flask.redirect does not work as expected behind reverse proxy

[nicodravis]

Hello folks,

I have the following setup - serving with Waitress (http) behind an IIS reverse proxy for SSL/TLS support. Once I enabled the reverse proxy, the redirect function started appending all redirects to the proxied URL. The proxied URL is the VM host name (servername) at default ports 80/443, channeling requests to another port.

The issue is that when using the redirect function, instead of getting a redirect for (https://login.microsoftonline.com)/tenant.. I am getting a "proxied redirect" for my proxied URL - servername/tenant.., and this is happening for all redirects. If I put a redirect('www.github.com'), it redirects to servername/www.github.com.

Any thoughts here how I can overcome this?

Best, Nico

[rayluo]

If I put a redirect('www.github.com'), it redirects to servername/www.github.com.

This is clearly outside of the scope of this sample which specializes in authentication.

You shall create a new issue in Flask repo, asking that redirect('www.github.com') question only. Do not mention anything about "login.microsoftonline.com", as it would be a red-herring for your case.

[nicodravis]

Hi Ray, Thanks for your response, I am taking a note on that. While I wanted to illustrate the behaviour change once the reverse proxy was enabled, I realize the examples I provided might have been misleading. As you're tackling the reverse proxy scenario using redirects, I presumed I could ask where I might be getting things wrong with the sample as instead of getting a proper logout redirect URL, I started receiving the proxied URL instead of the AUTHORITY one followed by the tenant id and remaining URL parts.

Thanks for your comments.

[rayluo]

I mean, based on what you described, you could probably reproduce the issue with only these lines plus this:

@app.route("/")
def index():
    return redirect("the content you chose")

At that point it would be a Flask usage question, wouldn't it?