如何将包含以“www”开头的URL的所有请求重定向到裸域？

Question

I have been successful in adding Heroku custom domains for my app. I'd like to know how to capture requests that begin with www and redirect them to the naked domain. For example, I have the following custom domains mapped to my Heroku app:

www.myapp.com
myapp.com

Requests for http://myapp.com and http://www.myapp.com are both successful, but the www stays on.

Objective

I want all requests for http://www.myapp.com to be redirected to http://myapp.com . This should also work for other paths, like http://www.myapp.com/some/foo/bar/path redirects to http://myapp.com/some/foo/bar/path . I want something like this: http://www.stef.io and see how the www. is gone from the address bar.

The instructions I've found on Google so far are about editing my .htaccess file, but I'm running on Heroku with a Python app on the Flask framework.

Answer 1

The recommended solution for this is DNS level redirection (see heroku help ).

Alternatively, you could register a before_request function:

from urlparse import urlparse, urlunparse

@app.before_request
def redirect_www():
    """Redirect www requests to non-www."""
    urlparts = urlparse(request.url)
    if urlparts.netloc == 'www.stef.io':
        urlparts_list = list(urlparts)
        urlparts_list[1] = 'stef.io'
        return redirect(urlunparse(urlparts_list), code=301)

This will redirect all www requests to non-www using a "HTTP 301 Moved Permanently" response.

Answer 2

I'm not used to Flask, but you could set up a route that matches /^www./ and then redirect it to the url without the "www".

You may want to check http://werkzeug.pocoo.org/docs/routing/#custom-converters or http://werkzeug.pocoo.org/docs/routing/#host-matching