]> git.madduck.net Git - code/molly-guard.git/blobdiff - shutdown

madduck's git repository

Every one of the projects in this repository is available at the canonical URL git://git.madduck.net/madduck/pub/<projectpath> — see each project's metadata for the exact URL.

All patches and comments are welcome. Please squash your changes to logical commits before using git-format-patch and git-send-email to patches@git.madduck.net. If you'd read over the Git project's submission guidelines and adhered to them, I'd be especially grateful.

SSH access, as well as push access can be individually arranged.

If you use my repositories frequently, consider adding the following snippet to ~/.gitconfig and using the third clone URL listed for each project:

[url "git://git.madduck.net/madduck/"]
  insteadOf = madduck:

Add a check which possibly prints out a warning message.
[code/molly-guard.git] / shutdown
index 0135f1aa435ba2fb38e77529b767983e44b0ad21..c8005adc3c5b1984dfa8d2878d5d285246abcba7 100755 (executable)
--- a/shutdown
+++ b/shutdown
@@ -30,52 +30,87 @@ case "$CMD" in
     exit 1
     ;;
 esac
-ARGS="$@"
 
-do_real_cmd()
+usage()
 {
-  case "$ARGS" in
-    (*--molly-guard-do-nothing*)
-      ARGS0="${ARGS%%--molly-guard-do-nothing*}"
-      ARGS1="${ARGS##*--molly-guard-do-nothing}"
-      echo "$ME: would run: $EXEC ${ARGS0# } ${ARGS1# }"
-      exit 0;;
-    *) eval exec $EXEC "$ARGS";;
-  esac
-}
+  cat <<-_eousage
+       Usage: $ME [options]
+              (shielding $EXEC)
 
-# require an interactive terminal connected to stdin
-test -t 0                    || do_real_cmd
+       Instead of invoking $EXEC directly, $ME will run a number of checks
+        to guard against accidental shutdowns/reboots.
 
-# only run if we are being called over SSH, that is if the current terminal
-# was created by sshd.
-PTS=$(readlink /proc/$$/fd/0)
-pgrep -f "^sshd.+${PTS#/dev/}[[:space:]]*$" >/dev/null || do_real_cmd
+        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'.
 
-# pass through help commands
-case "$CMD $ARGS" in
-  (shutdown\ *-c*) do_real_cmd;;
-  (shutdown\ *-h*) do_real_cmd;;
-  (*--help*) do_real_cmd;;
-  *) :;;
-esac
+         $ME will always interpose the prompt if the environment variable
+          ALWAYS_MOLLY is set to '1'.  This variable may be set in the file
+         /etc/default/${ME} .
 
-HOSTNAME="$(hostname)"
+        - 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.
 
-sigh()
-{
-  echo "Good thing I asked; I won't $CMD $HOSTNAME ..."
-  exit 2
+       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.
+
+       The actual command's help output follows:
+
+       _eousage
 }
 
-trap 'echo;sigh' 1 2 3 9 10 12 15
+ARGS=
+DO_NOTHING=0
+CHECK_ARGS=
+for arg in "$@"; do
+  case "$arg" in
+    (*-molly-guard-do-nothing) DO_NOTHING=1;;
+    (*-help)
+      usage 2>&1
+      eval $EXEC --help 2>&1
+      exit 0
+      ;;
+    (*-pretend-ssh) CHECK_ARGS="${CHECK_ARGS:+$CHECK_ARGS }--arg --pretend-ssh";;
+    *) ARGS="${ARGS:+$ARGS }$arg";;
+  esac
+done
+
+do_real_cmd()
+{
+  if [ $DO_NOTHING -eq 1 ]; then
+    echo "$ME: would run: $EXEC $ARGS"
+    exit 0
+  else
+    eval exec $EXEC "$ARGS"
+  fi
+}
 
-echo "$ME: SSH session detected!"
-echo -n "Please type in hostname of the machine to $CMD: "
-read HOSTNAME_USER || :
+if [ $DO_NOTHING -eq 1 ]; then
+  echo "I: demo mode; $ME will not do anything due to --molly-guard-do-nothing."
+fi
 
-[ "$HOSTNAME_USER" = "$HOSTNAME" ] || sigh
+# pass through certain commands
+case "$CMD $ARGS" in
+  (*shutdown\ *-c*) 
+    echo "I: executing $CMD $ARGS regardless of check results."
+    do_real_cmd
+    ;;
+esac
 
-trap - 1 2 3 9 10 12 15
+run-parts --exit-on-error $CHECK_ARGS /usr/share/molly-guard/checks.d
 
-do_real_cmd
+# run-parts won't return to us if there are failures, but I'm paranoid.
+if [ $? == 0 ]; then
+  do_real_cmd
+  exit
+fi