Layouts: re-mapping snap directories

I’d like to give everyone an update on where we are with this feature:

I’m working on two base features:

  • simple creation of target / source directories for mounts / bind mounts (PR 4008)
  • control of mode and ownership of created directories (PR 3965)
  • generalized creation of directories on top of read-only filesystems using overlayfs (Git branch)

The most interesting one is the last one, I will open the PR soon but I’m still working on the undo logic and I want the prerequisite 4008 to land first. Once we have it open we need to examine how viable that is and if poses any security risks. I must say I’m really fond of this approach as it has the potential to simplify everything tremendously and is very elegant on the inside and at runtime.

After this I’d like to explore content interface to update it to the new specification. Using this set of features we should be able to easily create aggregation directories. In parallel we can start exploring using the layout work as all that would be missing is better definition of what is allowed and not allowed and connecting the layout specification with the existing mount backend.