2038027 - Add http://detectportal.firefox.com/generate_204

Status: RESOLVED FIXED

(Cloud Services :: Operations: Miscellaneous, task)

Description

[Valentin Gosu [:valentin]]

We know that some captive portal implementations do not work nicely with our canonical.html implementation, but work with Chrome's generate_204 endpoint.
We should set up a similar endpoint for our detectportal domain, that works in a similar way.

curl http://www.gstatic.com/generate_204 -v
* Host www.gstatic.com:80 was resolved.
* IPv6: 2607:f8b0:4023:1803::5e
* IPv4: 142.250.137.94
*   Trying [2607:f8b0:4023:1803::5e]:80...
* Connected to www.gstatic.com (2607:f8b0:4023:1803::5e) port 80
* using HTTP/1.x
> GET /generate_204 HTTP/1.1
> Host: www.gstatic.com
> User-Agent: curl/8.14.1
> Accept: */*
> 
* Request completely sent off
< HTTP/1.1 204 No Content
< Content-Length: 0
< Cross-Origin-Resource-Policy: cross-origin
< Date: Thu, 07 May 2026 20:04:56 GMT
< 
* Connection #0 to host www.gstatic.com left intact

So it should at least return status 204, and headers of Content-Length: 0.

Comment 1

[Valentin Gosu [:valentin]]

Hi Jon, maybe you can help us with this?
It's not super urgent, but I just wanted to make sure this is on someone's radar.

Comment 2

[Jon Buckley [:jbuck]]

:rmuller was working on migrating detect portal to Fastly and added this path to his PR: https://github.com/mozilla/webservices-infra/pull/11100

Comment 3

[Jon Buckley [:jbuck]]

And the ticket itself is https://mozilla-hub.atlassian.net/browse/MZCLD-2973

Comment 4

[:wezhou]

:valentin We've set up a test domain, http://detectportal-fastly.firefox.com/, with the requested feature enabled (see http://detectportal-fastly.firefox.com/generate_204).

Could you give it a try and let us know whether it behaves as expected? Once it's validated, we can enable it as part of the detectportal CDN migration to Fastly.

Comment 5

[Valentin Gosu [:valentin]]

Hi Robert - I can confirm the endpoint works as expected. Looking forward to seeing it deployed. Thanks!

Comment 6

[Jon Buckley [:jbuck]]

We've migrated detectportal.firefox.com to Fastly, so this endpoint is available to use for all clients now