#!/bin/sh
# Copyright (C) 2000-2007 SWsoft. All rights reserved.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#
# vzmigrate is used for VE migration to another node
#
# Usage:
# vzmigrate [-r yes|no] [--ssh=<options>] [--keep-dst] [--online] [-v]
#           destination_address VEID
# Options:
#	-r, --remove-area yes|no
#		Whether to remove VE on source HN for successfully migrated VE.
#	--ssh=<ssh options>
#		Additional options that will be passed to ssh while establishing
#		connection to destination HN. Please be careful with options
#		passed, DO NOT pass destination hostname.
#	--keep-dst
#		Do not clean synced destination VE private area in case of some
#		error. It makes sense to use this option on big VE migration to
#		avoid syncing VE private area again in case some error
#		(on VE stop for example) occurs during first migration attempt.
#	--online
#		Perform online (zero-downtime) migration: during the migration the
#		VE hangs for a while and after the migration it continues working
#		as though nothing has happened.
#	-v
#		Verbose mode. Causes vzmigrate to print debugging messages about
#		its progress (including some time statistics).
#
# Examples:
#	Online migration of VE #101 to foo.com:
#		vzmigrate --online foo.com 101
#	Migration of VE #102 to foo.com with downtime:
#		vzmigrate foo.com 102
# NOTE:
#	This program uses ssh as a transport layer. You need to put ssh
#	public key to destination node and be able to connect without
#	entering a password.


ACT_SCRIPTS_SFX="start stop mount umount"
SSH_OPTIONS=""
SSH="ssh $SSH_OPTIONS"
SCP_OPTIONS=""
SCP="scp $SCP_OPTIONS"
RSYNC_OPTIONS="-aH --delete --numeric-ids"
RSYNC="rsync $RSYNC_OPTIONS"

online=0
verbose=0
remove_area=1
keep_dst=0
debug=0
confdir="@PKGCONFDIR@/conf"
vzconf="@PKGCONFDIR@/vz.conf"
tmpdir="/var/tmp"
act_scripts=

# Errors:
MIG_ERR_USAGE=1
MIG_ERR_VPS_IS_STOPPED=2
MIG_ERR_CANT_CONNECT=4
MIG_ERR_COPY=6
MIG_ERR_START_VPS=7
MIG_ERR_STOP_SOURCE=8
MIG_ERR_EXISTS=9
MIG_ERR_NOEXIST=10
MIG_ERR_IP_IN_USE=12
MIG_ERR_QUOTA=13
MIG_ERR_CHECKPOINT=$MIG_ERR_STOP_SOURCE
MIG_ERR_MOUNT_VPS=$MIG_ERR_START_VPS
MIG_ERR_RESTORE_VPS=$MIG_ERR_START_VPS
MIG_ERR_OVZ_NOT_RUNNING=14
MIG_ERR_APPLY_CONFIG=15

usage() {
	cat >&2 <<EOF
This program is used for VE migration to another node
Usage:
vzmigrate [-r yes|no] [--ssh=<options>] [--keep-dst] [--online] [-v]
	destination_address <VEID>
Options:
-r, --remove-area yes|no
	Whether to remove VE on source HN for successfully migrated VE.
--ssh=<ssh options>
	Additional options that will be passed to ssh while establishing
	connection to destination HN. Please be careful with options
	passed, DO NOT pass destination hostname.
--keep-dst
	Do not clean synced destination VE private area in case of some
	error. It makes sense to use this option on big VE migration to
	avoid syncing VE private area again in case some error
	(on VE stop for example) occurs during first migration attempt.
--online
	Perform online (zero-downtime) migration: during the migration the
	VE hangs for a while and after the migration it continues working
	as though nothing has happened.
-v
	Verbose mode. Causes vzmigrate to print debugging messages about
	its progress (including some time statistics).
EOF
	exit $MIG_ERR_USAGE
}

# Logs message
# There are 3 types of messages:
# 0 - error messages (print to stderr)
# 1 - normal messages (print to stdout)
# 2 - debug messages (print to stdout if in verbose mode)
log () {
	if [ $1 -eq 0 ]; then
		shift
		echo -e "Error: " $@ >&2
	elif [ $1 -eq 1 ]; then
		shift
		echo -e $@
	elif [ $verbose -eq 1 ]; then
		shift
		echo -e "   " $@
	fi
}

