Bug#926390: sysvinit-utils: /lib/init/init-d-script always fails when VERBOSE=no

[Dmitry Bogatov]

control: severity -1 important

[2019-04-04 12:44] Marc Lehmann <debian-reportbug at plan9.de>
> Package: sysvinit-utils
> Version: 2.88dsf-59.9
> Severity: normal
>
> Dear Maintainer,
>
> I tried to install the snmpd package, but the post-install script always
> failed because invoke-rc.d snm,pd restart failed.
>
> Surprisingly, running it interactively always worked.
>
> It turned out the problem was /lib/init/init-d-script's jandling of
> VERBOSE, in shoprt, if VERBOSE=no, it always fails.
>
> The reason is that "snmpd restart" falls through to the last case
> statement in init-s-script:
>
>      restart)
>            call do_restart
>            ;;
>    ...
>    exit $? # See https://bugs.debian.org/822753#53
>
> do_restart looks like this:
>
>         call do_start_cmd
>         case "$?" in
>                 0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
>                 2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
>         esac
>
> and this always has exit status 1, as do_startr_cmd returns either 0, 1
> or 2, and in all cases, [ no != no ] is false, so the exit status becomes
> false, and thuis the whole init script exit status becomes false.
>
> The end result is that the snmpd package always failed postinstall and
> couldn't be removed either, while it's init-scripot works fine when
> running at the shell, because VERBOSE isn't "no".
>
> If this is a bug in snmpd's init script, could you reassign
> it to the correct package?

Thank you for so in-depth research. I believe this issue is resolved as
side-effect of #427889 in commit 26e498959, included in release 2.94-2.
Can you please try upgrading initscripts to 2.94-2 or applying patch,
included in this mail and see, whether it solves problem?

Non-uninstallable package is bad, very bad. I am afraid, we will need
upload to unstable and unblock from release team.

From 26e4989597d0fca9348443721c512f2b6774971c Mon Sep 17 00:00:00 2001
From: Dmitry Bogatov <KAction at debian.org>
Date: Sun, 24 Mar 2019 22:18:22 +0000
Subject: [PATCH] Make init-d-scripts exit with sensible values (Closes:
 #427889)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

According to Policy=4.3.0.3,

	The "init.d" scripts must ensure that they will behave sensibly (i.e.,
	returning success and not starting multiple copies of a service) if
	invoked with "start" when the service is already running, or with
	"stop" when it isn’t, and that they don’t kill unfortunately-named
	user processes.

This patch ensures, that exit values, returned by start-stop-daemon(8)
are sensible and propagated correctly into do_{start,stop,restart} functions.

Unfortunately, as resolved in #426877, --oknodo option is opt-in, and
default behaviour of start-stop-daemon is non-sensible with regard of
starting/stopping daemon, already running/stopped.
---
 debian/init-d-script | 38 +++++++++++++++-----------------------
 1 file changed, 15 insertions(+), 23 deletions(-)

diff --git a/debian/init-d-script b/debian/init-d-script
index 131dbd65..59ae3221 100755
--- a/debian/init-d-script
+++ b/debian/init-d-script
@@ -43,22 +43,10 @@ call() {
 # Function that starts the daemon/service
 #
 
-# Return
-#   0 if daemon has been started
-#   1 if daemon was already running
-#   2 if daemon could not be started
 do_start_cmd() {
-	start-stop-daemon --start --quiet ${PIDFILE:+--pidfile ${PIDFILE}} \
-	    $START_ARGS \
-	    --startas $DAEMON --name $NAME --exec $DAEMON --test > /dev/null \
-	    || return 1
-	start-stop-daemon --start --quiet ${PIDFILE:+--pidfile ${PIDFILE}} \
-	    $START_ARGS \
-	    --startas $DAEMON --name $NAME --exec $DAEMON -- $DAEMON_ARGS \
-	    || return 2
-	# Add code here, if necessary, that waits for the process to be ready
-	# to handle requests from services started subsequently which depend
-	# on this one.  As a last resort, sleep for some time.
+	start-stop-daemon --start --quiet --oknodo \
+	    ${PIDFILE:+--pidfile ${PIDFILE}} $START_ARGS \
+	    --startas $DAEMON --name $NAME --exec $DAEMON -- $DAEMON_ARGS
 }
 
 do_start()
@@ -68,12 +56,15 @@ do_start()
 	fi
 	[ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
 	call do_start_cmd
-	case "$?" in
+	retval=$?
+	case ${retval} in
 		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
 		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
 	esac
 	if is_call_implemented do_start_cleanup ; then
 		call do_start_cleanup
+	else
+		return ${retval}
 	fi
 }
 
@@ -81,11 +72,6 @@ do_start()
 # Function that stops the daemon/service
 #
 
-# Return
-#   0 if daemon has been stopped
-#   1 if daemon was already stopped
-#   2 if daemon could not be stopped
-#   other if a failure occurred
 do_stop_cmd() {
 	start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 \
 	    $STOP_ARGS \
@@ -114,12 +100,15 @@ do_stop()
 	fi
 	[ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
 	call do_stop_cmd
-	case "$?" in
+	retval=$?
+	case ${retval} in
 		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
 		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
 	esac
 	if is_call_implemented do_stop_cleanup ; then
 		call do_stop_cleanup
+	else
+		return ${retval}
 	fi
 }
 
@@ -130,12 +119,15 @@ do_restart() {
 	[ "$VERBOSE" != no ] && log_daemon_msg "Restarting $DESC" "$NAME"
 	call do_stop_cmd
 	call do_start_cmd
-	case "$?" in
+	retval=$?
+	case ${retval} in
 		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
 		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
 	esac
 	if is_call_implemented do_restart_cleanup ; then
 		call do_restart_cleanup
+	else
+		return ${retval}
 	fi
 }
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