you're consistent) the problem should be fixed. Note that this means both using the same domain ( 127.0.0.1 or localhost ) as well as using the same port.