[Lxc-users] [PATCH 1/1] Add lxc-clone script
Serge E. Hallyn
serge at hallyn.com
Tue Jun 21 19:05:48 UTC 2011
Create an lxc-clone script to clone containers. It should probably
be factored into helpers and then enhanced, in particular to convert
between LVM and non-LVM containers, create non-snapshot LVM clones,
support loopback devices, and, when stable enough, to use
overlayfs, btrfs, etc.
But this is a start.
Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
---
configure.ac | 1 +
lxc.spec.in | 1 +
src/lxc/Makefile.am | 1 +
src/lxc/lxc-clone.in | 208 ++++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 211 insertions(+), 0 deletions(-)
create mode 100644 src/lxc/lxc-clone.in
diff --git a/configure.ac b/configure.ac
index 6cce1b4..0d4f4c0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -157,6 +157,7 @@ AC_CONFIG_FILES([
src/lxc/lxc-setuid
src/lxc/lxc-version
src/lxc/lxc-create
+ src/lxc/lxc-clone
src/lxc/lxc-destroy
])
diff --git a/lxc.spec.in b/lxc.spec.in
index 452493d..f22cd06 100644
--- a/lxc.spec.in
+++ b/lxc.spec.in
@@ -78,6 +78,7 @@ rm -rf %{buildroot}
%{_bindir}/*
%attr(4111,root,root) %{_bindir}/lxc-attach
%attr(4111,root,root) %{_bindir}/lxc-create
+%attr(4111,root,root) %{_bindir}/lxc-clone
%attr(4111,root,root) %{_bindir}/lxc-start
%attr(4111,root,root) %{_bindir}/lxc-netstat
%attr(4111,root,root) %{_bindir}/lxc-unshare
diff --git a/src/lxc/Makefile.am b/src/lxc/Makefile.am
index 9def453..1dfca00 100644
--- a/src/lxc/Makefile.am
+++ b/src/lxc/Makefile.am
@@ -70,6 +70,7 @@ bin_SCRIPTS = \
lxc-setuid \
lxc-version \
lxc-create \
+ lxc-clone \
lxc-destroy
bin_PROGRAMS = \
diff --git a/src/lxc/lxc-clone.in b/src/lxc/lxc-clone.in
new file mode 100644
index 0000000..91944a0
--- /dev/null
+++ b/src/lxc/lxc-clone.in
@@ -0,0 +1,208 @@
+#!/bin/bash
+
+#
+# lxc: linux Container library
+
+# Authors:
+# Serge Hallyn <serge.hallyn at ubuntu.com>
+# Daniel Lezcano <daniel.lezcano at free.fr>
+
+# 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_size=2G
+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 "'$lxc_new' already exists"
+ exit 1
+fi
+
+trap "${bindir}/lxc-destroy -n $lxc_new; echo aborted; exit 1" SIGHUP SIGINT SIGTERM
+
+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
+
+sed -i '/lxc.mount/d' $lxc_path/$lxc_new/config
+echo "lxc.mount = $lxc_path/$lxc_new/fstab" >> $lxc_path/$lxc_new/config
+
+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
+
+echo "Copying rootfs..."
+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 '}`
+if [ -b $oldroot ]; then
+ # 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
+ lvcreate -s -L $lxc_size -n $lxc_new /dev/$lxc_vg/$lxc_orig || exit 1
+ echo "lxc.rootfs = /dev/$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"; exit 1; }
+ mounted=1
+else
+ cp -a $lxc_path/$lxc_orig/rootfs $lxc_path/$lxc_new/rootfs || return 1
+ echo "lxc.rootfs = $rootfs" >> $lxc_path/$lxc_new/config
+fi
+
+echo "Updating rootfs..."
+hostname=$lxc_new
+
+# so you can 'ssh $hostname.' or 'ssh $hostname.local'
+if [ -f $rootfs/etc/dhcp/dhclient.conf ]; then
+ sed -i "s/send host-name.*$/send host-name $hostname/" $rootfs/etc/dhcp/dhclient.conf
+fi
+
+# 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"
--
1.7.4.1
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