Add scripts tripleo-mount-image, tripleo-unmount-image

Now that the whole-disk image is being deployed, mounting an image
using tools like kpartx or qemu-nbd is much more involved, requiring
knowledge of the image LVM volumes and their intended mount points.

The scripts tripleo-mount-image and tripleo-unmount-image will mount
the contents of an overcloud image file using qemu-nbd, making it available
for chroot, or other read/write image operations. The scripts handle
partition images (overcloud-full.qcow2) as well as the whole-disk image
(overcloud-hardened-uefi-full.qcow2) with its multiple LVM volume mount
points.

qemu-nbd was chosen over kpartx as downstream documentation[1] has
standardized on this tool for mount based image modifications.

tripleo-unmount-image is a symlink to tripleo-mount-image and behaves
differently based on the script name.

Blueprint: whole-disk-default
[1] https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/16.1/html/bare_metal_provisioning/booting-from-cinder-volumes

Change-Id: I3267b4ae5200eeed333a9518865260d23315f52c
This commit is contained in:
Steve Baker 2021-08-26 15:40:09 +12:00
parent 58fff86253
commit 5f55ee2bd1
4 changed files with 212 additions and 0 deletions

View File

@ -0,0 +1,9 @@
---
features:
- |
The scripts `tripleo-mount-image` and `tripleo-unmount-image` will mount
the contents of an overcloud image file using qemu-nbd, making it available
for chroot, or other read/write image operations. The scripts handle
partition image (overcloud-full.qcow2) as well as the whole-disk image
(overcloud-hardened-uefi-full.qcow2) with its multiple LVM volume mount
points.

