/usr/bin/lxc-clone

lxc-clone

#!/bin/bash

#
# lxc: linux Container library

# Authors:
# Serge Hallyn <[email protected]>
# Daniel Lezcano <[email protected]>

# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.

# This library 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
# Lesser General Public License for more details.

# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

usage() {
    echo "usage: lxc-clone -o <orig> -n <new> [-s] [-h] [-L fssize] [-v vgname]"
}

help() {
    usage
    echo
    echo "creates a lxc system object."
    echo
    echo "Options:"
    echo "orig        : name of the original container"
    echo "new         : name of the new container"
    echo "-s          : make the new rootfs a snapshot of the original"
    echo "fssize      : size if creating a new fs.  By default, 2G"
    echo "vgname      : lvm volume group name, lxc by default"
}

shortoptions='ho:n:sL:v:'
longoptions='help,orig:,name:,snapshot,fssize,vgname'
lxc_path=/var/lib/lxc
bindir=/usr/bin
snapshot=no
lxc_defsize=2G
lxc_size=_unset
lxc_vg=lxc

getopt=$(getopt -o $shortoptions --longoptions  $longoptions -- "$@")
if [ $? != 0 ]; then
    usage
    exit 1;
fi

eval set -- "$getopt"

while true; do
        case "$1" in
      -h|--help)
		help
		exit 1
		;;
	    -s|--snapshot)
		shift
		snapshot=yes
		;;
	    -o|--orig)
		shift
		lxc_orig=$1
		shift
		;;
	    -L|--fssize)
		shift
		lxc_size=$1
		shift
		;;
	    -v|--vgname)
		shift
		lxc_vg=$1
		shift
		;;
	    -n|--new)
		shift
		lxc_new=$1
		shift
		;;
            --)
		shift
		break;;
            *)
		echo $1
		usage
		exit 1
		;;
        esac
done

if [ -z "$lxc_path" ]; then
    echo "no configuration path defined !"
    exit 1
fi

if [ ! -r $lxc_path ]; then
    echo "configuration path '$lxc_path' not found"
    exit 1
fi

if [ -z "$lxc_orig" ]; then
    echo "no original container name specified"
    usage
    exit 1
fi

if [ -z "$lxc_new" ]; then
    echo "no new container name specified"
    usage
    exit 1
fi

if [ "$(id -u)" != "0" ]; then
   echo "This command has to be run as root"
   exit 1
fi

if [ ! -r $lxc_path ]; then
    echo "no configuration path defined !"
    exit 1
fi

if [ ! -d "$lxc_path/$lxc_orig" ]; then
    echo "'$lxc_orig' does not exist"
    exit 1
fi

if [ -d "$lxc_path/$lxc_new" ]; then
    echo "'$lxc_new' already exists"
    exit 1
fi

hostname=$lxc_new
mkdir -p $lxc_path/$lxc_new

echo "Tweaking configuration"
cp $lxc_path/$lxc_orig/config $lxc_path/$lxc_new/config
sed -i '/lxc.utsname/d' $lxc_path/$lxc_new/config
echo "lxc.utsname = $hostname" >> $lxc_path/$lxc_new/config

grep "lxc.mount[ \t]" $lxc_path/$lxc_new/config >/dev/null 2>&1 && { sed -i '/lxc.mount[ \t]/d' $lxc_path/$lxc_new/config; echo "lxc.mount = $lxc_path/$lxc_new/fstab" >> $lxc_path/$lxc_new/config; }

if [ -e  $lxc_path/$lxc_orig/fstab ];then
    cp $lxc_path/$lxc_orig/fstab $lxc_path/$lxc_new/fstab
    sed -i "s@$lxc_path/$lxc_orig@$lxc_path/$lxc_new@" $lxc_path/$lxc_new/fstab
fi

