#!/bin/sh
#
# $Id: apache.in,v 1.3.4.3 2004/09/09 22:21:54 alan Exp $
#
#	High-Availability Apache/IBMhttp control script
# 
# apache (aka IBMhttpd)
#
# Description:	starts/stops apache web servers.
#
# Author:	Alan Robertson
#
# Support:	linux-ha-dev@lists.tummy.com
#
# License:	GNU Lesser General Public License (LGPL)
#
# Copyright:	(C) 2002 International Business Machines
#
#
# An example usage in /etc/ha.d/haresources: 
#       node1  10.0.0.170 apache::/opt/IBMHTTPServer/conf/httpd.conf
#       node1  10.0.0.170 IBMhttpd
#
# Our parsing of the Apache config files is very rudimentary.
# It'll work with lots of different configurations - but not every
# possible configuration.
#
# Patches are being accepted ;-)
#
unset LC_ALL; export LC_ALL
unset LANGUAGE; export LANGUAGE

prefix=/usr
exec_prefix=/usr
. /etc/ha.d/shellfuncs

#######################################################################
#
#	Configuration options - usually you don't need to change these
#
#######################################################################
#
IBMHTTPD=/opt/IBMHTTPServer/bin/httpd
HTTPDLIST="/sbin/httpd /usr/sbin/httpd"
WGETNAME=wget
WGETOPTS="-O- -nv"
LOCALHOST="http://localhost"
HTTPDOPTS="-DSTATUS"
DEFAULT_IBMCONFIG=/opt/IBMHTTPServer/conf/httpd.conf
DEFAULT_NORMCONFIG="/etc/httpd/httpd.conf"
#
# You can also set
#	HTTPD
#	PORT
#	STATUSURL
#	PIDFILE
#	CONFIGFILE
# in this section if what we're doing doesn't work for you...
#
#	End of Configuration options
#######################################################################

CMD=`basename $0`
usage() {
  mstr=`methods | tr '\012' '|' | sed 's%|$%%' `
  cat <<-!
	usage: $0 [config-file-pathname] ($mstr)

	The config-file-pathname is the pathname to the configuration
	file for this web server.  Various appropriate defaults are
	assumed if no config file is specified.  If this command is
	invoked as *IBM*, then the default config file name is
	$DEFAULT_IBMCONFIG, otherwise the default config file
	will be $DEFAULT_NORMCONFIG.

	start	start the web server

	stop	stop the web server

	status	return the status of the web server

	methods	return the set of commands we support

	monitor	return TRUE if the web server appears to be working
		For this to be supported, you must configure mod_status
		and give it a server-status URL.  You have to have
		installed $WGETNAME for this to work.  We won't return
		monitor in the methods call if we don't know think
		that the monitor call will actually work ;-)

	$Id: apache.in,v 1.3.4.3 2004/09/09 22:21:54 alan Exp $
	!
  exit 1
}

methods_apache() {
  cat <<-!
	start
	stop
	status
	methods
	!
  case $HasStatus in
    yes)	echo "monitor";;
  esac
}
if
  [ "X$HTTPD" = X -o ! -f "$HTTPD" -o ! -x "$HTTPD" ]
then
  case $0 in
    *IBM*)	HTTPD=$IBMHTTPD
		DefaultConfig=$DEFAULT_IBMCONFIG;;
    *)	for h in $HTTPDLIST
	do
	  if
	    [ -f $h -a -x $h ]
	  then
	    HTTPD=$h
	    break
	  fi
	done
	DefaultConfig=$DEFAULT_NORMCONFIG;;
  esac
fi
#
#	Run:  Run a script, and log its output.
#
run() {
  output=`"$@" 2>&1`
  rc=$?
  if
    output=`echo $output`
  then 
    if
      [ ! -z "$output" ]
    then
      ha_log "info: $output"
    fi
    return 0
  else
    if
      [ ! -z "$output" ]
    then
      ha_log "ERROR: $output"
    else
      ha_log "ERROR: command failed: $*"
    fi
    return 1
  fi
}
#
# Strip comments, and initial blanks. Compress other blanks
#
apachecat() {
    sed -e 's%#.*%%' -e 's%^[ 	]*%%' -e 's%[ 	]+% %g' $1
}

#
# Return the value of a parameter in our apache config file
#
apache_param() {
  configfile=$1
  varname=$2

  if
    apachecat $1 | grep -i "^$varname " | \
        sed -e 's%^[^ ]* %%' -e 's%^"%%' -e 's%"$%%'
  then
     : OK
  else
     false
  fi
}

#
# Return TRUE if the config file supports the given handler somewhere
#
SupportsHandler() {
  apache_param $1 SetHandler | grep "^$2 *" >/dev/null
}

#
#	return true if the given module is loaded...
#
Module_loaded() {
  apache_param $1 AddModule | grep -i "^mod_$2\." >/dev/null
}

#
#	Return the location(s) that are handled by the given handler
#
FindLocationForHandler() {
  PerlScript='while (<>) {
	/<Location "?([^ >"]+)/i && ($loc=$1);
	'"/SetHandler +$2"'/i && print "$loc\n"; 
  }'
  apachecat $1 | perl -e "$PerlScript"
}


