lxc-create: Make location of container rootfs configurable

doc/lxc-create.sgml.in

@@ -123,9 +123,13 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 	</term>
 	<listitem>
 	  <para>
-	    'backingstore' is one of 'none', 'lvm', or 'btrfs'.  The
+	    'backingstore' is one of 'none', 'dir', 'lvm', or 'btrfs'.  The
 	    default is 'none', meaning that the container root filesystem
 	    will be a directory under <filename>@LXCPATH@/container/rootfs</filename>.
+	    'dir' has the same meaning as 'none', but also allows the optional
+	    <replaceable>--dir ROOTFS</replaceable> to be specified, meaning
+	    that the container rootfs should be placed under the specified path,
+	    rather than the default.
 	    The option 'btrfs' need not be specified as it will be used
 	    automatically if the <filename>@LXCPATH@</filename> filesystem is found to
 	    be btrfs.  If backingstore is 'lvm', then an lvm block device will be

src/lxc/lxc-create.in

@@ -26,6 +26,7 @@ usage() {
     echo >&2
     echo "where FS_OPTIONS is one of:" >&2
     echo "  -B none" >&2
+    echo "  -B dir [--dir rootfs_dir]" >&2
     echo "  -B lvm [--lvname LV_NAME] [--vgname VG_NAME] [--fstype FS_TYPE]" >&2
     echo "    [--fssize FS_SIZE]" >&2
     echo "  -B btrfs" >&2
@@ -43,6 +44,7 @@ help() {
     echo "  -B BACKING_STORE   alter the container backing store (default: none)" >&2
     echo "  --lvname LV_NAME   specify the LVM logical volume name" >&2
     echo "                      (default: container name)" >&2
+    echo "  --dir ROOTFS_DIR   specify path for custom rootfs directory location" >&2
     echo "  --vgname VG_NAME   specify the LVM volume group name (default: lxc)" >&2
     echo "  --fstype FS_TYPE   specify the filesystem type (default: ext4)" >&2
     echo "  --fssize FS_SIZE   specify the filesystem size (default: 500M)" >&2
@@ -61,7 +63,7 @@ help() {
 }
 
 shortoptions='hn:f:t:B:'
-longoptions='help,name:,config:,template:,backingstore:,fstype:,lvname:,vgname:,fssize:'
+longoptions='help,name:,config:,template:,backingstore:,fstype:,dir:,lvname:,vgname:,fssize:'
 lxc_path=@LXCPATH@
 bindir=@BINDIR@
 templatedir=@LXCTEMPLATEDIR@
@@ -69,6 +71,7 @@ backingstore=_unset
 fstype=ext4
 fssize=500M
 vgname=lxc
+custom_rootfs=""
 
 getopt=$(getopt -o $shortoptions --longoptions  $longoptions -- "$@")
 if [ $? != 0 ]; then
@@ -104,6 +107,11 @@ while true; do
 		backingstore=$1
 		shift
 		;;
+	    --dir)
+		shift
+		custom_rootfs=$1
+		shift
+		;;
 	    --lvname)
 		shift
 		lvname=$1
@@ -171,9 +179,13 @@ if [ "$(id -u)" != "0" ]; then
    exit 1
 fi
 
+if [ -n "$custom_rootfs" -a "$backingstore" != "dir" ]; then
+   echo "--dir is only valid with -B dir"
+fi
+
 case "$backingstore" in
-    lvm|none|btrfs|_unset) :;;
-    *) echo "$(basename $0): '$backingstore' is not known (try 'none', 'lvm', 'btrfs')" >&2
+    dir|lvm|none|btrfs|_unset) :;;
+    *) echo "$(basename $0): '$backingstore' is not known (try 'none', 'dir', 'lvm', 'btrfs')" >&2
         usage
         exit 1
         ;;
@@ -258,6 +270,14 @@ else
     cp $lxc_config $lxc_path/$lxc_name/config
 fi
 
