I finally took a leap of faith and installed Authentik to centralize authentication for my self-hosted services.
Among those services, there is of course Apache Guacamole, which allows me to remotely access my servers and computers. Once the guacamole-auth-sso-openid extension installed and configured, I go back to the Guacamole's login page, and honestly, it is quite ugly out of the box (no offense, I love the tool, but the graphics are what they are...), but the location of the SSO links, at the bottom left corner adds a bit of ugliness. A small cristal of pee on a cake of shit....
So I tried what I never dared to do earlier, and I wrote an extension to change this appearance. And I find it quite stylish (compared to what it was before!)

The screenshot shows all sso methods, but in practice, only the sso extensions you configured will be shown. In my case, only "OpenId Connect" is present.
Code is of course available and open-source. I have not selected a licence yet, because let's face it, the probability of it being forked and used is veeeeeeeeeeeeeeeeeeery low. If I chose a licence one day, it will probably be Apache 2.0, because that's Guacamole's license.
Oh, and by the way, this extension is shipped with my Guacamole Docker image, you just need to enable it in your docker-compose ordocker run command.
@+