[vbox-src] rework RO/RW disk image setup

5 files changed, 98 insertions, 42 deletions

diff --git a/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/create_vbox_config.inc b/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/create_vbox_config.inc
index e432472f..75ec5ec3 100755
--- a/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/create_vbox_config.inc
+++ b/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/create_vbox_config.inc
@@ -7,7 +7,7 @@ create_vbox_config() {
 	declare -rg SLX_FLOPPY_UUID="$(gen_uuid)"
 
 	cat <<EOF > "${VBOX_ROOT}/VirtualBox.xml"
-<VirtualBox xmlns="http://www.innotek.de/VirtualBox-settings" version="1.12-linux">
+<VirtualBox xmlns="http://www.virtualbox.org/" version="1.12-linux">
 	<Global>
 		<ExtraData>
 			<ExtraDataItem name="GUI/Input/AutoCapture" value="true"/>
@@ -26,11 +26,7 @@ create_vbox_config() {
 			<MachineEntry uuid="{${MACHINE_UUID}}" src="Machines/${VM_CLEANNAME}/${VM_CLEANNAME}.xml"/>
 		</MachineRegistry>
 		<MediaRegistry>
-			<HardDisks>
-				<HardDisk uuid="{${HDD_UUID}}" location="${VBOX_HDD_LINK}" format="${VBOX_HDD_FORMAT}" type="${VBOX_HDD_TYPE}">
-					<HardDisk uuid="{${SNAPSHOT_UUID}}" location="${VBOX_SNAPSHOT_DIR}/{${SNAPSHOT_UUID}}.vdi" format="VDI" autoReset="true"/>
-				</HardDisk>
-			</HardDisks>
+			<HardDisks/>
 			<FloppyImages>
 				<Image uuid="{${SLX_FLOPPY_UUID}}" location="${SLX_FLOPPY_IMG}"/>
 			</FloppyImages>
diff --git a/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/init_core.inc b/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/init_core.inc
index 2ff95bbf..9f451cf9 100755
--- a/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/init_core.inc
+++ b/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/init_core.inc
@@ -228,7 +228,6 @@ Ihren Satelliten scheint VirtualBox nicht zu unterstützen." cleanexit 1
 		writelog "Failed to create '${VBOX_HDD_DIR}'."
 		cleanexit 1
 	fi
-	declare -rg VBOX_HDD_LINK="${VM_DISKFILE_RO}"
 	# Virtualbox configuration dir instead of $HOME/.VirtualBox
 	export VBOX_USER_HOME="${VBOX_ROOT}"
 
