Can I upgrade UCS or Apps from within the Docker container?
No, this should not be done nor should it be possible. Always use the UCS host mechanism (UMC, univention-app) to update your app.
UCS Docker Image
Some apps use internally a UCS Docker image in version 4.3 to acquire compatibility. So as additional layer they use UCS 4.3 while the host itself is already upgraded to UCS 4.4 for example.
With a new version of the app the underlying UCS Docker might be updated. However, this is something which has not to be done manually (and should not be possible, too).
- UCS host: Update your host as usually through UMC or univention-upgrade
- UCS container: The internal UCS 4.3 has a scheduler configured which installs security fixes automatically.
- App: Use default ways (see UCS host)
So it is expected behaviour to see the Docker container running on UCS 4.3 while the Docker host runs as 4.4.