Handle ACPI events

    acpid

    Beginning with Flatcar major release 3255 acpid can be enabled at boot with Ignition.

    This can be configured with a butane definition:

    ---
    variant: flatcar
    version: 1.0.0
    systemd:
      units:
        - name: acpid.service
          enabled: true
    storage:
      files:
        - path: /etc/acpi/events/default
          contents:
            inline: |
              event=.*
              action=/etc/acpi/default.sh %e          
    
        - path: /etc/acpi/default.sh
          contents:
            inline: |
              set $*
              logger "ACPI event handled: $*"          
          mode: 0744
    

    This simple configuration will only log the handled ACPI events, example with QEMU:

    butane < config.yml > ignition.json
    ./flatcar_production_qemu.sh -i ./ignition.json -- -qmp tcp:localhost:4444,server,wait=off
    

    From another terminal, it’s possible to send a shutdown signal for example:

    telnet localhost 4444
    { "execute": "qmp_capabilities" }
    { "execute": "system_powerdown" }
    

    From the acpid logs, it’s possible to see the logger in action:

    $ journalctl --unit acpid.service
    May 24 14:29:36 localhost systemd[1]: Started ACPI event daemon.
    May 24 14:29:36 localhost acpid[928]: starting up with netlink and the input layer
    May 24 14:29:36 localhost acpid[928]: 1 rule loaded
    May 24 14:29:36 localhost acpid[928]: waiting for events: event logging is off
    May 24 14:30:20 localhost root[1041]: ACPI event handled: button/power PBTN 00000080 00000000
    May 24 14:30:20 localhost systemd[1]: Stopping ACPI event daemon...
    May 24 14:30:20 localhost acpid[928]: exiting
    May 24 14:30:20 localhost systemd[1]: acpid.service: Deactivated successfully.
    May 24 14:30:20 localhost systemd[1]: Stopped ACPI event daemon.