RedirectRegex broken since update to v3.0

[lazka]

Welcome!

• Yes, I've searched similar issues on GitHub and didn't find any.
• Yes, I've searched similar issues on the Traefik community forum and didn't find any.

What did you do?

I have the following RedirectRegex config: https://github.com/msys2/msys2-main-server/blob/8330fd44f4fdf76d27200e995fb8494a4006e6c3/docker-compose.yml#L153-L154

This resulted in "https://mingw-w64.org" being redirected to "https://www.mingw-w64.org", among other cases.

Since the update to v3.0 from v2.11.2 this no longer works and requests using "https://mingw-w64.org" no longer get redirected. I've confirmed that downgrading to 2.11 makes things work again.

I couldn't find anything in the migration guide regarding any changes for RedirectRegex, so I'm filing this here.

What did you see instead?

No redirect happening.

What version of Traefik are you using?

3.0.0

What is your environment & configuration?

See the linked docker-compose.yml above

If applicable, please paste the log output in DEBUG level

No response

[pbek]

I have the same issue after migrating from Traefik v2 to Traefik 3.0, e.g. also with a simple redirect from www.mydomain to mydomain.

Config:

      - traefik.http.middlewares.bekerle-web-2022-www.redirectregex.regex=^(https?://)www.(.*)$$
      - traefik.http.middlewares.bekerle-web-2022-www.redirectregex.replacement=$${1}$${2}
      - traefik.http.middlewares.bekerle-web-2022-www.redirectregex.permanent=true

There was no redirect, the webpage could not be accessed anymore.

There were no docker logs for the traefik container.

[pbek]

But what did work on Traefik v3 was:

      - traefik.http.middlewares.nextcloud-redirectregex.redirectregex.permanent=true
      - traefik.http.middlewares.nextcloud-redirectregex.redirectregex.regex=^https://(.*)/.well-known/(card|cal)dav
      - traefik.http.middlewares.nextcloud-redirectregex.redirectregex.replacement=https://$${1}/remote.php/dav/