Add example hooks from Ubuntu package

Makefile.am

@@ -2,8 +2,8 @@
 
 ACLOCAL_AMFLAGS = -I config
 
-SUBDIRS = config src templates doc
-DIST_SUBDIRS = config src templates doc
+SUBDIRS = config src templates doc hooks
+DIST_SUBDIRS = config src templates doc hooks
 EXTRA_DIST = autogen.sh lxc.spec CONTRIBUTING MAINTAINERS ChangeLog
 RPMARGS =
 

configure.ac

@@ -219,6 +219,7 @@ AS_AC_EXPAND(LXCPATH, "$with_config_path")
 AS_AC_EXPAND(LXC_GLOBAL_CONF, "$with_global_conf")
 AS_AC_EXPAND(LXCROOTFSMOUNT, "$with_rootfs_path")
 AS_AC_EXPAND(LXCTEMPLATEDIR, "$datadir/lxc/templates")
+AS_AC_EXPAND(LXCHOOKDIR, "$datadir/lxc/hooks")
 AS_AC_EXPAND(LXCINITDIR, "$libexecdir")
 AS_AC_EXPAND(LOGPATH, "$with_log_path")
 
@@ -350,6 +351,8 @@ AC_CONFIG_FILES([
 	doc/examples/lxc-veth.conf
 	doc/examples/lxc-complex.conf
 
+	hooks/Makefile
+
 	templates/Makefile
 	templates/lxc-lenny
 	templates/lxc-debian

hooks/Makefile.am

+hooksdir=@LXCHOOKDIR@
+
+hooks_SCRIPTS = \
+	mountcgroups \
+	mountecryptfsroot

hooks/mountcgroups

+#!/bin/bash
+
+# (C) Copyright Canonical 2011,2012
+
+# 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
+
+#
+# This is an example hook to mount all mounted cgroups in the
+# container.  Only the container's own cgroup (not parents) will be
+# accessible to the container.  You can enable this by adding
+# lxc.hook.mount = /usr/share/lxc/hooks/mountcgroups
+# to your container's configuration file.
+
+set -e
+
+c=$1
+d=/sys/fs/cgroup
+d2=$LXC_ROOTFS_MOUNT/${d}
+if [ ! -d "$d" ]; then
+    exit 0
+fi
+
+mount -n -t tmpfs tmpfs ${d2}
+
+for dir in `/bin/ls $d`; do
+    mkdir -p "${d}/${dir}/lxc/${c}/${c}.real"
+    echo 1 > "${d}/${dir}/lxc/${c}/${c}.real/tasks"
+    mkdir -p ${d2}/${dir}
+    mount -n --bind "${d}/${dir}/lxc/${c}/${c}.real" "${d2}/${dir}"
+done

hooks/mountecryptfsroot

+#!/bin/sh
+
+# (C) Copyright Canonical 2011-2013
+
+# 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
+
+# This hook can be used to mount an ecryptfs filesystem as a container's
+# rootfs.
+# To use this hook, assuming your container is called q1,
+#  1. add 'lxc.hook.pre-mount = /usr/share/lxc/hooks/mountecryptfsroot' to
+#     the container's configuration file
+#  2. Create /var/lib/lxc/q1/ecryptfs-root
+#     a. mkdir /var/lib/lxc/q1/ecryptfs-root
+#  3. convert your container's root filesystem to be ecryptfs-backed.  Assuming
+#     your container is called 'q1', do
+#     a. c=q1
+#     b. mv /var/lib/lxc/$c/rootfs /var/lib/lxc/$c/rootfs.plain
+#     c. mkdir /var/lib/lxc/$c/rootfs{,.crypt}
+#     d. sig=`echo none | ecryptfs-add-passphrase | grep -v Passphrase | cut -d[ -f 2 | cut -d] -f 1`
+#     e. echo $sig > /var/lib/lxc/$c/sig
+#     f. mount -t ecryptfs -o ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_passthrough=n,ecryptfs_enable_filename_crypto=n,ecryptfs_sig=${sig},sig=${sig},verbosity=0 /var/lib/lxc/$c/rootfs.crypt /var/lib/lxc/$c/rootfs
+#     g. rsync -va /var/lib/lxc/$c/rootfs.plain/ /var/lib/lxc/$c/rootfs/
+#     h. umount /var/lib/lxc/$c/rootfs
+#     i. rm -rf /var/lib/lxc/$c/rootfs.plain
+#  4. Now you can start your container by adding the passphrase to your
+#     in-kernel keyring using 'ecryptfs-add-passphrase', then starting your
+#     container as normal.
+#     a. echo none | ecryptfs-add-passphrase
+#     b. lxc-start -n q1
+#  Note that you may well want to use a wrapped passhrase (see the ecryptfs-wrap-passphrase(1) manual page).
+
+set -e
+ecryptfs_crypt=$(echo $LXC_ROOTFS_PATH | sed 's/rootfs$/rootfs.crypt/')
+sigfile=$(echo $LXC_CONFIG_FILE | sed 's/config$/sig/')
+
+sig=`cat $sigfile`
+mount -n -t ecryptfs -o ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_passthrough=n,ecryptfs_enable_filename_crypto=n,ecryptfs_sig=${sig},sig=${sig},verbosity=0 $ecryptfs_crypt $LXC_ROOTFS_PATH
+exit 0