diff --git a/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/prepare_snapshot.inc b/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/prepare_snapshot.inc
index dcbff969..39a20bcd 100755
--- a/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/prepare_snapshot.inc
+++ b/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/includes/prepare_snapshot.inc
@@ -1,43 +1,104 @@
+# Extracts the uuid of the given vdi.
+# For VBox VDI Version 1.1, the 16-byte uuid is at offset 392
+# See: https://forums.virtualbox.org/viewtopic.php?p=29267#p29267
+extract_vdi_uuid() {
+	[ -z "$1" ] && return
+	od -An -t x1 -j 392 -N 16 "$1" | \
+		awk '{print $4$3$2$1"-"$6$5"-"$8$7"-"$9$10"-"$11$12$13$14$15$16}'
+}
+
+# Cleanup hook when the session stops
 delete_snapshot() {
 	rm -f "${VBOX_SNAPSHOT_DIR}/{${SNAPSHOT_UUID}}.vdi" || \
 		writelog "Could not cleanup snapshot file: ${VBOX_SNAPSHOT_DIR}/{${SNAPSHOT_UUID}}.vdi"
 }
-prepare_snapshot() {
-	declare -rg SNAPSHOT_UUID="34f617be-192a-46b3-a8ae-bce1029e093f"	# snapshot UUID is static
-	
-	# get UUID of disk image using od to get 16 bytes (starting at 392) and
-	# order them according to the VDI UUID format with awk
-	HDD_UUID="$(od -An -t x1 -j 392 -N 16 ${VBOX_HDD_LINK} | awk '{print $4$3$2$1"-"$6$5"-"$8$7"-"$9$10"-"$11$12$13$14$15$16}')"
+# TODO support snapshot for RW mode that are uploaded/on an NFS.
+prepare_disk_image_rw() {
+	# more of a placeholder function at this point :)
+	declare -rg VBOX_HDD_UUID="$HDD_UUID"
+}
+
+prepare_disk_image_ro() {
+	# extract the uuid of the snapshot...
+	local snapshot_path="${VBOX_PLUGIN_DIR}/snapshot.vdi"
+	local snapshot_tmp="${VBOX_SNAPSHOT_DIR}/${snapshot_path##*/}"
+	if [ -f "${snapshot_path}.gz" ]; then
+		gunzip -c "${snapshot_path}.gz" > "$snapshot_tmp"
+	elif [ -f "$snapshot_path" ]; then
+		cp -f -- "$snapshot_path" "$snapshot_tmp"
+	else
+		writelog "Could not find pre-generated snapshot file '$snapshot_path(|.gz)'."
+		# TODO fallback on creating a snapshot for this vbox image
+		# Note that this needs to be done after VBoxManage is aware of this VM...
+	fi
+	if [ -f "$snapshot_tmp" ]; then
+		declare -rg SNAPSHOT_UUID="$(extract_vdi_uuid "$snapshot_tmp")"
+	fi
+
+	# use temp disk as snapshot to get CoW
+	declare -rg VBOX_HDD_UUID="${SNAPSHOT_UUID}"
+
+	cp -f -- "$snapshot_tmp" "${VBOX_SNAPSHOT_DIR}/{${SNAPSHOT_UUID}}.vdi"
+
+	# TODO Use VBoxManage to determine the UUID of the disk image (making sure
+	# it is a VDI image) and patch it into the prepared snapshot VDI.
+	dd of="${VBOX_SNAPSHOT_DIR}/{${SNAPSHOT_UUID}}.vdi" \
+		seek=424 bs=1 count=16 conv=notrunc <<< "$HDD_UUID" || \
+			writelog "Could not patch snapshot file"
+
+	# TODO handle other formats...
+	# finally "register" the snapshot in the MediaRegistry
+	xmlstarlet ed -L -N x="http://www.virtualbox.org/" \
+		-s "//x:VirtualBox/x:Global/x:MediaRegistry/x:HardDisks/x:HardDisk[@uuid='{${HDD_UUID}}']" \
+		-t elem -n "HardDisk" --var newnode '$prev' \
+		-i '$newnode' -t attr -n "uuid" -v "{${SNAPSHOT_UUID}}" \
+		-i '$newnode' -t attr -n "location" -v "${VBOX_SNAPSHOT_DIR}/{${SNAPSHOT_UUID}}.vdi" \
+		-i '$newnode' -t attr -n "format" -v "VDI" \
+		-i '$newnode' -t attr -n "autoReset" -v "true" \
+		"${VBOX_ROOT}/VirtualBox.xml"
+
+	add_cleanup delete_snapshot
+}
+
+# Prepares the disk image specified as VM_DISKFILE_R[OW]
+# by run-virt's generic setup-image-access.inc
+# * RO -> use a CoW snapshot using VBox internals
+# * RW -> use it as is
+prepare_disk_image() {
+
+	# NOTE: either one is garanteed to be set by setup_image_access.inc
+	local handler
+	if [ -n "$VM_DISKFILE_RO" ]; then
+		declare -rg VBOX_HDD_LINK="$VM_DISKFILE_RO"
+		declare -rg VBOX_HDD_TYPE="Immutable"
+		handler="prepare_disk_image_ro"
+	elif [ -n "$VM_DISKFILE_RW" ]; then
+		declare -rg VBOX_HDD_LINK="$VM_DISKFILE_RW"
+		declare -rg VBOX_HDD_TYPE="Normal"
+		handler="prepare_disk_image_rw"
+	fi
+
+	# TODO Determine HDD storage format using VBoxManage
+	declare -rg VBOX_HDD_FORMAT="VDI"
+	declare -rg HDD_UUID="$(extract_vdi_uuid ${VBOX_HDD_LINK})"
 	if isempty HDD_UUID; then
 		writelog "Failed to extract VDI UUID of '${VBOX_HDD_LINK}'"
 		EXIT_TYPE="internal" EXIT_REASON="Konnte UUID der virtuellen Festplatte nicht extrahieren." cleanexit 1
 	fi
 
