[lxc-devel] [PATCH v2 1/2] add clonehostname hook

Stéphane Graber stgraber at ubuntu.com
Tue Jul 9 20:22:17 UTC 2013


On Tue, Jul 09, 2013 at 04:19:45PM -0400, Dwight Engen wrote:
> This hook script updates the hostname in various files under /etc in the
> cloned container. In order to do so, the old container name is passed in
> the LXC_SRC_NAME environment variable.
> 
> Signed-off-by: Dwight Engen <dwight.engen at oracle.com>

Looks good.

Acked-by: Stéphane Graber <stgraber at ubuntu.com>

> ---
>  doc/lxc-clone.sgml.in  |  3 ++-
>  hooks/Makefile.am      |  1 +
>  hooks/clonehostname    | 29 +++++++++++++++++++++++++++++
>  src/lxc/lxccontainer.c |  9 +++++++--
>  4 files changed, 39 insertions(+), 3 deletions(-)
>  create mode 100755 hooks/clonehostname
> 
> diff --git a/doc/lxc-clone.sgml.in b/doc/lxc-clone.sgml.in
> index 6885ff7..74982a1 100644
> --- a/doc/lxc-clone.sgml.in
> +++ b/doc/lxc-clone.sgml.in
> @@ -255,7 +255,8 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
>        argument 4.  The <filename>LXC_ROOTFS_MOUNT</filename> environment variable gives
>        the path under which the container's root filesystem is mounted.  The
>        configuration file pathname is stored in <filename>LXC_CONFIG_FILE</filename>, the
> -      container name in <filename>LXC_NAME</filename>, and the path or device on which
> +      new container name in <filename>LXC_NAME</filename>, the old container name in
> +      <filename>LXC_SRC_NAME</filename>, and the path or device on which
>        the rootfs is located is in <filename>LXC_ROOTFS_PATH</filename>.
>      </para>
>    </refsect1>
> diff --git a/hooks/Makefile.am b/hooks/Makefile.am
> index 196e632..3e32ce0 100644
> --- a/hooks/Makefile.am
> +++ b/hooks/Makefile.am
> @@ -1,6 +1,7 @@
>  hooksdir=@LXCHOOKDIR@
>  
>  hooks_SCRIPTS = \
> +	clonehostname \
>  	mountcgroups \
>  	mountecryptfsroot
>  
> diff --git a/hooks/clonehostname b/hooks/clonehostname
> new file mode 100755
> index 0000000..8865c2d
> --- /dev/null
> +++ b/hooks/clonehostname
> @@ -0,0 +1,29 @@
> +#!/bin/sh
> +#
> +# Update the hostname in the cloned container's scripts
> +#
> +# Copyright ©  2013 Oracle.
> +#
> +# This library is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License version 2, as
> +# published by the Free Software Foundation.
> +#
> +# 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.,
> +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
> +
> +# Note that /etc/hostname is updated by lxc itself
> +for file in \
> +    $LXC_ROOTFS_PATH/etc/sysconfig/network \
> +    $LXC_ROOTFS_PATH/etc/sysconfig/network-scripts/ifcfg-* ;
> +do
> +    if [ -f $file ]; then
> +        sed -i "s|$LXC_SRC_NAME|$LXC_NAME|" $file
> +    fi
> +done
> +exit 0
> diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
> index 4e71fb1..4dbb587 100644
> --- a/src/lxc/lxccontainer.c
> +++ b/src/lxc/lxccontainer.c
> @@ -1767,7 +1767,9 @@ static int copy_storage(struct lxc_container *c0, struct lxc_container *c,
>  	return 0;
>  }
>  
> -static int clone_update_rootfs(struct lxc_container *c, int flags, char **hookargs)
> +static int clone_update_rootfs(struct lxc_container *c0,
> +			       struct lxc_container *c, int flags,
> +			       char **hookargs)
>  {
>  	int ret = -1;
>  	char path[MAXPATHLEN];
> @@ -1797,6 +1799,9 @@ static int clone_update_rootfs(struct lxc_container *c, int flags, char **hookar
>  
>  	if (!lxc_list_empty(&conf->hooks[LXCHOOK_CLONE])) {
>  		/* Start of environment variable setup for hooks */
> +		if (setenv("LXC_SRC_NAME", c0->name, 1)) {
> +			SYSERROR("failed to set environment variable for source container name");
> +		}
>  		if (setenv("LXC_NAME", c->name, 1)) {
>  			SYSERROR("failed to set environment variable for container name");
>  		}
> @@ -1955,7 +1960,7 @@ struct lxc_container *lxcapi_clone(struct lxc_container *c, const char *newname,
>  	if (!c2->save_config(c2, NULL))
>  		goto out;
>  
> -	if (clone_update_rootfs(c2, flags, hookargs) < 0)
> +	if (clone_update_rootfs(c, c2, flags, hookargs) < 0)
>  		goto out;
>  
>  	// TODO: update c's lxc.snapshot = count
> -- 
> 1.8.1.4
> 

-- 
Stéphane Graber
Ubuntu developer
http://www.ubuntu.com
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