The web interface runs headless, so every privileged systemctl call must be
covered by a NOPASSWD rule in /etc/sudoers.d/ledmatrix_web. The sudo command
matches the command line exactly, but the code called 'systemctl start
ledmatrix' while configure_web_sudo.sh grants 'systemctl start
ledmatrix.service'. The rule never matched, so start/stop/enable/disable/
restart fell back to a password prompt and failed with 'a terminal is
required to read the password'.
Align all privileged systemctl calls on the fully-qualified unit names the
sudoers grants use. Add a regression test that cross-checks api_v3.py calls
against the grants in configure_web_sudo.sh.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
