diskimage-builder/lib/common-functions
Devananda van der Veen d935fc0e07 be smarter about mounting qcow images
some images have partition tables, some don't
2012-11-21 19:00:53 -08:00

113 lines
3.2 KiB
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# Copyright 2012 Hewlett-Packard Development Company, L.P.
# All Rights Reserved.
#
# 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.
function mk_build_dir () {
export TMP_BUILD_DIR=$(mktemp -t -d image.XXXXXXXX)
[ $? -eq 0 ] || die "Failed to create tmp directory"
trap cleanup EXIT
echo Building in $TMP_BUILD_DIR
export TMP_IMAGE_PATH=$TMP_BUILD_DIR/image
export TMP_HOOKS_PATH=$TMP_BUILD_DIR/hooks
}
function save_image () {
# TODO: this really should rename the old file
if [ -f $1 ] ; then
echo "Old Image file Found REMOVING"
rm -f $1
fi
cp $TMP_IMAGE_PATH $1
rm -r $TMP_BUILD_DIR
# All done!
trap EXIT
echo "Image file $1 created..."
}
function generate_hooks () {
mkdir -p $TMP_HOOKS_PATH
for _FLAVOUR in $IMAGE_FLAVOUR ; do
[ -d $FLAVOURS_DIR/$_FLAVOUR ] || die "The flavour does not exist." ;
cp -t $TMP_HOOKS_PATH -a $FLAVOURS_DIR/$_FLAVOUR/* ;
done
}
# Check that a real flavour has been chosen (prevents foot-guns)
function check_flavour () {
[ -d $TMP_HOOKS_PATH ] || generate_hooks
}
# Run a hook, looking for a regex in its stdout, and eval the matched lines.
# $1 is the hook to run
# $2 is the regex to look for
function eval_run_d () {
local TEMP=`run_d $1`
echo "$TEMP"
if [ `echo "$TEMP" | grep -s "$2"` ]; then
TEMP=`echo "$TEMP" | grep "$2"`
eval "$TEMP"
fi
}
# Usage: map_nbd $image
# Returns nbd device path
function map_nbd {
(lsmod | grep '^nbd ') || sudo modprobe nbd max_part=16
if [[ $(qemu-nbd --help | grep cache) == *writeback* ]] ; then
CACHE="--cache=writeback"
else
echo "Warning: qemu-nbd without --cache=writeback is /slow/."
CACHE=""
fi
NBD_DEV=
for i in `seq 0 15`; do
if [ ! -e /sys/block/nbd$i/pid ]; then
NBD_DEV=/dev/nbd$i
# Connect to nbd and wait till it is ready
sudo qemu-nbd -c $NBD_DEV $CACHE $1
if ! timeout 60 sh -c "while ! [ -e /sys/block/nbd$i/pid ]; do sleep 1; done"; then
echo "Couldn't connect $NBD_DEV"
exit 1
fi
break
fi
done
if [ -z "$NBD_DEV" ]; then
echo "No free NBD slots"
exit 1
fi
}
# Delete and unmount the working dir used in extracting kernel/initrd
function unmount_qcow_image () {
sudo umount $WORK_DIR || true
sudo qemu-nbd -d $NBD_DEV || true
sudo rm -rf $WORK_DIR
trap - SIGHUP SIGINT SIGTERM EXIT
}
function mount_qcow_image() {
trap unmount_qcow_image SIGHUP SIGINT SIGTERM EXIT
WORK_DIR=$(mktemp -d)
map_nbd $1
if [ -e "${NBD_DEV}p1" ]; then
sudo mount ${NBD_DEV}p1 $WORK_DIR
else
sudo mount ${NBD_DEV} $WORK_DIR
fi
}