“Missing support for abstract unix sockets (https://bugs.launchpad.net/snappy/+bug/1604967 )”
There is an open question on this in the bug. The last time I talked to Nicholas I was under the impression this was no longer needed. Also note new support for socket, socket-mode and listen stream (Snapcraft.yaml reference) that may help you in this area
“Needs SSH interface (https://bugs.launchpad.net/snappy/+bug/1606574 )”
This should be DONE (we now have both ssh-keys and ssh-publis-keys interfaces)
“Bash completion doesn’t work (https://launchpad.net/bugs/1612303 )”
This should be DONE. You might try looking into @chipaca’s excellent bash completion work: Tab completion for snaps
“Juju plugin support (https://bugs.launchpad.net/juju/+bug/1628538 )”
This doesn’t seem to be a snapd deficiency (please correct if I’m wrong). We now have a content interface (The content interface) that should allow the juju snap to ‘slot’ a read/write area and for plugins to ‘plug’ this slot and write data to it. How you organize it, do registration, etc is completely up to you
Can you verify the above and confirm if anything else is still needed?