#
#	Get all the parameters we need from the Apache config file
#
GetParams() {
  ConfigFile=$1
  ServerRoot=`apache_param $ConfigFile ServerRoot`
  PidFile=`apache_param $ConfigFile PidFile`
  case $PidFile in
    /*)	;;
    *)	PidFile=$ServerRoot/$PidFile;;
  esac
  case "$PORT" in
    [0-9]*)	;;
    *)	PORT=`apache_param $ConfigFile Port`
        case "$PORT" in
          [0-9]*)	;;
	  *)		PORT=80;;
        esac;;
  esac
  if
    WGET=`which $WGETNAME 2>/dev/null`
  then
    : OK
  else
    WGET=""
  fi
  
  #
  # Just because they have mod_status loaded and have a server-status
  # declared doesn't mean they support the status operation.
  #
  # It's actually pretty hard to tell because of run-time defines which
  # could be turned on elsewhere...
  #
  # (we start our server with -DSTATUS - just in case :-))
  #
  # Typically (but not necessarily) the status URL is /server-status
  #
  # For us to think status will work, we have to have the following things:
  #
  # - $WGET has to exist and be executable
  # - The mod_status module must be loaded
  # - The server-status handler has to be mapped to some URL somewhere
  #
  # We assume that:
  #
  # - the "main" web server at $PORT will also support it if we can find it
  #	somewhere in the file
  # - it will be supported at the same URL as the one we find in the file
  #
  # If this doesn't work for you, then set STATUSURL at the top of the file
  #
  HasStatus=no
  if
    [ ! -z "$WGET" -a -x "$WGET" ]	\
    &&	Module_loaded $ConfigFile status	\
    &&	SupportsHandler $ConfigFile server-status
  then
    StatusURL=`FindLocationForHandler $1 server-status | tail -1`
    case "$StatusURL" in
      /*)	HasStatus=yes;;
    esac
    if
       [ "X$STATUSURL" = "X" ]
    then
      STATUSURL="${LOCALHOST}:${PORT}$StatusURL"
    fi
  fi
  if
    [ -z "$PidFile"  -o ! -f $ConfigFile ]
  then
    false
  else
    true
  fi

}

#
# return TRUE if a process with given PID is running
#
ProcessRunning() {
    ApachePID=$1
    # Use /proc if it looks like it's here...
    if
      [ -d /proc -a -d /proc/1 ]
    then
       [ -d /proc/$ApachePID ]
    else
      #  This assumes we're running as root...
      kill -0 "$ApachePID" >/dev/null 2>&1
    fi
}


silent_status() {
  if
    [ -f $PidFile  ] 
  then
    ProcessRunning `cat $PidFile`
  else
    : No pid file
    false
  fi
}

start_apache() {
  if
    silent_status
  then
    echo "$CMD already running (pid $ApachePID)"
    return 0
  fi
  run $HTTPD $HTTPDOPTS -f $CONFIGFILE
}

stop_apache() {
  if
    silent_status
  then
    if
      kill $ApachePID
    then
      tries=0
      while
        ProcessRunning $ApachePID &&
        [ $tries -lt 10 ]
      do
        sleep 1
        kill $ApachePID >/dev/null 2>&1
        ha_log "Killing apache PID $ApachePID"
        tries=`expr $tries + 1`
      done
    else
      ha_log "Killing apache PID $ApachePID FAILED."
    fi
    if
      ProcessRunning $ApachePID
    then
      echo "$CMD still running ($ApachePID)."
      ha_log "$CMD still running ($ApachePID)."
      false
    else
      echo "$CMD stopped."
    fi
  else
    echo "$CMD not running."
    ha_log "$CMD is not running."
  fi
}

status_apache() {
  silent_status
  rc=$?
  if
    [ $rc -eq 0 ]
  then
    echo "$CMD is running (pid $ApachePID)."
  else
    echo "$CMD is stopped."
  fi
  return $rc
}


monitor_apache() {
  case $HasStatus in
    no)	echo "Monitoring not supported by $CONFIGFILE"
	return 1;;
  esac
  if
    silent_status
  then
    run sh -c "$WGET $WGETOPTS $STATUSURL | grep -i '</ *body *></ *html *>' >/dev/null"
  else
    echo "$CMD not running"
    return 1
  fi
}

if
  [ $# -gt 1 ]
then
  CONFIGFILE=$1
  COMMAND=$2
else
  case "$CONFIGFILE" in
    "") CONFIGFILE=$DefaultConfig;;
    *)		;;
  esac
  COMMAND=$1
fi

if
  [ ! -f "$CONFIGFILE" -a "X$COMMAND" = Xstop ]
then
  echo "$CONFIGFILE not found - apache considered stopped"
  exit 0
fi

if
  GetParams $CONFIGFILE
then
  : OK
else
  echo "Cannot parse config file [$CONFIGFILE]"
  exit 1
fi

case $COMMAND in
  start)	start_apache;;
  stop)		stop_apache;;
  status)	status_apache;;
  methods)	methods_apache;;
  monitor)	monitor_apache;;
  *)		usage;;
esac