200
scripts/tripleo-mount-image Executable file
View File

@ -0,0 +1,200 @@
#!/bin/bash
# Copyright 2021 Red Hat, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#
# Script to upload files to a Artifact container for deployment via
# TripleO Heat Templates.
#
set -eu
set -x
set -o pipefail
SCRIPT_NAME=$(basename $0)
NBD_DEVICE=/dev/nbd0
if [ ! -a "${NBD_DEVICE}" ]; then
modprobe nbd
fi
# supported LVM devices and mount points for whole-disk overcloud images
MOUNTS="/dev/mapper/vg-lv_var:/var \
/dev/mapper/vg-lv_log:/var/log \
/dev/mapper/vg-lv_audit:/var/log/audit \
/dev/mapper/vg-lv_home:/home \
/dev/mapper/vg-lv_tmp:/tmp \
/dev/mapper/vg-lv_srv:/srv"
REVERSE_MOUNTS=""
for m in $MOUNTS; do
REVERSE_MOUNTS="$m $REVERSE_MOUNTS"
done
mount_show_options() {
echo "Usage: $SCRIPT_NAME"
echo
echo "Options:"
echo " -h, --help -- print this help."
echo " -a <file> -- Image file to mount."
echo " -m <directory> -- Directory to mount image to."
echo " -n <nbd device> -- NBD device to use."
echo " Defaults to /dev/nbd0"
echo
echo "Mount an overcloud image to a directory"
echo
exit $1
}
unmount_show_options() {
echo "Usage: $SCRIPT_NAME"
echo
echo "Options:"
echo " -h, --help -- print this help."
echo " -m <directory> -- Directory to unmount."
echo " -n <nbd device> -- NBD device to disconnect."
echo " Defaults to /dev/nbd0"
echo
echo "Unmount a mounted overcloud image"
echo
exit $1
}
mount_volume () {
if [ -b "$1" ]; then
if [ ! -d $2 ]; then
mkdir $2
fi
mount $1 $2
fi
}
unmount_volume () {
if mountpoint "$1"; then
umount $1
fi
}
remove_device () {
if [ -b "/dev/mapper/$1" ]; then
dmsetup remove $1
fi
}
mount_image() {
set -x
qemu-nbd --connect $NBD_DEVICE $IMAGE_FILE
# search for the vg volume group, this is automatic in some environments
vgscan
# refresh for when this script is called with different values of $NBD_DEVICE
vgchange --refresh
# activate new logical volumes, this is automatic in some environments
vgchange -ay
if [ -b "${NBD_DEVICE}p3" ]; then
# 3 partitions in the image, so assume the first 2 are boot partitions
if [ -b "/dev/mapper/vg-lv_root" ]; then
# a whole-disk overcloud with lvm volumes
# for example, overcloud-hardened-uefi-full.qcow2
mount /dev/mapper/vg-lv_root $MOUNT_DIR
for m in $MOUNTS; do
device=${m%:*}
path=${m#*:}
mount_volume $device $MOUNT_DIR$path
done
else
# a whole-disk overcloud with a single root partition
# for example, overcloud-hardened-full.qcow2
mount ${NBD_DEVICE}p3 $MOUNT_DIR
fi
# the EFI partition may be the first or second, try both
if blkid -t PARTLABEL="ESP" ${NBD_DEVICE}p1 ; then
mount ${NBD_DEVICE}p1 $MOUNT_DIR/boot/efi
elif blkid -t PARTLABEL="ESP" ${NBD_DEVICE}p2 ; then
mount ${NBD_DEVICE}p2 $MOUNT_DIR/boot/efi
fi
else
# a partition image
# for example, overcloud-full.qcow2
if [ -b "${NBD_DEVICE}p1" ]; then
mount ${NBD_DEVICE}p1 $MOUNT_DIR
else
mount ${NBD_DEVICE} $MOUNT_DIR
fi
fi
}
unmount_image() {
set -x
if mountpoint "$MOUNT_DIR"; then
for m in $REVERSE_MOUNTS; do
path=${m#*:}
unmount_volume $MOUNT_DIR$path
done
unmount_volume $MOUNT_DIR/boot/efi
unmount_volume $MOUNT_DIR
fi
qemu-nbd --disconnect $NBD_DEVICE
vgchange --refresh vg || true
for m in $REVERSE_MOUNTS; do
device=${m%:*}
remove_device $device
done
remove_device vg-lv_root
}
if [ $SCRIPT_NAME == "tripleo-unmount-image" ]; then
TEMP=`getopt -o hm:n: -n $SCRIPT_NAME -- "$@"`
if [ $? != 0 ]; then
echo "Terminating..." >&2
exit 1
fi
eval set -- "$TEMP"
while true ; do
case "$1" in
-h|--help) unmount_show_options 0 >&2;;
-m) MOUNT_DIR=$2 ; shift 2;;
-n) NBD_DEVICE=$2 ; shift 2;;
--) shift ; break;;
*) echo "Error: unsupported option $1." ; exit 1;;
esac
done
unmount_image
else
TEMP=`getopt -o ha:m:n: -n $SCRIPT_NAME -- "$@"`
if [ $? != 0 ]; then
echo "Terminating..." >&2
exit 1
fi
eval set -- "$TEMP"
while true ; do
case "$1" in
-h|--help) mount_show_options 0 >&2;;
-a) IMAGE_FILE=$2 ; shift 2;;
-m) MOUNT_DIR=$2 ; shift 2;;
-n) NBD_DEVICE=$2 ; shift 2;;
--) shift ; break;;
*) echo "Error: unsupported option $1." ; exit 1;;
esac
done
mount_image
fi

View File

@ -0,0 +1 @@
tripleo-mount-image

View File

@ -32,6 +32,8 @@ scripts =
scripts/pull-puppet-modules scripts/pull-puppet-modules
scripts/tripleo-build-images scripts/tripleo-build-images
scripts/tripleo-config-download scripts/tripleo-config-download
scripts/tripleo-mount-image
scripts/tripleo-unmount-image
scripts/upload-puppet-modules scripts/upload-puppet-modules
scripts/upload-swift-artifacts scripts/upload-swift-artifacts