Enable podman-auto-update.timer in Wiki?

[Klaaktu]

The wiki says:

Additional benefit is that this method will keep the container updated.

However, from podman-systemd.unit, it seems that AutoUpdate=registry + Image=... only means that you can do podman auto-update. To auto update as in unattended, podman-auto-update.timer needs to be enabled.

So the wiki could suggest either sudo podman auto-update once in a while or sudo systemctl enable podman-auto-update.timer.

p.s. I remember somewhere said that daemon-reload/reboot would trigger image update, but it doesn't seem to be true for me.

[Arcitec]

You are correct.

• Enabling AutoUpdate= does nothing by itself. It's just a marker to let Podman know that you want to include that container in the auto-update processing.
• podman auto-update is the actual command that checks and installs updates. You can run it manually anytime if you want.
• podman-auto-update.service is a "oneshot service" which just runs podman auto-update followed by podman image prune -f and then immediately exits itself. Enabling this "service" makes no sense and you should never do it!
• podman-auto-update.timer is an actual timer which triggers podman-auto-update.service every day. That is the correct thing to enable.
• To enable it for root: sudo systemctl enable --now podman-auto-update.timer
• Or if you run the container as a rootless user, enable it for the user with: systemctl --user enable --now podman-auto-update.timer
• The default timer behavior is to run at a slightly randomized time (within 15 minutes) after midnight every day. If you miss the timer date, Systemd timers will instead run the next time your computer boots/wakes up, so you never have to worry about "missing the timer".
• You can also edit the timer interval with the following commands:
• Editing timer for root: sudo systemctl edit podman-auto-update.timer
• Editing timer for user: systemctl --user edit podman-auto-update.timer
• Editing timers is complicated, but there's a helpful article and systemd.timer man page.
• If you want to see the root logs for the last time the auto-update service ran (doesn't include manual runs): journalctl -xeu podman-auto-update
• Or the same thing for user's rootless service instead: journalctl --user -xeu podman-auto-update
• Important: If the container fails to start after an image auto-update, then it will automatically be rolled back to the last working image version. This happens during podman auto-update itself, since that command is responsible for starting the server again. If it sees that the service cannot start, then it rolls back the changes. See the documentation for more details. You can ignore the documentation's notes about --sdnotify, since everything is already configured properly if you've used Podman Quadlets to set up the Systemd service.

PS: "daemon-reload" and other commands do not update the image. It doesn't even matter if you have a newer version of that image on disk already. The only thing that updates a container to use a newer version of an image is the podman auto-update task.