Bug 2121665

Internet lore says we need to disable packagekit temporarily, like this, probably before wait-online succeeds:

systemctl stop packagekit
systemctl mask packagekit

then undo it at the end with

systemctl unmask packagekit
systemctl start packagekit

(dependent on its original status I guess)

Is masking the service actually needed?  Seems extreme ...

There's a danger with masking the service that users might not realise how
to turn it back on (since stopping < disabling < masking).

I think masking may be suggested because packagekit could have triggers other than just "systemctl start". I think someone from QE suggested that it was network activation that triggered packagekit specifically. My own experience (with different packages/services, such sa NFS) is that socket (?) activation can only be prevented with masking, not with "systemctl disable".

Either way, my idea here would be similar to what we do for SELinux at first boot -- first save the current state, then disable the service, then restore the original state. I hope we can get systemctl to tell us whether packagekit is currently masked, in machine-readable format.

Another complication is: what happens if packagekit is already running (or running a transaction) by the time we try to stop it? We might not be able to stop it (and if we do stop it, does it corrupt the transaction)? That's why I thought we should disable / mask packagekit before waiting for network connectivity.

I doubt we can ever make this robust :/

(1) check whether packagekit is running:

# systemctl is-active packagekit

Exits with status 0 and prints "active" if packagekit is running. Exits with nonzero status and prints "inactive" otherwise.

Save the output in a file.

(2) check whether packagekit is currently masked or not (we don't care about any other enablement status, just masked or not masked).

# systemctl is-enabled packagekit

The systemctl manual lists a bunch of possible enablement states, we only care about "masked" and "masked-runtime".

Save the output in a file.

(3a) If packagekit was masked in (2), then stop the service.

# systemctl stop packagekit

(3b) If packagekit was not masked in (2), then mask and stop the service.

# systemctl mask --now packagekit

(4) Install the guest agent.

(5) If packagekit was not masked in (2), then unmask the service.

# systemctl unmask packagekit

(6) If packagekit was running in (1), then start it.

# systemctl start packagekit


Now, whether stopping the packagekit service will actually stop a running transaction (or wait for the running transaction to complete) is anyone's guess.

I've also checked the zypper source code (@ 281f866999fc, "changes 1.14.56", 2022-09-02). When it asks the user about waiting for the concurrent packagekit transaction to complete, the default answer is "no", and in non-interactive mode, zypper *only* takes the default answer. There is no way to say "don't ask the user, just go ahead and answer "yes". The manual says as much, but I was incredulous, and checked the source code. The manual is factual.

Interestingly, the global "-n" (--non-interactive) option is the one we already use. There is also a command-specific (such as "install"-specific) option "-y" (--no-confirm). However, the manual does not recommend using "-y", and much more importantly, the source code handles "-y" by simulating "-n": "-y" does not change the default answer, it just enters non-interactive mode.