Allow custom rootfs labels

Per [1], our current root label of cloudimg-root does not work with
XFS because XFS only allows 12 character labels.  This change
addresses that by allowing a custom rootfs label to be specified
in the call to disk-image-create.  There should be no backwards
compatibility concerns as the default label is unchanged.  Any
external elements dealing with the label would need to be updated
to support this new feature, but should continue to work as before
as long as a custom label is not specified.

[1]: https://bugzilla.redhat.com/show_bug.cgi?id=1139584

Change-Id: I596104d1a63b5dc6549e8460a1ae3da00165ef04

bin/disk-image-create

@@ -62,6 +62,7 @@ function show_options () {
     echo "    --offline -- do not update cached resources"
     echo "    --qemu-img-options -- option flags to be passed directly to qemu-img."
     echo "       Options need to be comma separated, and follow the key=value pattern."
+    echo "    --root-label label -- label for the root filesystem.  Defaults to 'cloudimg-rootfs'."
     if [ "$IS_RAMDISK" == "0" ]; then
         echo "    -n skip the default inclusion of the 'base' element"
         echo "    -p package[,package,package] -- list of packages to install in the image"
@@ -85,7 +86,8 @@ function show_options () {
 
 INSTALL_PACKAGES=""
 COMPRESS_IMAGE="true"
-TEMP=`getopt -o a:ho:t:xucnp: -l no-tmpfs,offline,help,min-tmpfs:,image-size:,image-cache:,max-online-resize:,qemu-img-options: -n $SCRIPTNAME -- "$@"`
+DIB_ROOT_LABEL=""
+TEMP=`getopt -o a:ho:t:xucnp: -l no-tmpfs,offline,help,min-tmpfs:,image-size:,image-cache:,max-online-resize:,qemu-img-options:,root-label: -n $SCRIPTNAME -- "$@"`
 if [ $? -ne 0 ] ; then echo "Terminating..." >&2 ; exit 1 ; fi
 
 # Note the quotes around `$TEMP': they are essential!
@@ -109,6 +111,7 @@ while true ; do
         --no-tmpfs) shift; export DIB_NO_TMPFS=1;;
         --offline) shift; export DIB_OFFLINE=1;;
         --qemu-img-options) QEMU_IMG_OPTIONS=$2; shift 2;;
+        --root-label) export DIB_ROOT_LABEL=$2; shift 2;;
         --) shift ; break ;;
         *) echo "Internal error!" ; exit 1 ;;
     esac
@@ -135,9 +138,21 @@ fi
 arg_to_elements "$@"
 
 export IMAGE_NAME=${IMAGE_NAME%%\.${IMAGE_TYPE}}
+# FS_TYPE isn't available until after we source img-defaults
+if [ -z "$DIB_ROOT_LABEL" ]; then
+    # NOTE(bnemec): XFS has a limit of 12 characters for filesystem labels
+    # Not changing the default for other filesystems to maintain backwards compatibility
+    if [ "$FS_TYPE" = "xfs" ]; then
+        DIB_ROOT_LABEL="img-rootfs"
+    else
+        DIB_ROOT_LABEL="cloudimg-rootfs"
+    fi
+fi
 
 mk_build_dir
 create_base
+# This variable needs to be propagated into the chroot
+echo "export DIB_ROOT_LABEL=\"${DIB_ROOT_LABEL}\"" > $TMP_HOOKS_PATH/environment.d/10-dib-root-label.bash
 run_d extra-data
 # Run pre-install scripts. These do things that prepare the chroot for package installs
 run_d_in_target pre-install
@@ -184,7 +199,7 @@ LOOPDEV=$(sudo losetup --show -f $TMP_IMAGE_PATH)
 export EXTRA_UNMOUNT="detach_loopback $LOOPDEV"
 export IMAGE_BLOCK_DEVICE=$LOOPDEV
 eval_run_d block-device "IMAGE_BLOCK_DEVICE="
-sudo mkfs $MKFS_OPTS -t $FS_TYPE -L cloudimg-rootfs ${IMAGE_BLOCK_DEVICE}
+sudo mkfs $MKFS_OPTS -t $FS_TYPE -L ${DIB_ROOT_LABEL} ${IMAGE_BLOCK_DEVICE}
 mkdir $TMP_BUILD_DIR/mnt
 sudo mount ${IMAGE_BLOCK_DEVICE} $TMP_BUILD_DIR/mnt
 sudo mv -t $TMP_BUILD_DIR/mnt ${TMP_BUILD_DIR}/built/*

