#!/bin/sh
#
# 
# LVM
#
# Description:	Manages an LVM volume as an HA resource
#
#
# Author:	Alan Robertson
# Support:	linux-ha@lists.linux-ha.org
# License:	GNU General Public License (GPL)
# Copyright:	(C) 2002 - 2005 International Business Machines, Inc.
#
#	This code significantly inspired by the LVM resource
#	in FailSafe by Lars Marowsky-Bree
#
#
# An example usage in /etc/ha.d/haresources: 
#       node1  10.0.0.170 ServeRAID::1::1 LVM::myvolname
#
# See usage() function below for more details...
#
#	  OCF parameters are as below:
#		OCF_RESKEY_volgrpname
#		
#######################################################################
# Initialization:

. ${OCF_ROOT}/resource.d/heartbeat/.ocf-shellfuncs

#######################################################################


usage() {
  methods=`LVM_methods`
  methods=`echo $methods | tr ' ' '|'`
  cat <<-!
	usage: $0 $methods

	$0 manages an  Linux Volume Manager volume (LVM) as an HA resource

	The 'start' operation brings the given volume online
	The 'stop' operation takes the given volume offline
	The 'status' operation reports whether the volume is available
	The 'monitor' operation reports whether the volume seems present
	The 'validate-all' operation checks whether the OCF parameters are valid
	The 'methods' operation reports on the methods $0 supports

	!
  exit $OCF_ERR_GENERIC 

}

meta_data() {
	cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="LVM">
<version>1.0</version>

<longdesc lang="en">
Resource script for LVM. It manages an  Linux Volume Manager volume (LVM) 
as an HA resource. 
</longdesc>
<shortdesc lang="en">LVM resource agent</shortdesc>

<parameters>
<parameter name="volgrpname" unique="0" required="1">
<longdesc lang="en">
The name of volume group.
</longdesc>
<shortdesc lang="en">Volume group name</shortdesc>
<content type="string" default="" />
</parameter>
</parameters>

<actions>
<action name="start" timeout="30" />
<action name="stop" timeout="30" />
<action name="status" timeout="30" />
<action name="monitor" depth="0" timeout="30" interval="10" start-delay="10" />
<action name="methods" timeout="5" />
<action name="meta-data" timeout="5" />
<action name="validate-all" timeout="5" />
</actions>
</resource-agent>
END
}

#
# methods: What methods/operations do we support?
#
LVM_methods() {
  cat <<-!
	start
	stop
	status
	monitor
	methods
	validate-all
	usage
	!
}

#
#	Return LVM status (silently)
#
LVM_status() {

  if 
    [ "$LVM_MAJOR" -eq "1" ]
  then
	vgdisplay $1 | grep -i 'Status.*available' >/dev/null
	return $?
  else
	vgdisplay -v $1 | grep -i 'Status[ \t]*available' >/dev/null
	return $?
  fi
  
}

#
#	Report on LVM volume status to stdout...
#
LVM_report_status() {

  if 
    [ "$LVM_MAJOR" -eq "1" ]
  then
	VGOUT=`vgdisplay $1 2>&1`
	echo "$VGOUT" | grep -i 'Status.*available' >/dev/null
	rc=$?
  else
	VGOUT=`vgdisplay -v $1 2>&1`
	echo "$VGOUT" | grep -i 'Status[ \t]*available' >/dev/null
	rc=$?
  fi

  if
    [ $rc -eq 0 ]
  then
    : Volume $1 is available
  else
    ocf_log debug "LVM Volume $1 is not available (stopped)"
    return $OCF_NOT_RUNNING
  fi

  if
    echo "$VGOUT" | grep -i 'Access.*read/write' >/dev/null
  then
    ocf_log debug "Volume $1 is available read/write (running)"
  else
    ocf_log debug "Volume $1 is available read-only (running)"
  fi
  
  return $OCF_SUCCESS
}

#
#	Monitor the volume - does it really seem to be working?
#
#
LVM_monitor() {

  if
    LVM_status $1
  then
    : OK
  else
    ocf_log info "LVM Volume $1 is offline"
    return $OCF_NOT_RUNNING
  fi

  ocf_run vgck $1

  return $?
}

#
#	Enable LVM volume
#
LVM_start() {

  # TODO: This MUST run vgimport as well

  ocf_log info "Activating volume group $1"

  if 
    [ "$LVM_MAJOR" -eq "1" ]
  then
	ocf_run vgscan $1
  else
	ocf_run vgscan
  fi

