1 files changed, 118 insertions, 0 deletions
diff --git a/testModule/scripts/setup-qcow2 b/testModule/scripts/setup-qcow2
new file mode 100755
index 00000000..ba1ef6b1
--- /dev/null
+++ b/testModule/scripts/setup-qcow2
@@ -0,0 +1,118 @@
+#!/usr/bin/bash
+
+# dracut-lib to use debugging functions
+command -v warn >/dev/null || . /lib/dracut-lib.sh
+
+###############################################################################
+# GLOBALS
+#
+# TODO make this configurable
+[ -f /opt/openslx/config ] && . /opt/openslx/config
+declare -rg DNBD3_DEVICE="/dev/dnbd0"
+declare -rg DNBD3_SERVER="132.230.4.1"
+declare -rg DNBD3_IMAGE="stage4/joe/centos7"
+declare -rg DNBD3_RID="4"
+#
+# 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 $0"
+		return 1
+	fi
+	return 0
+}
+
+# helper to create the qcow2 container file using
+# DNBD3_DEVICE as the base of the filesystem
+# /run/test.qcow2 as the writable file
+# (our future rootfs)
+create_qcow() {
+	# check if we already created the qcow2-container
+	[ -e /run/test.qcow2 ] && return 0
+
+	# we did not, let's create it
+	if ! qemu-img create -f qcow2 -o \
+		backing_file="$DNBD3_DEVICE",backing_fmt=qcow2 /run/test.qcow2; then
+		warn "Failed to create qcow2-Container from $DNBD3_DEVICE"
+		emergency_shell -n "Error in $0"
+		rm -f -- /run/test.qcow2
+		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 $(cat /tmp/qemu-nbd.pid) && return 0
+	fi
+	# since we use the wrapper, we need a little more logic to see if it runs
+	/usr/bin/systemd-preserve-process-marker \
+		/usr/bin/qemu-nbd -t -p 2000 /run/test.qcow2 &
+	# the wrapper returns 255 if the qemu-nbd binary is missing
+	local qemu_nbd_pid="$!"
+	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
+}
+#
+# END FUNCTION DEFINITIONS
+###############################################################################
+
+###############################################################################
+# MAIN CODE
+#
+#check_dnbd3 || return 1
+connect_dnbd3 || exit 1
+create_qcow || exit 1
+export_qcow || exit 1
+
+# all good, we are done :)
+exit 0