-	VBOX_HDD_FORMAT="VDI"
-
-	if isset VM_DISKFILE_RO; then
-		# use temp disk as snapshot to get CoW
-		VBOX_HDD_TYPE="Immutable"					# make disk immutable
-		VBOX_HDD_UUID=${SNAPSHOT_UUID}
-		< "${VBOX_PLUGIN_DIR}/empty-diff.vdi.gz" gunzip > "${VBOX_SNAPSHOT_DIR}/{${SNAPSHOT_UUID}}.vdi"
-		# patch the disk file uuid into the snapshot vdi file:
-		# We read from offset 424 in the source HDD and write the 16 bytes long UUID
-		# starting at offset 392 in the snapshot.
-		# TODO: This requires the image to be a vdi/vdh; Afaik, vbox supports vmdk,
-		# so this code would break in that case. Can we use the diskuuid we got via
-		# VBoxManage, convert to binary, and patch it
-		dd if=${VBOX_HDD_LINK} of="${VBOX_SNAPSHOT_DIR}/{${SNAPSHOT_UUID}}.vdi" seek=424 \
-			skip=392 bs=1 count=16 conv=notrunc || \
-				writelog "Could not patch snapshot file"
-		add_cleanup delete_snapshot
-	elif isset VM_DISKFILE_RW; then
-		# Image is already RW - easy
-		VBOX_HDD_TYPE="Normal"
-		VBOX_HDD_UUID=${HDD_UUID}
-	else
-		writelog "Neither VM_DISKFILE_RO nor VM_DISKFILE_RW defined!"
-		cleanexit 1
-	fi
+	# add the hard disk element to the "global" VirtualBox.xml
+	xmlstarlet ed -L -N x="http://www.virtualbox.org/" \
+		-s "//x:VirtualBox/x:Global/x:MediaRegistry/x:HardDisks" \
+		-t elem -n "HardDisk" --var newnode '$prev' \
+		-i '$newnode' -t attr -n "uuid" -v "{${HDD_UUID}}" \
+		-i '$newnode' -t attr -n "location" -v "$VBOX_HDD_LINK" \
+		-i '$newnode' -t attr -n "format" -v "$VBOX_HDD_FORMAT" \
+		-i '$newnode' -t attr -n "type" -v "$VBOX_HDD_TYPE" \
+		"${VBOX_ROOT}/VirtualBox.xml"
+
+	# now handle either RW or RO images
+	isset handler && "$handler"
+	return 0
 }
 
-call_post_source prepare_snapshot
+call_post_source prepare_disk_image
diff --git a/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/run-virt.include b/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/run-virt.include
index bca5c250..3ad81df5 100755
--- a/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/run-virt.include
+++ b/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/run-virt.include
@@ -28,12 +28,12 @@ run_plugin() {
 	# determine hardware limits based on guest OD
 	$(safesource "${VBOX_INCLUDE_DIR}/guest_hardware_limits.inc")
 
-	# prepare volatile rw layer for the disk image using a snapshot
-	$(safesource "${VBOX_INCLUDE_DIR}/prepare_snapshot.inc")
-
 	# create main virtualbox configuration
 	$(safesource "${VBOX_INCLUDE_DIR}/create_vbox_config.inc")
 
+	# prepare volatile rw layer for the disk image using a snapshot
+	$(safesource "${VBOX_INCLUDE_DIR}/prepare_snapshot.inc")
+
 	# finalize machine configuration
 	$(safesource "${VBOX_INCLUDE_DIR}/finalize_machine_config.inc")
 
diff --git a/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/empty-diff.vdi.gz b/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/snapshot.vdi.gz
index c6abbd57..c6abbd57 100644
--- a/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/empty-diff.vdi.gz
+++ b/core/modules/vbox-src/data/opt/openslx/vmchooser/plugins/virtualbox/snapshot.vdi.gz