Allow custom web interface URI for Pi-hole admin

[pepramon]

Overview

This pull request adds support for a configurable web interface URI in the Pi-hole Docker container. With this update, users can specify where the Pi-hole admin interface is served by setting the environment variable FTLCONF_webserver_paths_webhome.

Motivation

In many deployment scenarios—especially those using a reverse proxy for HTTPS—it is beneficial to serve the admin interface under a custom URI. For example, by setting FTLCONF_webserver_paths_webhome=/pihole/ in your docker-compose file, the admin interface will be available at /pihole/ instead of the default /admin/.

How to Enable

To activate this feature, add the following line to your docker-compose file:

FTLCONF_webserver_paths_webhome=/pihole/

This instructs the container to serve the admin interface from the specified path.

Testing

Please test the change in your environment by defining the variable and verifying that the Pi-hole admin interface is correctly accessible from the new URI.

Conclusion

This update provides enhanced flexibility for configuring the Pi-hole Docker container, making it easier to integrate with custom routing or proxy setups.

[yubiuser]

This might work in docker already, but on bare metal this won't work as we (unfortunately) have some hard-coded paths in various scripts.

[rdwebdesign]

I don't think this will work in docker without other modifications.

I think the pihole updatechecker function (used to search for updates) uses the hard-coded path for git commands.

[pepramon]

I tested it and it works for a Docker image without problems.

You can enter the container using docker exec -it pihole /bin/bash and try moving the path. This approach does not work and the web interface loads incorrectly; you need to change FTLCONF_webserver_paths_webhome for it to work correctly.

I do not know how pihole updatechecker works, but in a Docker approach, I do not update via Git or script; I just update the image, and that's all. However, if you use pihole updatechecker before moving the path, it will probably work correctly because when the Docker image starts, the main path is /admin/ and you move it after the update is done.

I do not know how updatechecker works or when it is triggered, and I have tried to review those aspects.

[rdwebdesign]

I do not know how pihole updatechecker works

It uses git to compare the local and remote branches.

These lines won't work if the web interface is moved:

https://github.com/pi-hole/pi-hole/blob/567bb724b18bf174f033d0b8b289cc44a5e9c8eb/advanced/Scripts/updatecheck.sh#L88-L95

Without updatechecker, the container will fail to find the current local version.

[pepramon]

I just added a little dirty trick:

Just add a symlink to the admin directory so that other scripts can work properly. However, it is necessary to set FTLCONF_webserver_paths_webhome because if it is not set, the admin page does not work properly.

[rdwebdesign]

I really think this should be fixed on Core as well before any release, so every installation (docker and bare metal) will allow this option.

And when we change Core code, some changes made here will need to be adjusted, some will be unnecessary.

[PromoFaux]

No comment on inclusion validity at the moment, but from a technical standpoint:

The login page goes brrrrrrrrrrrrrrrrrrrrrrr. Which it probably shouldn't 😉

[rdwebdesign]

Looks like the page is redirecting to itself (/admin/login) or constantly reloading.

[PromoFaux]

I really think this should be fixed on Core as well before any release,

There are also some hardcoded admin/ paths in the web interface by the looks of things

[rdwebdesign]

And in FTL too:
https://github.com/pi-hole/FTL/blob/ac500d5f1ff192d087209d6e9b955515c8f35434/src/api/docs/content/index.html

[pepramon]

Oups, I do not detect that issue, my pihole is behind a nginx proxy, and seem that happens with SSL fail. Now I see

Later, when you enter (jut try to write and stops), seems that all works nice. It's only the login page.

I think that better option is remove this pull request because is harder than I think.

Sorry.