12.9. Automatically updating containers using systemd

Procedure

1. Display the podman-auto-update.service unit file:

   # cat /usr/lib/systemd/system/podman-auto-update.service
   
   [Unit]
   Description=Podman auto-update service
   Documentation=man:podman-auto-update(1)
   Wants=network.target
   After=network-online.target
   
   [Service]
   Type=oneshot
   ExecStart=/usr/bin/podman auto-update
   
   [Install]
   WantedBy=multi-user.target default.target

2. Display the podman-auto-update.timer unit file:

   # cat /usr/lib/systemd/system/podman-auto-update.timer
   
   [Unit]
   Description=Podman auto-update timer
   
   [Timer]
   OnCalendar=daily
   Persistent=true
   
   [Install]
   WantedBy=timers.target

   In this example, the podman auto-update command is launched daily at midnight.

3. Enable the podman-auto-update.timer service at system start:

   # systemctl enable podman-auto-update.timer

4. Start the systemd service:

   # systemctl start podman-auto-update.timer

5. Optional: List all timers:

   # systemctl list-timers --all
   NEXT                         LEFT      LAST                         PASSED       UNIT                         ACTIVATES
   Wed 2020-12-09 00:00:00 CET  9h left   n/a                          n/a          podman-auto-update.timer     podman-auto-update.service

   You can see that podman-auto-update.timer activates the podman-auto-update.service.