Add podman-restart systemd unit file

[boaz0]

closes #10539
closes #9579

[vrothberg]

Code LGTM.

Any chance we could test the podman-restart.service in CI?

A simple test with podman create --restart=always --name foo, followed by a systemctl start podman-restart.service and then making sure foo is running should work (tested locally).

@lsm5 @jnovy PTAL for the packaging parts. Is there a way to enable the service by default in rpm?

[edsantiago]

Any chance we could test the podman-restart.service in CI?

Not trivially, but it's doable. One will need to hand-copy the service file into the systemd directory, daemon-reload, etc etc. See test/system/2[57]*.bats for examples.

[boaz0]

Now going to work on the tests for the unit file.

[rhatdan]

I am fine with getting this in without tests, for now. We can open a separate PR for tests. Would like to get this out to the world to test, since it has been requested for some time.

[nanonyme]

Should this not require network or whatnot though? Or what makes this be scheduled late enough that started things won't immediately break?

[rhatdan]

Good point, it should probably be

[Install]
WantedBy=multi-user.target

We should add this to podman.service and add

[Install]
WantedBy=sockets.target

to podman.socket

[TomSweeneyRedHat]

LGTM
once @rhatdan 's thoughts are addressed.

[boaz0]

DONE @rhatdan @TomSweeneyRedHat

[TomSweeneyRedHat]

LGTM

[rhatdan]

/lgtm
Thanks @boaz0

[rhatdan]

/approve

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: boaz0, rhatdan

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [rhatdan]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[Aposhian]

Pardon if this is an ignorant comment, but doesn't adding

WantedBy=multi-user.target

to podman.service effectly make podman no longer "daemonless" as is commonly touted, if you compile with the systemd feature?

[vrothberg]

As long as no other service "Requires" podman.service, it won't be started at boot. In the worst case of it being started at boot, it would shut down quickly when no incoming REST calls are detected.

[rhatdan]

@Aposhian Podman does not require a long running daemon to run. If apps like docker compose or docker-py or podman-py want to talk to a restapi to launch a service. We added options to podman system service to be able to service this API.

Podman will act as a socket activated service to launch containers for the API. You can run multiple of these services if you wanted to, and it runs rootless and rootfull. The service goes down within 5 seconds of the last connection. If you want to call this a daemon, then fine.
But that does not change the fact that Podman does not require a Daemon.