Patch to update Ubuntu template in lxc-templates-1.0.7-1.el7.x86_64 to latest version (as of 2015-07-28)

lxc-ubuntu.patch

--- lxc-ubuntu	2014-12-07 13:23:40.000000000 -0500
+++ lxc-ubuntu-new	2015-07-28 15:49:46.633633812 -0400
@@ -46,6 +46,41 @@
     . /etc/default/lxc
 fi
 
+# Check if given path is in a btrfs partition
+is_btrfs()
+{
+    [ -e $1 -a $(stat -f -c '%T' $1) = "btrfs" ]
+}
+
+# Check if given path is the root of a btrfs subvolume
+is_btrfs_subvolume()
+{
+    [ -d $1 -a $(stat -f -c '%T' $1) = "btrfs" -a $(stat -c '%i' $1) -eq 256 ]
+}
+
+try_mksubvolume()
+{
+    path=$1
+    [ -d $path ] && return 0
+    mkdir -p $(dirname $path)
+    if which btrfs >/dev/null 2>&1 && is_btrfs $(dirname $path); then
+        btrfs subvolume create $path
+    else
+        mkdir -p $path
+    fi
+}
+
+try_rmsubvolume()
+{
+    path=$1
+    [ -d $path ] || return 0
+    if which btrfs >/dev/null 2>&1 && is_btrfs_subvolume $path; then
+        btrfs subvolume delete $path
+    else
+        rm -rf $path
+    fi
+}
+
 configure_ubuntu()
 {
     rootfs=$1
@@ -278,8 +313,8 @@
 
 cleanup()
 {
-    rm -rf $cache/partial-$arch
-    rm -rf $cache/rootfs-$arch
+    try_rmsubvolume $cache/partial-$arch
+    try_rmsubvolume $cache/rootfs-$arch
 }
 
 suggest_flush()
@@ -311,7 +346,7 @@
 
     trap cleanup EXIT SIGHUP SIGINT SIGTERM
     # check the mini ubuntu was not already downloaded
-    mkdir -p "$cache/partial-$arch"
+    try_mksubvolume "$cache/partial-$arch"
     if [ $? -ne 0 ]; then
         echo "Failed to create '$cache/partial-$arch' directory"
         return 1
@@ -370,8 +405,16 @@
 
     # make a local copy of the miniubuntu
     echo "Copying rootfs to $rootfs ..."
-    mkdir -p $rootfs
-    rsync -Ha $cache/rootfs-$arch/ $rootfs/ || return 1
+    try_mksubvolume $rootfs
+    if which btrfs >/dev/null 2>&1 && is_btrfs_subvolume $cache/rootfs-$arch && is_btrfs_subvolume $rootfs; then
+      realrootfs=$(dirname $config)/rootfs
+      [ "$rootfs" = "$realrootfs" ] || umount $rootfs || return 1
+      btrfs subvolume delete $realrootfs || return 1
+      btrfs subvolume snapshot $cache/rootfs-$arch $realrootfs || return 1
+      [ "$rootfs" = "$realrootfs" ] || mount --bind $realrootfs $rootfs || return 1
+    else
+      rsync -Ha $cache/rootfs-$arch/ $rootfs/ || return 1
+    fi
     return 0
 }
 
@@ -393,8 +436,8 @@
 
         if [ $flushcache -eq 1 ]; then
             echo "Flushing cache..."
-            rm -rf "$cache/partial-$arch"
-            rm -rf "$cache/rootfs-$arch"
+            try_rmsubvolume $cache/partial-$arch
+            try_rmsubvolume $cache/rootfs-$arch
         fi
 
         echo "Checking cache download in $cache/rootfs-$arch ... "
@@ -440,9 +483,6 @@
     fi
 
     # Generate the configuration file
-    ## Create the fstab (empty by default)
-    touch $path/fstab
-
     ## Relocate all the network config entries
     sed -i -e "/lxc.network/{w ${path}/config-network" -e "d}" $path/config
 
@@ -465,7 +505,6 @@
     [ -e "$path/config-auto" ] && cat $path/config-auto >> $path/config && rm $path/config-auto
     grep -q "^lxc.rootfs" $path/config 2>/dev/null || echo "lxc.rootfs = $rootfs" >> $path/config
     cat <<EOF >> $path/config
-lxc.mount = $path/fstab
 lxc.utsname = $name
 lxc.arch = $arch
 EOF
@@ -497,28 +536,6 @@
 EOF
     chmod +x $rootfs/usr/sbin/policy-rc.d
 
-    if [ ! -f $rootfs/etc/init/container-detect.conf ]; then
-        # Make sure we have a working resolv.conf
-        cresolvonf="${rootfs}/etc/resolv.conf"
-        mv $cresolvonf ${cresolvonf}.lxcbak
-        cat /etc/resolv.conf > ${cresolvonf}
-
-        # for lucid, if not trimming, then add the ubuntu-virt
-        # ppa and install lxcguest
-        if [ $release = "lucid" ]; then
-            chroot $rootfs apt-get update
-            install_packages $rootfs "python-software-properties"
-            chroot $rootfs add-apt-repository ppa:ubuntu-virt/ppa
-        fi
-
-        chroot $rootfs apt-get update
-        chroot $rootfs apt-get install --force-yes -y lxcguest
-
-        # Restore old resolv.conf
-        rm -f ${cresolvonf}
-        mv ${cresolvonf}.lxcbak ${cresolvonf}
-    fi
-
     # If the container isn't running a native architecture, setup multiarch
     if [ -x "$(ls -1 ${rootfs}/usr/bin/qemu-*-static 2>/dev/null)" ]; then
         dpkg_version=$(chroot $rootfs dpkg-query -W -f='${Version}' dpkg)
@@ -616,7 +633,7 @@
     while [ ${h2:0:1} = "/" ]; do
         h2=${h2#/}
     done
-    echo "$h $h2 none bind 0 0" >> $path/fstab
+    echo "lxc.mount.entry = $h $h2 none bind 0 0" >> $path/config
 
     # Make sure the group exists in container
     grp=`echo $pwd | cut -d: -f 4`  # group number for $user