#!/bin/sh
#
-# shutdown -- wrapper script to prevent erroneous shutdowns via SSH
+# shutdown -- wrapper script to guard against accidental shutdowns
#
# Copyright © martin f. krafft <madduck@madduck.net>
# Released under the terms of the Artistic Licence 2.0
set -eu
ME=molly-guard
+VERSION=0.4
+SCRIPTSDIR=/etc/molly-guard/run.d
+SCRIPTSDIR="${0%/*}/run.d"
CMD="${0##*/}"
EXEC="/sbin/$CMD"
usage()
{
cat <<-_eousage
- Usage: $ME [options]
+ Usage: $ME [options] [-- script options]
(shielding $EXEC)
+
+ molly-guard's primary goal is to guard against accidental
+ shutdowns/reboots. $ME will run all scripts in $SCRIPTSDIR and only
+ invokes $EXEC if all scripts exited successfully.
- Instead of invoking $EXEC directly, $ME will run a number of checks
- to guard against accidental shutdowns/reboots.
-
- Some of the checks available are:
- - Prompt the user for the machine's if the current shell is a child
- of an SSH connection (or --pretend-ssh) has been given on the
- command line, if the shell is connected to an interactive
- terminal, and the actual command to execute is does not involve
- --help or is \`shutdown -c'.
-
- $ME will always interpose the prompt if the environment variable
- ALWAYS_MOLLY is set to '1'. This variable may be set in the file
- /etc/default/${ME} .
-
- - Print out a warning message with information about this host
- before the action takes place. You can use:
- /etc/molly-guard.<Action>.message
- To print out a message specific to the command you're trying to
- use. Or:
- /etc/molly-guard.message
- For a general warning message.
-
- Only if the user satisfies all the checks will $ME take action.
Specifying --molly-guard-do-nothing as argument to the command will
- make $ME echo the command it would execute rather than actually executing
- it.
+ make $ME echo the command it would execute rather than actually
+ executing it.
+
+ Options following the double hyphen will be passed unchanged to the
+ scripts.
+
+ Please see molly-guard(8) for more information.
The actual command's help output follows:
_eousage
}
-ARGS=
+CMDARGS=
+SCRIPTARGS=
+END_OF_ARGS=0
DO_NOTHING=0
-CHECK_ARGS=
for arg in "$@"; do
case "$arg" in
(*-molly-guard-do-nothing) DO_NOTHING=1;;
eval $EXEC --help 2>&1
exit 0
;;
- (*-pretend-ssh) CHECK_ARGS="${CHECK_ARGS:+$CHECK_ARGS }--arg --pretend-ssh";;
- *) ARGS="${ARGS:+$ARGS }$arg";;
+ --) END_OF_ARGS=1;;
+ *)
+ if [ $END_OF_ARGS -eq 0 ]; then
+ CMDARGS="${args:+$args }$arg"
+ else
+ SCRIPTARGS="${args:+$args }--arg $arg"
+ fi
+ ;;
esac
done
do_real_cmd()
{
if [ $DO_NOTHING -eq 1 ]; then
- echo "$ME: would run: $EXEC $ARGS"
+ echo "$ME: would run: $EXEC $CMDARGS"
exit 0
else
- eval exec $EXEC "$ARGS"
+ eval exec $EXEC "$CMDARGS"
fi
}
if [ $DO_NOTHING -eq 1 ]; then
- echo "I: demo mode; $ME will not do anything due to --molly-guard-do-nothing."
+ echo "I: demo mode; $ME will not do anything due to --molly-guard-do-nothing." >&2
fi
# pass through certain commands
-case "$CMD $ARGS" in
- (*shutdown\ *-c*)
- echo "I: executing $CMD $ARGS regardless of check results."
+case "$CMD $CMDARGS" in
+ (*shutdown\ *-c*)
+ # allow canceling shutdowns
+ echo "I: executing $CMD $CMDARGS regardless of check results." >&2
do_real_cmd
;;
esac
-run-parts --exit-on-error --arg $CMD $CHECK_ARGS /usr/share/molly-guard/checks.d
+MOLLYGUARD_CMD=$CMD; export MOLLYGUARD_CMD
+MOLLYGUARD_DO_NOTHING=$DO_NOTHING; export MOLLYGUARD_DO_NOTHING
+MOLLYGUARD_SETTINGS="/etc/molly-guard/rc"; export MOLLYGUARD_SETTINGS
-# run-parts won't return to us if there are failures, but I'm paranoid.
-if [ $? == 0 ]; then
- do_real_cmd
- exit
-fi
+for script in $(run-parts --test $SCRIPTSDIR); do
+ ret=0
+ eval $script $SCRIPTARGS || ret=$?
+ if [ $ret -ne 0 ]; then
+ echo "W: aborting $CMD due to ${script##*/} exiting with code $ret." >&2
+ exit $ret
+ fi
+done
+
+do_real_cmd