net_watchdog.initd

#!/bin/bash
# (c) 2020 Leif Sawyer
# License: GPL 3.0 (see https://github.com/akhepcat/)
# Permanent home:  https://github.com/akhepcat/Miscellaneous/
# Direct download: https://raw.githubusercontent.com/akhepcat/Miscellaneous/master/net_watchdog.initd
# 

### BEGIN INIT INFO
# Provides:		net_watchdog
# Required-Start:	$network $syslog
# Required-Stop:	$network $syslog
# Default-Start:	2 3 4 5
# Default-Stop:		0 1 6
# Short-Description:	Reboot system if network goes unresponsive between host and default gw
### END INIT INFO

NAME=net_watchdog
DESC="network watchdog for end-to-end connectivity validation"

RUNDIR=/run/${NAME}
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DAEMON=/usr/local/sbin/${NAME}d
SCRIPTNAME="/etc/init.d/${0##*/}"
PIDFILE=$RUNDIR/$NAME.pid

# Exit if the package is not installed
[ -x "$DAEMON" ] || exit 0

# Read configuration variable file if it is present
[ -r /etc/default/$NAME ] && . /etc/default/$NAME

if [ -z "$IFACE" ]; then
	# this should be overridden locally
	IFACE=eth0
fi


# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh

# Define LSB log_* functions.
# Depend on lsb-base (>= 3.0-6) to ensure that this file is present.
. /lib/lsb/init-functions


do_start()
{
        # Return
        #   0 if daemon has been started
        #   1 if daemon was already running
        #   2 if daemon could not be started

        mkdir -p $RUNDIR || return 2

        start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON --test > /dev/null \
                || return 1
        start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON -- ${IFACE:-eth0} \
                || return 2
}

do_stop()
{
        # 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
        start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 --pidfile $PIDFILE --name $NAME
        RETVAL="$?"
        [ "$RETVAL" = 2 ] && return 2
        # Many daemons don't delete their pidfiles when they exit.
        rm -f $PIDFILE
        return "$RETVAL"
}

case "$1" in
  start)
        if [ "$START_DAEMON" = "true" ]; then
                [ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
                do_start
                case "$?" in
                        0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
                        2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
                esac
        else
                [ "$VERBOSE" != no ] && \
                        log_daemon_msg "Not starting $DESC" "$NAME" && \
                        log_end_msg 0
        fi
        ;;
  stop)
        [ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
        do_stop
        case "$?" in
                0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
                2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
        esac
        ;;
  status)
       status_of_proc "$DAEMON" "$NAME" && exit 0 || exit $?
       ;;
  reload|force-reload|restart)
        #
        # If the "reload" option is implemented then remove the
        # 'force-reload' alias
        #
        log_daemon_msg "Restarting $DESC" "$NAME"
        do_stop
        case "$?" in
          0|1)
                do_start
                case "$?" in
                        0) log_end_msg 0 ;;
                        1) log_end_msg 1 ;; # Old process is still running
                        *) log_end_msg 1 ;; # Failed to start
                esac
                ;;
          *)
                # Failed to stop
                log_end_msg 1
                ;;
        esac
        ;;
  *)
        echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2
        exit 3
        ;;
esac