# Executes command and returns result of execution
# There are 2 types of execution:
# 1 - normal execution (all output will be printed)
# 2 - debug execution (output will be printed if verbose mode is set,
#     in other case stdout and stderr redirected to /dev/null)
logexec () {
	if [ $1 -eq 1 -o $verbose -eq 1 ]; then
		shift
		$@
	else
		shift
		$@ >/dev/null 2>&1
	fi
}

undo_conf () {
	$SSH "root@$host" "rm -f $vpsconf"
}

undo_act_scripts () {
	if [ -n "$act_scripts" ] ; then
		$SSH "root@$host" "rm -f $act_scripts"
	fi
	undo_conf
}

undo_private () {
	if [ $keep_dst -eq 0 ]; then
		$SSH "root@$host" "rm -rf $VE_PRIVATE"
	fi
	undo_act_scripts
}

undo_root () {
	$SSH "root@$host" "rm -rf $VE_ROOT"
	undo_private
}

undo_quota_init () {
	[ "${DISK_QUOTA}" = 'no' ] || $SSH "root@$host" "vzquota drop $VEID"
	undo_root
}

undo_quota_on () {
	[ "${DISK_QUOTA}" = 'no' ] || $SSH "root@$host" "vzquota off $VEID"
	undo_quota_init
}

undo_sync () {
	# Root will be destroed in undo_root
	undo_quota_on
}

undo_suspend () {
	logexec 2 vzctl chkpnt $VEID --resume
	undo_sync
}

undo_dump () {
	if [ $debug -eq 0 ]; then
		rm -f "$VE_DUMPFILE"
	fi
	undo_suspend
}

undo_copy_dump () {
	$SSH "root@$host" "rm -f $VE_DUMPFILE"
	undo_suspend
}

undo_stop () {
	if [ "$state" = "running" ]; then
		vzctl start $VEID
	elif [ "$mounted" = "mounted" ]; then
		vzctl mount $VEID
	fi
	undo_sync
}

undo_source_stage() {
	if [ $online -eq 1 ]; then
		undo_copy_dump
	else
		undo_stop
	fi
}

undo_quota_dump () {
	rm -f "$VE_QUOTADUMP"
	undo_source_stage
}

undo_copy_quota () {
	$SSH "root@$host" "rm -f $VE_QUOTADUMP"
	undo_quota_dump
}

undo_undump () {
	logexec 2 $SSH root@$host vzctl restore $VEID --kill
	undo_copy_quota
}

get_status() {
	exist=$3
	mounted=$4
	state=$5
}

get_time () {
	awk -v t2=$2 -v t1=$1 'BEGIN{print t2-t1}'
}

if [ $# -lt 2 ]; then
	usage
fi

while [ ! -z "$1" ]; do
	log 1 "OPT:$1"
	case "$1" in
	--online)
		online=1
		;;
	-v)
		verbose=1
		;;
	--remove-area|-r)
		shift
		if [ "$1" = "yes" ]; then
			remove_area=1
		elif [ "$1" = "no" ]; then
			remove_area=0
		else
			usage
		fi
		;;
	--keep-dst)
		keep_dst=1
		;;
	--ssh=*)
		SSH_OPTIONS="$SSH_OPTIONS $(echo $1 | cut -c7-)"
		SSH="ssh $SSH_OPTIONS"
		SCP_OPTIONS="`echo $SSH_OPTIONS | sed 's/-p/-P/1'`"
		SCP="scp $SCP_OPTIONS"
		;;
	*)
		break
		;;
	esac
	shift
done

host=$1
shift
VEID=$1
shift

if [ -z "$host" -o -z "$VEID" -o $# -ne 0 ]; then
	usage
fi

vpsconf="$confdir/$VEID.conf"

if [ ! -r "$vzconf" -o ! -r "$vpsconf" ]; then
	log 0 "Can't read global config or VE #$VEID config file"
	exit $MIG_ERR_NOEXIST
fi

get_status $(vzctl status $VEID)
if [ "$exist" = "deleted" ]; then
	log 0 "VE #$VEID doesn't exist"
	exit $MIG_ERR_NOEXIST
fi

if [ $online -eq 1 ]; then
	log 1 "Starting online migration of VE $VEID on $host"
else
	log 1 "Starting migration of VE $VEID on $host"
fi

# Try to connect to destination
if ! logexec 2 $SSH -o BatchMode=yes root@$host /bin/true; then
	log 0 "Can't connect to destination address using public key"
	log 0 "Please put your public key to destination node"
	exit $MIG_ERR_CANT_CONNECT
fi

# Check if OpenVZ is running
if ! logexec 2 $SSH -o BatchMode=yes root@$host /etc/init.d/vz status ; then
	log 0 "OpenVZ is not running on the target machine"
	log 0 "Can't continue migration"
	exit $MIG_ERR_OVZ_NOT_RUNNING
fi

