Ask HN: Help re-finding a self hosting platform with decent SSO support

With a friend we've been working on a project to do some self hosting in such a way as to support a few local community groups move into their own hosted tech (Nextcloud etc).

While we're very aware of "self hosting platforms" like yunohost.org, we've been wanting to use a platform that supports Docker and has a decent 'marketplace' of self hosted software already supported.

In the last few months I found an excellent open source self hosting platform, but can't for the life of me find it now. Hoping some smart person reading this will be like, "Oh you mean this project <inserts project name>".

From memory the self hosted platform had these features:

- Good SSO support (more below)

- Open Source and free for self hosting

- Good marketplace of listed apps

- Sat on top of docker, allowing new apps to be added to the marketplace OR just loaded by linking to the url for the docker-compose file.

- Had it's own .yml configuraton format (that also supported .json), which elegantly resolved how to configure SSO.

- Pretty sure it was built with python and you started by running a python script.

My eternal gratitude if you can name and link to the project.

It's NOT any of these:

- https://coopcloud.tech

- https://cosmos-cloud.io

- https://cloudron.io

- https://caprover.com

- https://yunohost.org