#!/bin/sh
## ----------------------------------------------------------------------
## check_server_daemons.sh -- a script to see if various demon are UP.
##
## Here is a script that will check to see if various deamons are running.
## If they are not, a message is printed out and -- if configured -- the 
## demon is restarted.  mail has a flag to not mail anything unless the
## body of the message has text.  So, read your mail man page, and pipe
## the output of this script into the mail program.  The flag is -e in 
## Linux and -E in FreeBSD.
##
## set this up in a cronjob like this:
## @hourly /path/to/this/script/check_server_daemons.sh | mail -e -s '[ERROR] checking server' gregory@example.org
## ----------------------------------------------------------------------
#  Thu Mar 15 15:58:38 PDT 2007 (c) Rudy Rucker

## ----------------------------------------------------------------------
## Configure ports to check at the end of the script...
## ----------------------------------------------------------------------

uname='FreeBSD';
[ -x /bin/uname ] && uname=`uname`;
[ -x /usr/bin/uname ] && uname=`uname`;

# set this to 0 chen cron'd
DEBUG=1;

check_netstat () {
	IP=$1; PORT=$2 NAME=$3; START_CMD=$4
	if [ uname = 'Linux' ]; then
		[ PORT = '*' ] && PORT='0.0.0.0'
		NUM=`/bin/netstat -ln | /bin/grep -c "$IP:$PORT .*LISTEN"`
	else
		NUM=`/usr/bin/netstat -an | /usr/bin/grep -c "$IP.$PORT .*LISTEN"`
	fi

	if  [ $NUM -lt 1 ]; then
		echo "ERROR!  $0 detected $NAME was not running."
		echo "This ip: $IP and this port: $PORT were checked."
		date
		if [ -n "$START_CMD" ] ; then
			echo "Attempting to restart with: $START_CMD"
			$START_CMD &
			if [ -z "$DEBUG" ] && [ $DEBUG = 0 ]; then
				sleep 1;
				echo "Here is the current ps output"
				echo "   ============   ============   ============   ============"
				/bin/ps -ax
				echo "   ============   ============   ============   ============"
			fi
		fi
		echo
	elif [ -n "$DEBUG" ] && [ $DEBUG = 1 ]; then
		echo "$NAME OK";
	fi
}

## # Linux examples
## check_netstat "*" 21 pure-ftp "/etc/init.d/pure-ftpd-mysql start"
## check_netstat "*" 25 postfix "/etc/init.d/postfix start"
## check_netstat 69.22.154.64 80 "web server" "/etc/init.d/apache2 start"
## check_netstat 69.22.154.65 80 "other web server" "/etc/init.d/apache2 start"
## check_netstat "*" 110 pop3 "/etc/init.d/courier-pop start"
## check_netstat 127.0.0.1 3306 mysqld "/etc/init.d/mysql start"
## 
## # FreeBSD examples
## check_netstat "*" 21 pure-ftp "/usr/local/etc/rc.d/pure-ftpd start"
## check_netstat 69.22.154.64 80 "web server" "/etc/init.d/apache2 start"
check_netstat 69.22.154.65 80 "other web server" "/etc/init.d/apache2 start"
## check_netstat "*" 110 pop3 "/etc/init.d/courier-pop start"
## check_netstat * 3306 mysqld "/usr/local/etc/rc.d/mysql-server.sh start"
## check_netstat 127.0.0.1 53 "Local DNS cacher " "/etc/rc.d/named start"
 
# this is a neat test... runs nc listening on localhost.  
check_netstat 127.0.0.1 9999 "Test server on port 9999" "nc -l -p 9999 -s 127.0.0.1"


## ----------------------------------------------------------------------
## People should put this crap at the end, not the top of their software.
## ----------------------------------------------------------------------
##   Copyright (c) 2007 Rudy Rucker
##   
##   Permission is hereby granted, free of charge, to any person
##   obtaining a copy of this software and associated documentation
##   files (the "Software"), to deal in the Software without
##   restriction, including without limitation the rights to use,
##   copy, modify, merge, publish, distribute, sublicense, and/or sell
##   copies of the Software, and to permit persons to whom the
##   Software is furnished to do so, subject to the following
##   conditions:
##   
##   The above copyright notice and this permission notice shall be
##   included in all copies or substantial portions of the Software.
##   
##   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
##   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
##   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
##   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
##   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
##   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
##   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
##   OTHER DEALINGS IN THE SOFTWARE.
## ----------------------------------------------------------------------