# Check if CPT modules are loaded for online migration
if [ $online -eq 1 ]; then
	if [ ! -f /proc/cpt ]; then
		log 0 "vzcpt module is not loaded on the source node"
		log 0 "Can't continue online migration"
		exit $MIG_ERR_OVZ_NOT_RUNNING
	fi
	if ! logexec 2 $SSH -o BatchMode=yes root@$host "test -f /proc/rst";
	then
		log 0 "vzrst module is not loaded on the destination node"
		log 0 "Can't continue online migration"
		exit $MIG_ERR_OVZ_NOT_RUNNING
	fi
fi

dst_exist=$($SSH "root@$host" "vzctl status $VEID" | awk '{print $3}')
if [ "$dst_exist" = "exist" ]; then
	log 0 "VE #$VEID already exists on destination node"
	exit $MIG_ERR_EXISTS
fi

if [ $online -eq 1 -a "$state" != "running" ]; then
	log 0 "Can't perform online migration of stopped VE"
	exit $MIG_ERR_VPS_IS_STOPPED
fi

log 2 "Loading $vzconf and $vpsconf files"

. "$vzconf"
. "$vpsconf"
VE_DUMPFILE="$tmpdir/dump.$VEID"
VE_QUOTADUMP="$tmpdir/quotadump.$VEID"

log 2 "Check IPs on destination node: $IP_ADDRESS"
for IP in $IP_ADDRESS; do
	if [ $($SSH "root@$host" "grep -c \" $IP \" /proc/vz/veip") -gt 0 ];
	then
		log 0 "IP address $IP already in use on destination node"
		exit $MIG_ERR_IP_IN_USE
	fi
done

log 1 "Preparing remote node"

log 2 "Copying config file"
if ! logexec 2 $SCP $vpsconf root@$host:$vpsconf ; then
	log 0 "Failed to copy config file"
	exit $MIG_ERR_COPY
fi

logexec 2 $SSH root@$host vzctl set $VEID --applyconfig_map name --save
# vzctl return code 20 or 21 in case of unrecognized option
if [ $? != 20 && $? != 21 && $? != 0 ]; then
	log 0 "Failed to apply config on destination node"
	undo_conf
	exit $MIG_ERR_APPLY_CONFIG
fi

for sfx in $ACT_SCRIPTS_SFX; do
	file="$confdir/$VEID.$sfx"
	if [ -f "$file" ]; then
		act_scripts="$act_scripts $file"
	fi
done
if [ -n "$act_scripts" ]; then
	log 2 "Copying action scripts"
	if ! logexec 2 $SCP $act_scripts root@$host:$confdir ; then
		log 0 "Failed to copy action scripts"
		undo_conf
		exit $MIG_ERR_COPY
	fi
fi

log 2 "Creating remote VE root dir"
if ! $SSH "root@$host" "mkdir -p $VE_ROOT"; then
	log 0 "Failed to make VE root"
	undo_act_scripts
	exit $MIG_ERR_COPY
fi

log 2 "Creating remote VE private dir"
if ! $SSH "root@$host" "mkdir -p $VE_PRIVATE"; then
	log 0 "Failed to make VE private area"
	undo_private
	exit $MIG_ERR_COPY
fi

if [ "${DISK_QUOTA}" != "no" ]; then
	log 1 "Initializing remote quota"

	log 2 "Quota init"
	if ! $SSH "root@$host" "vzctl quotainit $VEID"; then
		log 0 "Failed to initialize quota"
		undo_root
		exit $MIG_ERR_QUOTA
	fi

	log 2 "Turning remote quota on"
	if ! $SSH "root@$host" "vzctl quotaon $VEID"; then
		log 0 "Failed to turn quota on"
		undo_quota_init
		exit $MIG_ERR_QUOTA
	fi
else
	log 2 "VZ disk quota disabled -- skipping quota migration"
fi

log 1 "Syncing private"
if ! $RSYNC --progress \
		"$VE_PRIVATE" "root@$host:${VE_PRIVATE%/*}" |
		grep "% of" | awk -v ORS="\r" '{print $10}'; then
	log 0 "Failed to sync VE private areas"
	undo_quota_on
	exit $MIG_ERR_COPY
fi

if [ $online -eq 1 ]; then
	log 1 "Live migrating VE"

	log 2 "Suspending VE"
	time_suspend=$(date +%s.%N)
	if ! logexec 2 vzctl chkpnt $VEID --suspend ; then
		log 0 "Failed to suspend VE"
		undo_sync
		exit $MIG_ERR_CHECKPOINT
	fi

	log 2 "Dumping VE"
	if ! logexec 2 vzctl chkpnt $VEID --dump --dumpfile $VE_DUMPFILE ; then
		log 0 "Failed to dump VE"
		undo_suspend
		exit $MIG_ERR_CHECKPOINT
	fi

