# A drive plugged in later.
#
# The panel's disc player follows the machine's hardware rather than a
# setting, so a USB drive connected after the room was set up has to be
# noticed. This re-runs the same detection the boot service runs; the
# button appears at the next login, because the panel is built at login
# and rewriting a running one destroys it — measured.
#
# --no-block so udev never waits for systemd, and a match narrow enough
# that nothing but an optical drive can trigger it.
ACTION=="add|remove", SUBSYSTEM=="block", ENV{ID_CDROM}=="1", \
    RUN+="/usr/bin/systemctl start --no-block ekklesia-classroom-layout.service"