audit 5: the supervisor socket the panel's alone, OpenDKIM logs and oversigns From

M17: the supervisord control socket is root:supervisor 0770, a group whose
one member is the panel; OpenDKIM and Postfix keep `selfpost` for the files
under /data and no longer reach the socket.

L30, read in OpenDKIM 2.11.0~beta2's source first: it logs through
syslog(3) only and has no Logfile option, and nothing in the container
served /dev/log. internal/syslogrelay (the panel binary with
-syslog-relay=/run/syslog/log, program syslog-relay before OpenDKIM,
/dev/log a link to its socket) passes the datagrams to stdout, error and
worse marked. opendkim.conf: Syslog yes, Canonicalization relaxed/simple,
OversignHeaders From (RFC 6376 § 3.4, § 8.15). e2e: OpenDKIM's start line
reaches the container log; every program RUNNING; DKIM verifies.

Tested on the test server: go vet + go test of 26 packages, make e2e (all
pass, 626 s) on this tree.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

build/supervisord.conf

@@ -26,17 +26,20 @@ logfile_maxbytes=0
 pidfile=/run/supervisord.pid
 loglevel=info
 
-; The control socket is reachable by the shared `selfpost` group so the panel
-; (running as the unprivileged `panel` user) can ask supervisord to send
-; OpenDKIM a reload signal after it rewrites the DKIM tables. It is still
-; unreachable by world; only root and the two SelfPost services are in the
-; group. No HTTP auth is configured because access is gated by socket
-; permissions, not the network. (supervisor 4.2.5, docs/configuration.rst,
-; [unix_http_server]: chmod and chown set the socket's mode and owner; without
-; username and password no authentication is asked.)
+; The control socket is reachable by the `supervisor` group, whose one member
+; is the panel (the unprivileged `panel` user): it asks supervisord to signal
+; OpenDKIM after it rewrites the DKIM tables, to run the Postfix reload, and
+; for the processes' state. Whoever reaches the socket can stop, start or
+; restart any program, so it is not the shared `selfpost` group's: OpenDKIM
+; and Postfix are in that one for the files under /data, and a fault in either
+; must not reach every other program (audit 2026-10-12, stage 5). Not
+; reachable by world. No HTTP auth is configured because access is gated by
+; socket permissions, not the network. (supervisor 4.2.5,
+; docs/configuration.rst, [unix_http_server]: chmod and chown set the socket's
+; mode and owner; without username and password no authentication is asked.)
 [unix_http_server]
 file=/run/supervisor.sock
-chown=root:selfpost
+chown=root:supervisor
 chmod=0770
 
 [rpcinterface:supervisor]
@@ -45,6 +48,23 @@ supervisor.rpcinterface_factory = supervisor.rpcinterface:make_main_rpcinterface
 [supervisorctl]
 serverurl=unix:///run/supervisor.sock
 
+; The container's /dev/log (a link to the socket below, build/entrypoint.sh):
+; what OpenDKIM - which logs through syslog(3) and nothing else - sends there
+; comes out on stdout, into the container's log (internal/syslogrelay; audit
+; 2026-10-12, L30). Before OpenDKIM, so its first lines are not lost; a
+; message sent while nothing listens is dropped by syslog(3), not queued.
+[program:syslog-relay]
+command=/usr/local/bin/panel -syslog-relay=/run/syslog/log
+user=panel
+priority=50
+autostart=true
+autorestart=true
+startretries=3
+stdout_logfile=/dev/stdout
+stdout_logfile_maxbytes=0
+stderr_logfile=/dev/stderr
+stderr_logfile_maxbytes=0
+
 [program:opendkim]
 command=/usr/sbin/opendkim -f -x /etc/opendkim.conf
 priority=100