elements/debian/root.d/08-debootstrap

@@ -80,9 +80,9 @@ EOF
     sudo install -d -m 0755 -o root -g root ${TARGET_ROOT}/etc/sudoers.d
     sudo sh -c "echo 'debian ALL=(ALL) NOPASSWD:ALL' > ${TARGET_ROOT}/etc/sudoers.d/debian-cloud-init"
     sudo chmod 0440 ${TARGET_ROOT}/etc/sudoers.d/debian-cloud-init
-    sudo sh -c "echo 'proc /proc proc nodev,noexec,nosuid 0 0
+    sudo sh -c "echo \"proc /proc proc nodev,noexec,nosuid 0 0
-LABEL=cloudimg-rootfs / ext4 errors=remount-ro 0 1
+LABEL=${DIB_ROOT_LABEL} / ext4 errors=remount-ro 0 1
-' > ${TARGET_ROOT}/etc/fstab"
+\" > ${TARGET_ROOT}/etc/fstab"
     sudo sh -c "echo 'blacklist pcspkr' > ${TARGET_ROOT}/etc/modprobe.d/blacklist.conf"
     sudo sh -c "echo 'debian' > ${TARGET_ROOT}/etc/hostname"
 

elements/rpm-distro/post-install.d/05-fstab-rootfs-label

@@ -6,4 +6,4 @@ set -o pipefail
 # Fedora 18 sets up for root to have a label of "_/"
 # Fedora 19 sets up for root to have a UUID
 # This regex will catch both
-sed -i "s%.*\s\/\s%LABEL=cloudimg-rootfs / %" /etc/fstab
+sed -i "s%.*\s\/\s%LABEL=${DIB_ROOT_LABEL} / %" /etc/fstab

elements/vm/cleanup.d/51-bootloader

@@ -38,6 +38,6 @@ DEFAULT linux
 
 LABEL linux
     KERNEL /boot/$KERNEL
-    APPEND ro root=LABEL=cloudimg-rootfs console=tty0 console=ttyS0,115200 nofb nomodeset vga=normal
+    APPEND ro root=LABEL=${DIB_ROOT_LABEL} console=tty0 console=ttyS0,115200 nofb nomodeset vga=normal
     INITRD /boot/$RAMDISK
 _EOF_"

elements/vm/finalise.d/51-bootloader

@@ -166,12 +166,12 @@ function install_grub2 {
     # force use of a LABEL:
     # NOTE: Updating the grub config by hand once deployed should work, its just
     # prepping it in a different environment that needs fiddling.
-    sed -i "s%$PART_DEV%LABEL=cloudimg-rootfs%" $GRUB_CFG
+    sed -i "s%$PART_DEV%LABEL=${DIB_ROOT_LABEL}%" $GRUB_CFG
-    sed -i "s%search --no-floppy --fs-uuid --set=root .*$%search --no-floppy --set=root --label cloudimg-rootfs%" $GRUB_CFG
+    sed -i "s%search --no-floppy --fs-uuid --set=root .*$%search --no-floppy --set=root --label ${DIB_ROOT_LABEL}%" $GRUB_CFG
-    sed -i "s%root=UUID=[A-Za-z0-9\-]*%root=LABEL=cloudimg-rootfs%" $GRUB_CFG
+    sed -i "s%root=UUID=[A-Za-z0-9\-]*%root=LABEL=${DIB_ROOT_LABEL}%" $GRUB_CFG
     if [ "$DIST" = 'Fedora' ] ; then
         if [ $(lsb_release -rs) = '19' ]; then
-            sed -i "s%UUID=[A-Za-z0-9\-]*%LABEL=cloudimg-rootfs%" /etc/fstab
+            sed -i "s%UUID=[A-Za-z0-9\-]*%LABEL=${DIB_ROOT_LABEL}%" /etc/fstab
         fi
         # Fix efi specific instructions in grub config file
         if [ -d /sys/firmware/efi ]; then