如何重定向到 www. Heroku 上我的 Flask 网站的版本？

Question

I've got a Python Flask app running on Heroku (Cedar stack) with two custom domains (one with and one without the www subdomain). I'd like to redirect all incoming requests to the www. version of the resource requested (the inverse of this question<\/a> ). I think I need some WSGI middleware for this but I can't find a good example.

Answer 1

An easier solution than to create a separate Heroku app would be a before_request function.

from urlparse import urlparse, urlunparse

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

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

Answer 2

According to the Heroku Docs, you've got the right idea about using the www subdomain (eg www.foo.com) vs apex domain (eg foo.com). Their suggestion for dealing with this is to use a DNS layer redirect:

To quote:

Subdomain redirection

Subdomain redirection results in a 301 permanent redirect to the specified subdomain for all requests to the apex domain so all current and future requests are properly routed and the full www hostname is displayed in the user's location field.

Almost all DNS providers offer domain redirection services - sometimes also called domain forwarding. DNSimple provides a convenient URL redirect seen here redirecting from the heroku-sslendpoint.com apex domain to the www.heroku-sslendpoint.com subdomain.

Source: http://devcenter.heroku.com/articles/avoiding-apex-domains-dns-arecords#subdomain_redirection

Hope that helps!

Answer 3

One possible approach would be to add a function to listen on request_started , and do the appropriate redirection.

This signal is sent before any request processing started but when the request context was set up. Because the request context is already bound, the subscriber can access the request with the standard global proxies such as request.

Answer 4

我最终做的是创建第二个Heroku应用程序，将非www主机名分配给该主机并使用catch所有Flask路由重定向到www版本，保持路径不变。

Answer 5

Try this. 

@app.route('/', methods=['GET', 'POST'], subdomain="www")
@app.route('/<string:path>', methods=['GET', 'POST'], subdomain="www")
def www(path=''):
    return redirect(url_for('app.index')+path)