	log 2 "Copying dumpfile"
	time_copy_dump=$(date +%s.%N)
	if ! logexec 2 $SCP $VE_DUMPFILE root@$host:$VE_DUMPFILE ; then
		log 0 "Failed to copy dump"
		undo_dump
		exit $MIG_ERR_COPY
	fi
else
	if [ "$state" = "running" ]; then
		log 1 "Stopping VE"
		if ! logexec 2 vzctl stop $VEID ; then
			log 0 "Failed to stop VE"
			undo_sync
			exit $MIG_ERR_STOP_SOURCE
		fi
	elif [ "$mounted" = "mounted" ]; then
		log 1 "Unmounting VE"
		if ! logexec 2 vzctl umount $VEID ; then
			log 0 "Failed to umount VE"
			undo_sync
			exit $MIG_ERR_STOP_SOURCE
		fi
	fi
fi

if [ "$state" = "running" ]; then
	log 2 "Syncing private (2nd pass)"
	time_rsync2=$(date +%s.%N)
	if ! $RSYNC \
			"$VE_PRIVATE" "root@$host:${VE_PRIVATE%/*}"; then
		log 0 "Failed to sync VE private areas"
		undo_source_stage
		exit $MIG_ERR_COPY
	fi
fi

if [ "${DISK_QUOTA}" != "no" ]; then
	log 1 "Syncing 2nd level quota"

	log 2 "Dumping 2nd level quota"
	time_quota=$(date +%s.%N)
	if ! vzdqdump $VEID -U -G -T > "$VE_QUOTADUMP"; then
		log 0 "Failed to dump 2nd level quota"
		undo_quota_dump
		exit $MIG_ERR_QUOTA
	fi

	log 2 "Copying 2nd level quota"
	if ! logexec 2 $SCP $VE_QUOTADUMP root@$host:$VE_QUOTADUMP ; then
		log 0 "Failed to copy 2nd level quota dump"
		undo_quota_dump
		exit $MIG_ERR_COPY
	fi

	log 2 "Load 2nd level quota"
	if ! $SSH "root@$host" "(vzdqload $VEID -U -G -T < $VE_QUOTADUMP &&
			vzquota reload2 $VEID)"; then
		log 0 "Failed to load 2nd level quota"
		undo_copy_quota
		exit $MIG_ERR_QUOTA
	fi
else
	log 2 "VZ disk quota disabled -- skipping quota migration"
fi

if [ $online -eq 1 ]; then
	log 2 "Undumping VE"
	time_undump=$(date +%s.%N)
	if ! logexec 2 $SSH root@$host vzctl restore $VEID --undump \
			--dumpfile $VE_DUMPFILE --skip_arpdetect ; then
		log 0 "Failed to undump VE"
		undo_copy_quota
		exit $MIG_ERR_RESTORE_VPS
	fi

	log 2 "Resuming VE"
	if ! logexec 2 $SSH root@$host vzctl restore $VEID --resume ; then
		log 0 "Failed to resume VE"
		undo_undump
		exit $MIG_ERR_RESTORE_VPS
	fi
	time_finish=$(date +%s.%N)
	log 2 "Times:"
	log 2 "\tSuspend + Dump:\t" $(get_time $time_suspend $time_copy_dump)
	log 2 "\tCopy dump file:\t" $(get_time $time_copy_dump $time_rsync2)
	log 2 "\tSecond rsync:\t" $(get_time $time_rsync2 $time_quota)
	log 2 "\t2nd level quota:\t" $(get_time $time_quota $time_undump)
	log 2 "\tUndump + Resume:\t" $(get_time $time_undump $time_finish)
	log 2 "Total time: " $(get_time $time_suspend $time_finish)

	log 1 "Cleanup"

	log 2 "Killing VE"
	logexec 2 vzctl chkpnt $VEID --kill
	logexec 2 vzctl umount $VEID

	log 2 "Removing dumpfiles"
	rm -f "$VE_DUMPFILE"
	$SSH "root@$host" "rm -f $VE_DUMPFILE"
else
	if [ "$state" = "running" ]; then
		log 1 "Starting VE"
		if ! logexec 2 $SSH root@$host vzctl start $VEID ; then
			log 0 "Failed to start VE"
			undo_copy_quota
			exit $MIG_ERR_START_VPS
		fi
	elif [ "$mounted" = "mounted" ]; then
		log 1 "Mounting VE"
		if ! logexec 2 $SSH root@$host vzctl mount $VEID ; then
			log 0 "Failed to mount VE"
			undo_copy_quota
			exit $MIG_ERR_MOUNT_VPS
		fi
	else
		log 1 "Turning quota off"
		if ! logexec 2 $SSH root@$host vzquota off $VEID ; then
			log 0 "failed to turn quota off"
			undo_copy_quota
			exit $MIG_ERR_QUOTA
		fi
	fi

	log 1 "Cleanup"
fi

if [ $remove_area -eq 1 ]; then
	log 2 "Destroying VE"
	logexec 2 vzctl destroy $VEID
else
	# Move config as veid.migrated to allow backward migration
	mv -f $vpsconf $vpsconf.migrated
fi