+if [ -n "$custom_rootfs" ]; then
+	if grep -q "lxc.rootfs" $lxc_path/$lxc_name/config ; then
+		echo "configuration file already specifies a lxc.rootfs"
+		exit 1
+	fi
+	echo "lxc.rootfs = $custom_rootfs" >> $lxc_path/$lxc_name/config
+fi
+
 # Create the fs as needed
 if [ $backingstore = "lvm" ]; then
     [ -d "$rootfs" ] || mkdir $rootfs

src/lxc/lxc-destroy.in

@@ -110,7 +110,7 @@ fi
 # else, ignore it. We'll support deletion of others later.
 rootdev=`grep lxc.rootfs $lxc_path/$lxc_name/config 2>/dev/null | sed -e 's/^[^/]*/\//'`
 if [ -n "$rootdev" ]; then
-	if [ -b "$rootdev" ]; then
+	if [ -b "$rootdev" -o -h "$rootdev" ]; then
 		lvdisplay $rootdev > /dev/null 2>&1
 		if [ $? -eq 0 ]; then
 			echo "removing backing store: $rootdev"
@@ -126,5 +126,6 @@ if [ -n "$rootdev" ]; then
 		fi
 	fi
 fi
+
 # recursively remove the container to remove old container configuration
 rm -rf --one-file-system --preserve-root $lxc_path/$lxc_name

templates/lxc-altlinux.in

@@ -239,11 +239,11 @@ copy_configuration()
 {
 
     mkdir -p $config_path
+    grep -q "^lxc.rootfs" $config_path/config 2>/dev/null || echo "lxc.rootfs = $rootfs_path" >> $config_path/config
     cat <<EOF >> $config_path/config
 lxc.utsname = $name
 lxc.tty = 4
 lxc.pts = 1024
-lxc.rootfs = $rootfs_path
 lxc.mount  = $config_path/fstab
 
 # When using LXC with apparmor, uncomment the next line to run unconfined:
@@ -433,6 +433,11 @@ if [ -f $config_path/config ]; then
     exit 1
 fi
 
+# check for 'lxc.rootfs' passed in through default config by lxc-create
+if grep -q '^lxc.rootfs' $path/config 2>/dev/null ; then
+    rootfs_path=`grep 'lxc.rootfs =' $path/config | awk -F= '{ print $2 }'`
+fi
+
 install_altlinux
 if [ $? -ne 0 ]; then
     echo "failed to install altlinux"

templates/lxc-archlinux.in

@@ -218,11 +218,11 @@ EOF
 # write container configuration files
 function copy_configuration {
     mkdir -p "${config_path}"
+    grep -q "^lxc.rootfs" "${config_path}/config" 2>/dev/null || echo "lxc.rootfs=${rootfs_path}" >> "${config_path}/config"
     cat > "${config_path}/config" << EOF
 lxc.utsname=${name}
 lxc.tty=4
 lxc.pts=1024
-lxc.rootfs=${rootfs_path}
 lxc.mount=${config_path}/fstab
 
 # When using LXC with apparmor, uncomment the next line to run unconfined:
@@ -423,6 +423,10 @@ if [ "${EUID}" != "0" ]; then
 fi
 
 rootfs_path="${path}/rootfs"
+# check for 'lxc.rootfs' passed in through default config by lxc-create
+if grep -q '^lxc.rootfs' $path/config 2>/dev/null ; then
+    rootfs_path=`grep 'lxc.rootfs =' $path/config | awk -F= '{ print $2 }'`
+fi
 config_path="${default_path}/${name}"
 
 revert()

templates/lxc-busybox.in

@@ -228,11 +228,19 @@ copy_configuration()
     rootfs=$2
     name=$3
 
+grep -q "^lxc.rootfs" $path/config 2>/dev/null || echo "lxc.rootfs = $rootfs" >> $path/config
 cat <<EOF >> $path/config
 lxc.utsname = $name
 lxc.tty = 1
 lxc.pts = 1
-lxc.rootfs = $rootfs
+EOF
+
+if [ -d "$rootfs/lib" ]; then
+cat <<EOF >> $path/config
+lxc.mount.entry=/lib $rootfs/lib none ro,bind 0 0
+lxc.mount.entry=/usr/lib $rootfs/usr/lib none ro,bind 0 0
+EOF
+fi
 