rootfs=$lxc_path/$lxc_new/rootfs
# First figure out if the old is a device.  For now we only support
# lvm devices.
mounted=0
sed -i '/lxc.rootfs/d' $lxc_path/$lxc_new/config
oldroot=`grep lxc.rootfs $lxc_path/$lxc_orig/config | awk -F= '{ print $2 '}`

cleanup() {
    if [ -b $oldroot ]; then
        if [ $mounted -eq 1 ]; then
            umount $rootfs
        fi
        lvremove -f $rootdev
    fi
    ${bindir}/lxc-destroy -n $lxc_new
    echo aborted
    exit 1
}
trap cleanup SIGHUP SIGINT SIGTERM

echo "Copying rootfs..."
if [ -b $oldroot ]; then
    which vgscan > /dev/null
    if [ $? -ne 0 ]; then
        echo "vgscan not found.  Please install lvm2 package"
        exit 1
    fi

	# this is a device.  If we don't want to snapshot, then mkfs, mount
	# and rsync.  Trivial but not yet implemented
	if [ $snapshot == "no" ]; then
		echo "non-snapshot and non-lvm clone of block device not yet implemented"
		exit 1
	fi
	lvdisplay $oldroot > /dev/null 2>&1
	if [ $? -ne 0 ]; then
		echo "non-snapshot and non-lvm clone of block device not yet implemented"
		exit 1
	fi
	# ok, create a snapshot of the lvm device
	if [ $lxc_size = "_unset" ]; then
		lxc_size=`lvdisplay $oldroot | grep Size | awk '{ print $3 $4 }'`
	fi
	lvcreate -s -L $lxc_size -n $lxc_new /dev/$lxc_vg/$lxc_orig || cleanup
	echo "lxc.rootfs = /dev/$lxc_vg/$lxc_new" >> $lxc_path/$lxc_new/config
	# and mount it so we can tweak it
	mkdir -p $lxc_path/$lxc_new/rootfs
	mount /dev/$lxc_vg/$lxc_new $rootfs || { echo "failed to mount new rootfs"; cleanup; }
	mounted=1
elif out=$(btrfs subvolume list "$lxc_path/$lxc_orig/rootfs" 2>&1); then
	out=$(btrfs subvolume snapshot "$lxc_path/$lxc_orig/rootfs" "$rootfs" 2>&1)
	if [ $? -ne 0 ]; then
		echo "failed btrfs subvolume snapshot of $lxc_path/$lxc_orig/rootfs"
		cleanup
	fi
	echo "lxc.rootfs = $rootfs" >> "$lxc_path/$lxc_new/config"
else
	cp -a $lxc_path/$lxc_orig/rootfs $lxc_path/$lxc_new/rootfs || cleanup
	echo "lxc.rootfs = $rootfs" >> $lxc_path/$lxc_new/config
fi

echo "Updating rootfs..."

# so you can 'ssh $hostname.' or 'ssh $hostname.local'
if [ -f $rootfs/etc/dhcp/dhclient.conf ] && ! grep -q "^send host-name.*hostname" $rootfs/etc/dhcp/dhclient.conf; then
	sed -i "s/send host-name.*$/send host-name $hostname;/" $rootfs/etc/dhcp/dhclient.conf
fi

c=$lxc_path/$lxc_new/config
# change hwaddrs
mv ${c} ${c}.old
(
while read line; do
	if [ "${line:0:18}" = "lxc.network.hwaddr" ]; then
		echo "lxc.network.hwaddr= 00:16:3e:$(openssl rand -hex 3| sed 's/\(..\)/\1:/g; s/.$//')"
	else
		echo "$line"
	fi
done
) < ${c}.old > ${c}
rm -f ${c}.old

# set the hostname
cat <<EOF > $rootfs/etc/hostname
$hostname
EOF
# set minimal hosts
cat <<EOF > $rootfs/etc/hosts
127.0.0.1 localhost $hostname
EOF

# if this was a block device, then umount it now
if [ $mounted -eq 1 ]; then
	umount $rootfs
fi

echo "'$lxc_new' created"