#!/bin/sh
#
## Script to manage XEN virtual machines as cluster resources
#
# Created: Ivan A. Vari, Oct 2007, <i.vari@niwa.co.nz>
# Version: 1.2
# License: Free

# Executables
CRM_ADMIN=/usr/sbin/crmadmin
CRM_RESOURCE=/usr/sbin/crm_resource
CRM_STANDBY=/usr/sbin/crm_standby
ECHO_BIN=/bin/echo
AWK_BIN=/usr/bin/awk
GREP_BIN=/usr/bin/grep

# Space separated list of domUs should not be migrated 
EXCLUDE=""

##---------NO NEED CHANGING ANYTHING BELOW----------##

# Variables
DOMAINS=`$CRM_RESOURCE -L | $GREP_BIN Xen | $AWK_BIN '{ print $1 }'` 	# filtering valid domUs
HOSTS=`$CRM_ADMIN -N | $AWK_BIN '{ print $3 }'`				# filtering valid nodes

# This is a function for the displaying the error / help / usage message
usage_msg()
    {
        $ECHO_BIN
        $ECHO_BIN "A script to manage XEN virtual machines as cluster resources in HA stack."
        $ECHO_BIN "Remember: once domU is configured in heartbeat as a cluster resource, it"
        $ECHO_BIN "shouldn't be managed by traditional utilities such as \"xm\" or \"libvirt\"(GUI)"
        $ECHO_BIN
        $ECHO_BIN "Usage: ${0##*/} <subcommand> [resource] [node]"
        $ECHO_BIN
        $ECHO_BIN "subcommands:"
        $ECHO_BIN -e "\033[1m list\033[0m                         Displays available Xen cluster resources (domU)"
	$ECHO_BIN -e "\033[1m hosts\033[0m                        Displays cluster member nodes (dom0)"
        $ECHO_BIN -e "\033[1m locate\033[0m [resource]            Displays the status of the specified Xen cluster resource"
        $ECHO_BIN -e "\033[1m stop\033[0m [resource]              Stops the specified Xen cluster resource"
        $ECHO_BIN -e "\033[1m start\033[0m [resource]             Starts the specified Xen cluster resource"
	$ECHO_BIN -e "\033[1m standby\033[0m [node]               Puts the specified node into standby mode"
	$ECHO_BIN -e "\033[1m active\033[0m [node]                Puts the specified node back into active mode (standby off)"	
        $ECHO_BIN -e "\033[1m migrate\033[0m [resource] [node]    Migrates the Xen cluster resource to the specified host"
	$ECHO_BIN -e "\033[1m restore\033[0m [resource]           This function removes the constraints applied by \"migrate\" option."
    	$ECHO_BIN "                              Migration in HA stack is done by location constraints, scoring very"
	$ECHO_BIN "                              high to the preferred and very low to the non preferred node. This"
	$ECHO_BIN "                              feature will remove all \"migration\" applied interim constraints and"
	$ECHO_BIN "                              put the policy back to its initial state. You should run \"restore\""
	$ECHO_BIN "                              after \"migrate\" every time if you plan to leave the resource at the"
	$ECHO_BIN "                              new location."
	$ECHO_BIN
	$ECHO_BIN -e "\033[31mWARNING:\033[0m" "\"migrate\" option should be avoided, due to its nature modifying the location constraints."
	$ECHO_BIN "          If you need to free one of your nodes up (for scheduled maintenance, etc.) use \"standby\""
	$ECHO_BIN "          option instead."
        $ECHO_BIN
        exit 65
    }

# Set up variables according to given subcommand
case "$1" in
    list|hosts|locate|stop|start|migrate|restore)
	PARAM1=$1
	PARAM2=$2
	PARAM3=$3
	;;
    standby|active)
	PARAM1=$1
	PARAM3=$2
	;;
    *)
	usage_msg
	;;
esac

# This function is to validate the given parameter as domU name in the cluster
validate_domu() 
    {
      let MATCH=0
        for DOMU in ${DOMAINS}; do
          if [ "$DOMU" = "$PARAM2" ]; then
            let "MATCH = 1"
          fi
        done

        if [ ! "$MATCH" -eq 1 ]; then
          $ECHO_BIN "INVALID Xen cluster resource \"${PARAM2}\""
          exit 1
        fi
    }

# This function is to validate the given parameter as target host name in the cluster
validate_host() 
    {
      let MATCH=0
        for DOM0 in ${HOSTS}; do
	  if [ "$DOM0" = "$PARAM3" ]; then
            let "MATCH = 1"
	  fi
        done

      if [ ! "$MATCH" -eq 1 ]; then
        $ECHO_BIN "INVALID Xen cluster node \"${PARAM3}\""
        exit 1
      fi
    }

# This function is to evaluate the given parameter (target resource) againts exclusions
validate_exclusions() 
    {
      let MATCH=0
        for DOMU in $EXCLUDE; do
	  if [ "$DOMU" = "$PARAM2" ]; then
	    let "MATCH = 1"
	  fi
        done

      if [ "$MATCH" -eq 1 ]; then
	$ECHO_BIN "Xen cluster resource \"${PARAM2}\" must not be migrated"
	exit 1
      fi
    }

##---------END FUNCTIONS----------##

if [ $# -eq "1" ] && [ "$PARAM1" = "list" ]; then
    $CRM_RESOURCE -L | $GREP_BIN Xen

elif [ $# -eq "1" ] && [ "$PARAM1" = "hosts" ]; then
    $CRM_ADMIN -N

elif [ $# -eq "2" ] && [ "$PARAM1" = "locate" ] && [ $PARAM2 ]; then
    validate_domu
    $CRM_RESOURCE -W -r $PARAM2

elif [ $# -eq "2" ] && [ "$PARAM1" = "stop" ] && [ $PARAM2 ]; then
    validate_domu
    $CRM_RESOURCE -r $PARAM2 -p target_role -v stopped

elif [ $# -eq "2" ] && [ "$PARAM1" = "start" ] && [ $PARAM2 ]; then
    validate_domu
    $CRM_RESOURCE -r $PARAM2 -p target_role -v started

elif [ $# -eq "2" ] && [ "$PARAM1" = "standby" ] && [ $PARAM3 ]; then
    validate_host
    $CRM_STANDBY -U $PARAM3 -v on

elif [ $# -eq "2" ] && [ "$PARAM1" = "active" ] && [ $PARAM3 ]; then
    validate_host
    $CRM_STANDBY -U $PARAM3 -v off 
#    $CRM_STANDBY -D -U $PARAM3

elif [ $# -eq "3" ] && [ "$PARAM1" = "migrate" ] && [ $PARAM2 ] && [ $PARAM3 ]; then
    validate_domu
    validate_exclusions
    validate_host
    $CRM_RESOURCE -f -M -Q -r $PARAM2 -H $PARAM3

elif [ $# -eq "2" ] && [ "$PARAM1" = "restore" ] && [ $PARAM2 ]; then
    validate_domu
    $CRM_RESOURCE -U -r $PARAM2

else
    usage_msg
fi