 # When using LXC with apparmor, uncomment the next line to run unconfined:
 #lxc.aa_profile = unconfined
@@ -287,7 +295,13 @@ if [ -z "$path" ]; then
     exit 1
 fi
 
-rootfs=$path/rootfs
+# detect rootfs
+config="$path/config"
+if grep -q '^lxc.rootfs' $config 2>/dev/null ; then
+    rootfs=`grep 'lxc.rootfs =' $config | awk -F= '{ print $2 }'`
+else
+    rootfs=$path/rootfs
+fi
 
 install_busybox $rootfs $name
 if [ $? -ne 0 ]; then

templates/lxc-debian.in

@@ -202,10 +202,10 @@ copy_configuration()
     rootfs=$2
     hostname=$3
 
+    grep -q "^lxc.rootfs" $path/config 2>/dev/null || echo "lxc.rootfs = $rootfs" >> $path/config
     cat <<EOF >> $path/config
 lxc.tty = 4
 lxc.pts = 1024
-lxc.rootfs = $rootfs
 lxc.utsname = $hostname
 
 # When using LXC with apparmor, uncomment the next line to run unconfined:
@@ -312,7 +312,14 @@ if [ "$(id -u)" != "0" ]; then
     exit 1
 fi
 
-rootfs=$path/rootfs
+# detect rootfs
+config="$path/config"
+if grep -q '^lxc.rootfs' $config 2>/dev/null ; then
+    rootfs=`grep 'lxc.rootfs =' $config | awk -F= '{ print $2 }'`
+else
+    rootfs=$path/rootfs
+fi
+
 
 install_debian $rootfs
 if [ $? -ne 0 ]; then

templates/lxc-fedora.in

@@ -243,11 +243,11 @@ copy_configuration()
 {
 
     mkdir -p $config_path
+    grep -q "^lxc.rootfs" $config_path/config 2>/dev/null || echo "lxc.rootfs = $rootfs_path" >> $config_path/config
     cat <<EOF >> $config_path/config
 lxc.utsname = $name
 lxc.tty = 4
 lxc.pts = 1024
-lxc.rootfs = $rootfs_path
 lxc.mount  = $config_path/fstab
 
 # When using LXC with apparmor, uncomment the next line to run unconfined:

templates/lxc-lenny.in

@@ -178,10 +178,10 @@ copy_configuration()
     rootfs=$2
     name=$3
 
+    grep -q "^lxc.rootfs" $path/config 2>/dev/null || echo "lxc.rootfs = $rootfs" >> $path/config
     cat <<EOF >> $path/config
 lxc.tty = 4
 lxc.pts = 1024
-lxc.rootfs = $rootfs
 lxc.cgroup.devices.deny = a
 
 # When using LXC with apparmor, uncomment the next line to run unconfined:
@@ -287,7 +287,13 @@ if [ "$(id -u)" != "0" ]; then
     exit 1
 fi
 
-rootfs=$path/rootfs
+# detect rootfs
+config="$path/config"
+if grep -q '^lxc.rootfs' $config 2>/dev/null ; then
+    rootfs=`grep 'lxc.rootfs =' $config | awk -F= '{ print $2 }'`
+else
+    rootfs=$path/rootfs
+fi
 
 install_debian $rootfs
 if [ $? -ne 0 ]; then

templates/lxc-opensuse.in

@@ -254,12 +254,12 @@ copy_configuration()
     rootfs=$2
     name=$3
 
+    grep -q "^lxc.rootfs" $path/config 2>/dev/null || echo "lxc.rootfs = $rootfs" >> $path/config
     cat <<EOF >> $path/config
 lxc.utsname = $name
 
 lxc.tty = 4
 lxc.pts = 1024
-lxc.rootfs = $rootfs
 lxc.mount  = $path/fstab
 
 # When using LXC with apparmor, uncomment the next line to run unconfined:
@@ -367,7 +367,13 @@ if [ "$(id -u)" != "0" ]; then
     exit 1
 fi
 
