This took a whole lot of experimentation. I hit upon the idea
of doing a `systemctl stop sshd` to avoid the situation where we
might ssh back into the system while it's in the process of shutting
down.
Ultimately the other fix is disabling `ControlMaster`; see
for example: https://github.com/ansible/ansible/issues/17935Closes: #1548
Approved by: cgwalters
Add API to write a deployment state to `/run/ostree/staged-deployment`,
along with a systemd service which runs at shutdown time.
This is a big change to the ostree model for hosts,
but it closes a longstanding set of bugs; many, many people have
hit the "losing changes in /etc" problem. It also avoids
the other problem of racing with programs that modify `/etc`
such as LVM backups:
https://bugzilla.redhat.com/show_bug.cgi?id=1365297
We need this in particular to go to a full-on model for
automatically updated host systems where (like a dual-partition model)
everything is fully prepared and the reboot can be taken
asynchronously.
Closes: https://github.com/ostreedev/ostree/issues/545Closes: #1503
Approved by: jlebon
Colin Walters