Is it possible to set a base URL for NodeJS app?

Question

I want to be able to host multiple NodeJS apps under the same domain, without using sub-domains (like google.com/reader instead of images.google.com). The problem is that I\

Answer 1

At the moment this is not supported, and it's not easy to add it on your own.

The whole routing stuff is buried deep inside the server code, and as a bonus there's no exposure of the routes them selfs.

I dug through the source and also checked out the latest version of Express and the Connect middleware, but there's still no support for such functionality, you should open a issue either on Connect or Express itself.

Meanwhile...

Patch the thing yourself, here's a quick and easy way with only one line of code changed.

In ~/.local/lib/node/.npm/express/1.0.0/package/lib/express/servers.js, search for:

// Generate the route
this.routes[method](path, fn);

This should be around line 357, replace that with:

// Generate the route
this.routes[method](((self.settings.base || '') + path), fn);

Now just add the setting:

app.set('base', '/myapp');

This works fine with paths that are plain strings, for RegEx support you will have to hack around in the router middleware yourself, better file an issue in that case.

As far as the static provider goes, just add in /mypapp when setting it up.

Update

Made it work with RegExp too:

// replace
this.routes[method](baseRoute(self.settings.base || '', path), fn);

// helper
function baseRoute(base, path) {
    if (path instanceof RegExp) {
        var exp = RegExp(path).toString().slice(1, -1);
        return new RegExp(exp[0] === '^' ? '^' + base + exp.substring(1) : base + exp);

    } else {
        return (base || '') + path;
    }
}

I only tested this with a handful of expressions, so this isn't 100% tested but in theory it should work.

Update 2

Filed an issue with the patch:
https://github.com/visionmedia/express/issues/issue/478