supervision as supervisord does it: Postfix stopped, give-ups FATAL, reload's exit read

C-P42. postfix-script's start-fg runs master as its child and master
calls setsid() (Postfix 3.7.11, conf/postfix-script; src/master/master.c);
supervisord signals the pid alone (supervisor 4.2.5, process.py,
Subprocess.kill()). A stop of program postfix left master running - a
restart then found "already running" - and a container stop cut Postfix
off with SIGKILL. The wrapper now stays the parent of "postfix start-fg"
and on TERM/INT runs "postfix stop", asking again while start-fg is still
in its checks (master -t). stopwaitsecs=15.

C-V6. The wrapper's give-up on the milter sockets came after the default
startsecs, so it was EXITED and restarted for ever. startsecs is now
MILTER_WAIT_TIMEOUT + 10, exported by the entrypoint as POSTFIX_STARTSECS
and expanded by supervisord (options.py, processes_from_section(); a
non-number MILTER_WAIT_TIMEOUT stops the start): a give-up is "Exited too
quickly", BACKOFF, FATAL after startretries, crashexit. For those seconds
after each start the program is STARTING (the healthcheck's 90 s start
period covers it; the sender check counts no downtime then).

C-V5. logrotate had startsecs=0, so a refused config restarted it every
second for ever. startsecs=1: FATAL after startretries; crashexit reads
the event's processname and leaves logrotate's FATAL on Server > Health.

B-U2. "supervisorctl start" returns when a startsecs=0 program is RUNNING,
not when it ends, and mapped "already started" to success. The panel now
speaks supervisord's XML-RPC itself (internal/supervisor, RunOnce):
startProcess without waiting, getProcessInfo until it leaves
STARTING/RUNNING, exitstatus 0 or an error; a run in progress is waited
out and one of its own follows. A failed reload while program postfix is
not RUNNING is logged, not an error: the next master reads the files.
C-V10: postfix-reload rests EXITED after a run; the e2e process check
takes STOPPED or EXITED. C-P34: the dead "postfix set-permissions" branch
goes - postfix check's create-missing builds the queue tree.

Stand (2026-10-14, make e2e, exit 0; MILTER_WAIT_TIMEOUT=10 on the stand):
new supervision_stops_postfix_and_gives_up - supervisorctl restart postfix
writes postfix-script's "stopping the Postfix mail system" and leaves one
master; with the panel's sockets removed, start answers "postfix: ERROR
(spawn error)" (finish() sets spawnerr "Exited too quickly", onwait()
reads it first) and Postfix comes up once the panel is back; a
group-writable logrotate config ends FATAL with the container up; the
panel's Reload configuration answers only after mail.log has "refreshing
the Postfix mail system", postfix-reload EXITED. session_survives_restart
sees the stop line for the container's restart. Measured: master's own
"terminating on signal 15" never reaches mail.log (master TERMs its group,
postlogd included, before it logs). go vet and go test ./... pass on the
server (24 packages; new unit tests of RunOnce against a fake supervisord).

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

internal/postfix/postfix.go

@@ -7,6 +7,7 @@ package postfix
 
 import (
 	"fmt"
+	"log"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -186,6 +187,25 @@ func assertMapSafe(address, login string) error {
 // whenever it is convenient" while new ones get the new configuration; a
 // texthash table is read into memory once per process
 // (README_FILES/DATABASE_README).
+//
+// The call returns when "postfix reload" has ended, with an error unless it
+// exited 0 (a postsuper failure, a main.cf postfix(1) cannot read:
+// conf/postfix-script, "reload"; src/postfix/postfix.c), which the page that
+// saved shows. Before, supervisorctl's start returned as the reload was
+// spawned, and a reload already running counted as done though it may have
+// read the files before this change (supervisor.RunOnce; assumptions B-U2).
+// A reload that fails while program postfix is not RUNNING - stopped, or
+// still in its start, the wrapper waiting for the milter sockets - is no
+// error: "the Postfix mail system is not running", and the master that starts
+// next reads the files as they are now.
 func reloadViaSupervisor() error {
-	return supervisor.Start("postfix-reload")
+	err := supervisor.RunOnce("postfix-reload")
+	if err == nil {
+		return nil
+	}
+	if state, serr := supervisor.State("postfix"); serr == nil && state != "RUNNING" {
+		log.Printf("postfix: reload while program postfix is %s, left to its start: %v", state, err)
+		return nil
+	}
+	return err
 }