Auto-Update and Auto-Reboot

cache22 ships two independent helpers for unattended updates:

  • cache22-autoupdate schedules cache22-update on a systemd timer. It fetches and stages updates. It never reboots.
  • cache22-autoreboot schedules a reboot window. At each firing it checks whether a staged update is ready and reboots if conditions are met.

Both are opt-in. Neither is enabled by default.

The split is intentional: staging is safe to do at any time. Rebooting is a stateful operation that should respect active sessions and time-of-day preferences.

cache22-autoupdate

Synopsis 

sudo cache22-autoupdate enable [--profile PROFILE] [--schedule SPEC] [--no-app-updates]
sudo cache22-autoupdate disable
sudo cache22-autoupdate status

Profiles

Two named profiles are picked automatically based on whether the system’s default-target is graphical or multi-user:

Profile Trigger
default-desktop 1 hour after boot, then daily after each firing.
default-server OnCalendar=daily (00:00 UTC) + 2-hour random delay.

Both profiles have Persistent=true (catches missed firings after sleep or shutdown) and Restart=on-failure RestartSec=60s with 3 retries (handles cases where the network is not yet up at wake).

Examples

Enable with the auto-picked profile:

sudo cache22-autoupdate enable

Force a specific profile:

sudo cache22-autoupdate enable --profile default-server

Use a custom OnCalendar value:

sudo cache22-autoupdate enable --schedule '*-*-* 03:00'    # Every day at 03:00 local time.
sudo cache22-autoupdate enable --schedule weekly            # Weekly.
sudo cache22-autoupdate enable --schedule 'Mon *-*-* 04:00' # Mondays at 04:00.

Disable app updates (OS only):

sudo cache22-autoupdate enable --no-app-updates

Check current state:

sudo cache22-autoupdate status

Output shows the active profile or schedule, when the timer last fired, when it next fires, and the result of the last update.

Disable entirely:

sudo cache22-autoupdate disable

Configuration files

cache22-autoupdate enable writes:

  • /etc/cache22/autoupdate.conf containing APP_UPDATES=yes|no.
  • /etc/systemd/system/cache22-autoupdate.timer.d/cache22.conf containing the OnCalendar= and RandomizedDelaySec= overrides.

To edit by hand, modify the files and run sudo systemctl daemon-reload followed by sudo systemctl restart cache22-autoupdate.timer.

cache22-autoreboot

Synopsis 

sudo cache22-autoreboot enable --at SPEC [--window DURATION] [--allow-active-sessions]
sudo cache22-autoreboot disable
sudo cache22-autoreboot status

Conditions for reboot

When the timer fires, the helper polls for these conditions:

  1. A staged deploy exists (bootc status .status.staged != null).
  2. The most recent cache22-autoupdate.service run did not fail.
  3. No active sessions are blocking, unless --allow-active-sessions was set.

If all three are satisfied, the helper broadcasts a 5-minute warning to logged-in users (via wall) and then calls cache22-reboot. The strategy is selected by cache22-reboot’s auto-pick logic, which reads /etc/cache22/reboot.conf.

If a session blocks the reboot, the helper polls again at POLL_INTERVAL (default 60 sec) until the window expires. If the window expires with sessions still active, the helper exits and waits for the next OnCalendar firing.

Examples

Reboot every day at 04:00 if a staged update is ready:

sudo cache22-autoreboot enable --at 'daily 04:00'

Note: systemd’s calendar grammar does not accept daily 04:00 as a single token in all versions. Equivalent forms that always work:

sudo cache22-autoreboot enable --at '04:00'
sudo cache22-autoreboot enable --at '*-*-* 04:00:00'

Sundays only at 03:00:

sudo cache22-autoreboot enable --at 'Sun *-*-* 03:00:00'

Tuesdays and Saturdays at 16:00 with a one-hour window for sessions to end:

sudo cache22-autoreboot enable --at 'Tue,Sat *-*-* 16:00:00' --window 1h

Always reboot, even with active sessions:

sudo cache22-autoreboot enable --at '04:00' --allow-active-sessions

Check the current state:

sudo cache22-autoreboot status

Disable entirely:

sudo cache22-autoreboot disable

Configuration files

cache22-autoreboot enable writes:

  • /etc/cache22/autoreboot.conf containing WINDOW= and ALLOW_ACTIVE_SESSIONS=.
  • /etc/systemd/system/cache22-autoreboot.timer.d/cache22.conf containing the OnCalendar= override.

The reboot strategy itself (soft, kexec, hard) is read from /etc/cache22/reboot.conf at reboot time. cache22-autoreboot does not own that setting.

Combined daily update + reboot

A common configuration: fetch updates at 05:00, reboot at 05:30 if anything is staged.

sudo cache22-autoupdate enable --schedule '05:00' --no-app-updates
sudo cache22-autoreboot enable --at '05:30' --window 30m

The 30-minute gap gives the autoupdate run time to complete (typical fetch + stage is 1-3 minutes; the gap is large because flaky networks can stretch it). The window lets autoreboot retry through the half-hour if a session is briefly active.

To use kexec for kernel-changing updates in this configuration:

echo 'KERNEL_CHANGE_STRATEGY=kexec' | sudo tee -a /etc/cache22/reboot.conf

If the system uses LUKS+TPM, also enroll a PCR 7 keyslot so kexec auto-unlocks. See TPM and LUKS.

Alternative: bootc’s own timer

The upstream bootc package ships its own fetch-apply timer:

sudo systemctl enable --now bootc-fetch-apply-updates.timer

Same fetch + stage behavior. It does not run flatpak or distrobox updates, does not refresh the cache22 pending-reboot banner, and does not compose with cache22-autoreboot for window-based reboots (it calls bootc upgrade --apply directly).

Use the bootc timer if cache22-autoupdate’s profile or scheduling layer is not wanted.

See also