  # TODO: For v2, this MUST use --refresh
  ocf_run vgchange -a y $1 || return $OCF_ERR_GENERIC

  if
    LVM_status $1
  then
    : OK Volume $1 activated just fine!
    return $OCF_SUCCESS 
  else
    ocf_log err "LVM: $1 did not activate correctly"
    return $OCF_ERR_GENERIC
  fi
}

#
#	Disable the LVM volume
#
LVM_stop() {

  ocf_log info "Deactivating volume group $1"
  ocf_run vgchange -a n $1 || return 1

  if
    LVM_status $1
  then
    ocf_log err "LVM: $1 did not stop correctly"
    return $OCF_ERR_GENERIC 
  fi

  # TODO: This MUST run vgexport as well

  return $OCF_SUCCESS
}

#
#	Check whether the OCF instance parameters are valid
#
LVM_validate_all() {
  check_binary $AWK

#	Off-the-shelf tests...  
  vgck "$VOLUME" >/dev/nulll 2>&1
  
  if [ $? -ne 0 ]; then
	ocf_log err "Volume group [$VOLUME] does not exist or contains error!"
	exit $OCF_ERR_GENERIC
  fi

#	Double-check
  if 
    [ "$LVM_MAJOR" -eq "1" ]
  then
	vgdisplay "$VOLUME" >/dev/null 2>&1
  else
	vgdisplay -v "$VOLUME" >/dev/null 2>&1
  fi

  if [ $? -ne 0 ]; then
	ocf_log err "Volume group [$VOLUME] does not exist or contains error!"
	exit $OCF_ERR_GENERIC
  fi

  return $OCF_SUCCESS
}
#
#	'main' starts here...
#

if
  ( [ $# -ne 1 ] )
then
  usage
  exit $OCF_ERR_ARGS 
fi

case $1 in
  meta-data)	meta_data
		exit $OCF_SUCCESS;;

  methods)	LVM_methods
		exit $?;;

  usage)	usage
		exit $OCF_SUCCESS;;
  *)		;;
esac

if 
  [ -z "$OCF_RESKEY_volgrpname" ]
then
#  echo "You must identify the volume group name!"
  ocf_log err "You must identify the volume group name!"
#  usage
  exit $OCF_ERR_ARGS 
fi

# Get the LVM version number, for this to work we assume(thanks to panjiam):
# 
# LVM1 outputs like this
#
#	# vgchange --version
#	vgchange: Logical Volume Manager 1.0.3
#	Heinz Mauelshagen, Sistina Software  19/02/2002 (IOP 10)
#
# LVM2 and higher versions output in this format
#
#	# vgchange --version
#	LVM version:     2.00.15 (2004-04-19)
#	Library version: 1.00.09-ioctl (2004-03-31)
#	Driver version:  4.1.0

LVM_VERSION=`vgchange --version 2>&1 | \
	$AWK '/Logical Volume Manager/ {print $5"\n"; exit; }
	     /LVM version:/ {printf $3"\n"; exit;}'`
rc=$?

if
  ( [ $rc -ne 0 ] || [ -z "$LVM_VERSION" ] )
then
  ocf_log err "LVM: $1 could not determine LVM version. Try 'vgchange --version' manually and modify $0 ?"
  exit $OCF_ERR_GENERIC
fi
LVM_MAJOR="${LVM_VERSION%%.*}"

VOLUME=$OCF_RESKEY_volgrpname

# What kind of method was invoked?
case "$1" in

  start)	LVM_start $VOLUME
		exit $?;;

  stop)		LVM_stop $VOLUME
		exit $?;;

  status)	LVM_report_status $VOLUME
		exit $?;;

  monitor)	LVM_monitor $VOLUME
		exit $?;;

  validate-all)	LVM_validate_all
		;;

  *)		usage
		exit $OCF_ERR_AEGS;;
esac
