#!/bin/bash
# squid		This shell script takes care of starting and stopping
#		Squid Internet Object Cache
#
####################################################################################
#     Downloaded from http://www.techyouruniverse.com/squid-init-script/           #
####################################################################################
#
# Version 0.1 01/03/2008
# I took the existing CentOS init script (unknown origin) and improved the following:
# ) Added clearcache method for clearing cache
# ) Added configtest method for checking syntax of config file
# ) Optimized restart/stop for minimum downtime
# ) Cleaned up config variables
# ) Cleaned up formatting of output 
#
####################################################################################
#    Please send improvements/comments to nick at sullivanflock.com                #
####################################################################################
#
#
# chkconfig: - 90 25
# description: Squid - Internet Object Cache. Internet object caching is \
# 	a way to store requested Internet objects (i.e., data available \
# 	via the HTTP, FTP, and gopher protocols) on a system closer to the \
#	requesting site than to the source. Web browsers can then use the \
#	local Squid cache as a proxy HTTP server, reducing access time as \
#	well as bandwidth consumption.
# pidfile: /var/run/squid.pid
# config: /etc/squid/squid.conf

PATH=/usr/bin:/sbin:/bin:/usr/sbin
export PATH

# Source function library.
. /etc/rc.d/init.d/functions

# Source networking configuration.
. /etc/sysconfig/network

# Check that networking is up.
[ ${NETWORKING} = "no" ] && exit 0

# locations of files
SQUID_OUT_FILE=/var/log/squid/squid.out
SQUID_CONF_FILE=/etc/squid/squid.conf

# check if the squid conf file is present
[ -f $SQUID_CONF_FILE ] || exit 0

if [ -f /etc/sysconfig/squid ]; then
  . /etc/sysconfig/squid
fi

# don't raise an error if the config file is incomplete 
# set defaults instead:
SQUID_OPTS=${SQUID_OPTS:-"-D"}
SQUID_PIDFILE_TIMEOUT=${SQUID_PIDFILE_TIMEOUT:-20}
SQUID_SHUTDOWN_TIMEOUT=${SQUID_SHUTDOWN_TIMEOUT:-100}


# determine the name of the squid binary
[ -f /usr/sbin/squid ] && SQUID=squid
[ -z "$SQUID" ] && exit 0

prog="$SQUID"

# determine which one is the cache_swap directory
CACHE_SWAP=`sed -e 's/#.*//g' $SQUID_CONF_FILE | \
	grep cache_dir |  awk '{ print $3 }'`
[ -z "$CACHE_SWAP" ] && CACHE_SWAP=/var/spool/squid

RETVAL=0

start() {
    for adir in $CACHE_SWAP; do
        if [ ! -d $adir/00 ]; then 
	     echo -n "init_cache_dir $adir... "
	     $SQUID -z -F -D >> $SQUID_OUT_FILE 2>&1
	fi
    done
    echo -n $"Starting $prog: "
    $SQUID $SQUID_OPTS >> $SQUID_OUT_FILE 2>&1
    RETVAL=$?
    if [ $RETVAL -eq 0 ]; then 
       timeout=0;
       while : ; do
          [ ! -f /var/run/squid.pid ] || break
	  if [ $timeout -ge $SQUID_PIDFILE_TIMEOUT ]; then
	     RETVAL=1
	     break
	  fi
	  sleep 1 && echo -n "."
	  timeout=$((timeout+1))
       done
    fi
    [ $RETVAL -eq 0 ] && touch /var/lock/subsys/$SQUID
    [ $RETVAL -eq 0 ] && echo_success
    [ $RETVAL -ne 0 ] && echo_failure
    echo
    return $RETVAL
}

stop() {
    echo -n  $"Stopping $prog: "
    $SQUID -k check >> $SQUID_OUT_FILE 2>&1
    RETVAL=$?
    if [ $RETVAL -eq 0 ] ; then
        # "-k interrupt" sends an INT signal, which causes Squid to shutdown immediately,
        # without waiting for current connections to die. You can use "-k shutdown" to
        # be more gentle to existing connections, but this causes squid to take
        # 10+ seconds to shut down. I prefer a quicker shutdown.
        # $SQUID -k shutdown &
        $SQUID -k interrupt &
    	rm -f /var/lock/subsys/$SQUID
	timeout=0
 	while : ; do
		[ -f /var/run/squid.pid ] || break
		if [ $timeout -ge $SQUID_SHUTDOWN_TIMEOUT ]; then
		    echo
		    return 1
		fi
		sleep 1 && echo -n "." 
		timeout=$((timeout+1))
    	done
	echo_success
	echo 
    else
        $SQUID -k check 
        echo_failure
	echo
    fi
    return $RETVAL
}    

reload() {
    $SQUID $SQUID_OPTS -k reconfigure 
    [ $? -eq 0 ] && echo_success
    [ $RETVAL -ne 0 ] && echo_failure
    echo 
}

restart() {
    stop
    start
}    

condrestart() {
    [ -e /var/lock/subsys/squid ] && restart || :
}

rhstatus() { 
    status $SQUID
    $SQUID -k check
}

configtest() { 
    echo -n "Checking syntax of $SQUID_CONF_FILE:"
    $SQUID $SQUID_OPTS -k parse
    [ $? -eq 0 ] && echo_success
    [ $RETVAL -ne 0 ] && echo_failure
    echo
}

# Wipe all the squid cache. Note that not all squid cache is stored in memory,
# some is stored on disk. So a simple restart of squid is insufficient.
# This process is optimized for high availability at the cost of some elegance.
# This used to simply "rm" the directory, but this was very slow (60+ seconds)
# for a large cache, so I changed to a "mv" instead.
# Steps are:
# 1. Stop squid.
# 2. Rename squid cache dir
# 3. Recreate squid cache dir
# 4. Start squid
# 5. Remove old cache dir

clearcache() { 
    stop

    echo -n  $"Renaming $CACHE_SWAP to: $CACHE_SWAP.bad"
    mv $CACHE_SWAP/ $CACHE_SWAP.bad
    [ $? -eq 0 ] && echo_success
    [ $RETVAL -ne 0 ] && echo_failure 
    echo 


    echo -n  $"Recreating $prog cache directories: "
    # Recreating empty directory with same owner/permissions
    chown=`stat -c%U:%G $CACHE_SWAP.bad`
    mkdir $CACHE_SWAP
    chown $chown $CACHE_SWAP
    # Fill the directory with squids cache sub directories
    $SQUID -z >> $SQUID_OUT_FILE 2>&1
    [ $? -eq 0 ] && echo_success
    [ $RETVAL -ne 0 ] && echo_failure
    echo

    start 

    echo -n  $"Squid is up, removing $CACHE_SWAP.bad"
    rm -rf $CACHE_SWAP.bad
    [ $? -eq 0 ] && echo_success
    [ $RETVAL -ne 0 ] && echo_failure
    echo 
}


case "$1" in
start)
    start
    ;;

stop)
    stop
    ;;

reload)
    reload
    ;;

restart)
    restart
    ;;

condrestart)
    condrestart
    ;;

status)
    rhstatus
    ;;

configtest)
    configtest
    ;;

clearcache)
    clearcache
    ;;

*)
    echo $"Usage: $0 {start|stop|status|reload|restart|condrestart|configtest|clearcache}"
    exit 1
esac

exit $?