@d19dotca I think the -f flag on install just "cleans up" the installation : it notices that some files required for some packages were removed (in the previous line), so it removes said packages. What actually frees up the space is the rm. The apt-get -f install just makes the system notice that the packages in question are not installed anymore
Ah we did hit that kernel/initramfs issue with /boot getting filled up by Ubuntu already before. If it is 100% full even the autoremove fails.
Would be good to actually not just maybe warn about that, but see how the whole situation can be mitigated in the first place. Afterall it is not much use to have that many kernel versions around.
As @scooke and @mehdi already mentioned, the sole reason to support only one distribution is the reduced complexity by having to deal with only a single well known system. Even different ubuntu versions require quite a lot of testing and different code. Sometimes package names change for example. We essentially just settled on Ubuntu 16.04 initially since that was available on basically every VPS provider. Really that is the main concern for us. Naturally for security updates we then progressed to 18.04 and will soon hopefully support 20.04. Other distros with even other package managers are simply just overhead and cause trouble to users. In the end from what Cloudron requires, there will hardly be any noticeable difference in speed or resources use between any of the distros, so we lean towards stability here.