diff options
Diffstat (limited to 'builder/dnbd3-qcow2-rootfs/scripts/setup-qcow2')
| -rwxr-xr-x | builder/dnbd3-qcow2-rootfs/scripts/setup-qcow2 | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/builder/dnbd3-qcow2-rootfs/scripts/setup-qcow2 b/builder/dnbd3-qcow2-rootfs/scripts/setup-qcow2 new file mode 100755 index 00000000..70babc17 --- /dev/null +++ b/builder/dnbd3-qcow2-rootfs/scripts/setup-qcow2 @@ -0,0 +1,137 @@ +#!/usr/bin/bash + +# dracut-lib to use debugging functions +command -v warn >/dev/null || . /lib/dracut-lib.sh +command -v emergency_shell >/dev/null || . /lib/dracut-lib.sh + +############################################################################### +# GLOBALS +# +# TODO make this configurable +[ -f /opt/openslx/config ] && . /opt/openslx/config +[ -z $SLX_DNBD3_SERVER ] && SLX_DNBD3_SERVER="132.230.4.1" +[ -z $SLX_STAGE4 ] && SLX_STAGE4="stage4/joe/centos7" +[ -z $SLX_STAGE4_RID ] && SLX_STAGE4_RID="4" +declare -rg DNBD3_SERVER="$SLX_DNBD3_SERVER" +declare -rg DNBD3_IMAGE="$SLX_STAGE4" +declare -rg DNBD3_RID="$SLX_STAGE4_RID" +declare -rg DNBD3_DEVICE="/dev/dnbd0" +declare -rg QCOW_CONTAINER="/opt/openslx/system/system.qcow2" +# +# END GLOBALS +############################################################################### + +############################################################################### +# FUNCTION DEFINITIONS +# +# helper to do some sanity checks +check_dnbd3() { + if [ ! command -v "dnbd3-client" >/dev/null ]; then + warn "No 'dnbd3-client' found. Was the initramfs built correctly?" + emergency_shell -n "Error in $0" + return 1 + fi + return 0 +} + +# helper to connect to the dnbd3-server +connect_dnbd3() { + # check if it already connected + local current_image_name="$(cat /sys/block/${DNBD3_DEVICE#/dev/}/net/image_name)" + [ "x${current_image_name}" != "x(null)" ] && return 0 + + # not connected yet, do it + if ! dnbd3-client -h "${DNBD3_SERVER}" \ + -i "${DNBD3_IMAGE}" \ + -r "${DNBD3_RID}" \ + -d "${DNBD3_DEVICE}" ; then + warn "Failed to mount $DNBD3_IMAGE from $DNBD3_SERVER to $DNBD3_DEVICE" + emergency_shell -n "Error in $0" + return 1 + fi + return 0 +} + +# helper to create the qcow2 container file using +# DNBD3_DEVICE as the base of the filesystem +# QCOW_CONTAINER as the writable file +# (our future rootfs) +create_qcow() { + # check if we already created the qcow2-container + [ -e "$QCOW_CONTAINER" ] && return 0 + + # check if we have our target directory, if not create it + [ ! -d "$(busybox dirname $QCOW_CONTAINER)" ] && \ + mkdir -p "$(busybox dirname $QCOW_CONTAINER)" + + # we did not, let's create it + if ! qemu-img create -f qcow2 -o \ + backing_file="$DNBD3_DEVICE",backing_fmt=qcow2 "$QCOW_CONTAINER"; then + warn "Failed to create qcow2-Container from $DNBD3_DEVICE" + emergency_shell -n "Error in $0" + rm -f -- "$QCOW_CONTAINER" + return 1 + fi + return 0 +} +# helper to start qemu-nbd on localhost:2000 +# use our wrapper to set argv[0][0] to '@' +# this keeps qemu-nbd running after switching root +export_qcow() { + # check if we already have a qemu-nbd + if [ -e /tmp/qemu-nbd.pid ]; then + kill -0 $(cat /tmp/qemu-nbd.pid) && return 0 + fi + # since we use the wrapper, we need a little more logic to see if it runs + /usr/bin/systemd-preserve-process-marker \ + /usr/bin/qemu-nbd -t -p 2000 "$QCOW_CONTAINER" & + # the wrapper returns 255 if the qemu-nbd binary is missing + local qemu_nbd_pid="$!" + for i in 0.5 1 2; do + sleep $i + if ! kill -0 $qemu_nbd_pid; then + # not running + wait $qemu_nbd_pid + local ret_wrapper="$?" + if [ "${ret_wrapper}" -eq 127 ]; then + # wrapper was not found by bash + warn "No such file or directory: /usr/bin/systemd-preserve-process-marker" + elif [ "${ret_wrapper}" -eq 255 ]; then + # qemu-nbd was not found + warn "No such file or directory: /usr/bin/qemu-nbd" + fi + emergency_shell -n "Error in $0" + return 1 + else + # all good, qemu-nbd is running, remember its pid + echo $qemu_nbd_pid > /tmp/qemu-nbd.pid + return 0 + fi + done + # fallback + return 1 +} +# helper to mount the qcow2-container per nbd +connect_qcow() { + # try to mount the locally exported qcow2-container using nbd-client + if /usr/bin/systemd-preserve-process-marker \ + nbd-client --persist 127.0.0.1 2000 /dev/nbd0; then + # it worked, lets set the symlink to /dev/root as dracut needs it + # later on to mount that device to the future root (/sysroot) + ln -sf /dev/nbd0 /dev/root + return 0 + else + # this is pretty bad, dracut would spawn an emergency later on + # since there is no /dev/root to mount. + # For debugging purposes, we drop an emergency shell ourselves + # if the mount fails. + warn "Could not mount /dev/nbd0 from 127.0.0.1:2000." + emergency_shell -n "Error in $0" + return 1 + fi +} +# +# END FUNCTION DEFINITIONS +############################################################################### + +# No main, use functions! |