From: Michael Tokarev <mjt@tls.msk.ru>
Date: Tue, 24 Dec 2024 12:21:10 +0300
Subject: add "debian-systemd-start" subcommand to postfix-script
Forwarded: not-needed

In order to have stricter privileges at runtime, there's a need
to split postfix startup procedure to "setup" stage and "runtime"
stage, because "setup" stage requires more privileges (for example,
it does `create-missing`, which needs chown).  In Debian, for
systemd startup, we run `postfix check` in ExecStartPre with full
privs, and `postfix debian-systemd-start` in regular ExecStart,
with restricted privileges.

diff --git a/conf/postfix-script b/conf/postfix-script
--- a/conf/postfix-script
+++ b/conf/postfix-script
@@ -127,4 +127,15 @@ stop_msg)
 	;;
 
+debian-systemd-start) # debian-specific
+	# Second part of the startup.  First part is done in ExecStartPre.
+	rm -f $queue_directory/quick-start
+	rm -f $queue_directory/debian-systemd-start #XXX read MAIL_DEBUG & MAIL_VERBOSE
+	[ -d /run/systemd/system ] && [ -n "$INVOCATION_ID" ] || {
+		$FATAL "the Postfix mail system is started through systemd but not under systemd?"
+		exit 1
+	}
+	$daemon_directory/master -w
+	;;
+
 start|start-fg)