-rootfs=$path/rootfs
+# detect rootfs
+config="$path/config"
+if grep -q '^lxc.rootfs' $config 2>/dev/null ; then
+    rootfs=`grep 'lxc.rootfs =' $config | awk -F= '{ print $2 }'`
+else
+    rootfs=$path/rootfs
+fi
 
 install_opensuse $rootfs
 if [ $? -ne 0 ]; then

templates/lxc-sshd.in

@@ -108,10 +108,10 @@ copy_configuration()
     rootfs=$2
     name=$3
 
+    grep -q "^lxc.rootfs" $path/config 2>/dev/null || echo "lxc.rootfs = $rootfs" >> $path/config
 cat <<EOF >> $path/config
 lxc.utsname = $name
 lxc.pts = 1024
-lxc.rootfs = $rootfs
 
 # When using LXC with apparmor, uncomment the next line to run unconfined:
 #lxc.aa_profile = unconfined
@@ -207,7 +207,13 @@ if [ -z "$path" ]; then
     exit 1
 fi
 
-rootfs=$path/rootfs
+# detect rootfs
+config="$path/config"
+if grep -q '^lxc.rootfs' $config 2>/dev/null ; then
+    rootfs=`grep 'lxc.rootfs =' $config | awk -F= '{ print $2 }'`
+else
+    rootfs=$path/rootfs
+fi
 
 install_sshd $rootfs
 if [ $? -ne 0 ]; then

templates/lxc-ubuntu-cloud.in

@@ -46,12 +46,12 @@ lxc.network.hwaddr = 00:16:3e:$(openssl rand -hex 3| sed 's/\(..\)/\1:/g; s/.$//
 EOF
     fi
 
+    grep -q "^lxc.rootfs" $path/config 2>/dev/null || echo "lxc.rootfs = $rootfs" >> $path/config
     cat <<EOF >> $path/config
 lxc.utsname = $name
 
 lxc.tty = 4
 lxc.pts = 1024
-lxc.rootfs = $rootfs
 lxc.mount  = $path/fstab
 lxc.arch = $arch
 lxc.cap.drop = sys_module mac_admin
@@ -249,7 +249,13 @@ if [ "$(id -u)" != "0" ]; then
     exit 1
 fi
 
-rootfs=$path/rootfs
+# detect rootfs
+config="$path/config"
+if grep -q '^lxc.rootfs' $config 2>/dev/null ; then
+    rootfs=`grep 'lxc.rootfs =' $config | awk -F= '{ print $2 }'`
+else
+    rootfs=$path/rootfs
+fi
 
 type ubuntu-cloudimg-query
 type wget

templates/lxc-ubuntu.in

@@ -303,13 +303,13 @@ lxc.network.hwaddr = 00:16:3e:$(openssl rand -hex 3| sed 's/\(..\)/\1:/g; s/.$//
 EOF
     fi
 
+    grep -q "^lxc.rootfs" $path/config 2>/dev/null || echo "lxc.rootfs = $rootfs" >> $path/config
     cat <<EOF >> $path/config
 lxc.utsname = $name
 
 lxc.devttydir =$ttydir
 lxc.tty = 4
 lxc.pts = 1024
-lxc.rootfs = $rootfs
 lxc.mount  = $path/fstab
 lxc.arch = $arch
 lxc.cap.drop = sys_module mac_admin mac_override
@@ -670,7 +670,13 @@ if [ "$(id -u)" != "0" ]; then
     exit 1
 fi
 
-rootfs=$path/rootfs
+# detect rootfs
+config="$path/config"
+if grep -q '^lxc.rootfs' $config 2>/dev/null ; then
+    rootfs=`grep 'lxc.rootfs =' $config | awk -F= '{ print $2 }'`
+else
+    rootfs=$path/rootfs
+fi
 
 install_ubuntu $rootfs $release $flushcache
 if [ $? -ne 0 ]; then