[run-virt] Add hook system, remove legacy code

6 files changed, 164 insertions, 132 deletions

diff --git a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/download_vm_metadata.inc b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/download_vm_metadata.inc
index 17b679ea..dd3f63e3 100644
--- a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/download_vm_metadata.inc
+++ b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/download_vm_metadata.inc
@@ -6,16 +6,32 @@
 # Legacy mode: As runvirt has been before.
 # New mode: uuid in xml _and_ vmx given via http.
 download_metadata() {
-	local TRIES EXTRA_ERROR WLOG TMPFILE RET ERRCODE CMDLINE
+	local EXTRA_ERROR=
+	declare -rg TMPCONFIG="$CONFDIR/vmx"
+
+	# Run hooks
+	if ! run_hooks "download" "$CONFDIR"; then
+		# No hooks found
+		download_metadata_default
+	fi
+	[ -s "$TMPCONFIG" ] && return 0
+	# Seems we are in legacy mode, which is no longer supported. Warn user and exit
+	EXIT_TYPE="user" EXIT_REASON="msg.vm.no-metadata
+Die Metadaten der Lehrumgebung konnten nicht vom bwLehrpool-Satelliten
+heruntergeladen werden. Bitte versuchen Sie es in wenigen Minuten erneut
+und wenden Sie sich an den Support, wenn das Problem bestehen bleibt.
+$EXTRA_ERROR
+" cleanexit 1
+}
+
+download_metadata_default() {
+	local TRIES WLOG TMPFILE RET ERRCODE CMDLINE
 	# Sanity checks
-	if ! check_dep wget; then
+	if ! check_dep curl; then
 		writelog "Could not find 'wget' in PATH: $PATH"
 		EXIT_TYPE="internal" EXIT_REASON="Fehlendes Dienstprogramm 'wget'!" cleanexit 1
 	fi
 
-	writelog "Detecting current/legacy mode..."
-	declare -rg TMPCONFIG="$CONFDIR/vmx"
-
 	# Try new unified .tar.gz way
 	TMPFILE="$TMPDIR/metadata.tgz"
 	WLOG="$TMPDIR/wget-metadata.log"
@@ -26,51 +42,14 @@ download_metadata() {
 	RET=$?
 	if [ "$RET" = 0 ] && [ -n "$ERRCODE" ] && [ "$ERRCODE" -ge 200 ] && [ "$ERRCODE" -lt 300 ]; then
 		# Success, see if data is usable
-		if tar -C "$CONFDIR" -x -f "$TMPFILE" && [ -s "$CONFDIR/vmx" ]; then
+		if tar -C "$CONFDIR" -x -f "$TMPFILE" && [ -s "$TMPCONFIG" ]; then
 			return 0
 		fi
 		rm -rf -- "$TMPFILE"
-		writelog "Extracting metadata.tgz failed. Trying legacy mode."
+		writelog "Extracting metadata.tgz failed. Cannot start VM."
 	else
-		writelog "Downloading metadata.tgz failed (HTTP $ERRCODE). Trying legacy mode."
-		#slxlog --delete "run-virt-wget" "Downloading MetaData failed" "$WLOG"
+		writelog "Downloading metadata.tgz failed (HTTP $ERRCODE). Cannot start VM." "$WLOG"
 	fi
-
-	TRIES=0
-	while [ "$TRIES" -lt 3 ]; do
-		TRIES=$(( TRIES + 1 ))
-		writelog "wget try $TRIES"
-		WLOG="$TMPDIR/wget-${TRIES}.log"
-		if wget -T 6 -O "$TMPCONFIG" "${url_lecture_config}" &>"$WLOG"; then
-			rm -f -- "$WLOG"
-			writelog "Downloaded VM description from '${url_lecture_config}' successfully."
-			if [ -s "$TMPCONFIG" ]; then
-				# Downloaded a non-zero VM description file, all good
-				return 0
-			else
-				writelog "Server sent zero byte virtual machine description file."
-				EXTRA_ERROR="(Der Server hat eine leere Antwort gesendet)"
-			fi
-		else
-			ERRCODE=$(grep -m1 -o -E '\b[0-9]{3}\b' "$WLOG")
-			if [ -n "$ERRCODE" ]; then
-				EXTRA_ERROR="(HTTP Error Code $ERRCODE)"
-			else
-				EXTRA_ERROR="(Der Server ist nicht erreichbar)"
-			fi
-			writelog "wget failed."
-		fi
-	done
-
-	slxlog --delete "run-virt-wget" "Downloading VMX/Metadata failed" "$WLOG"
-
-	# Seems we are in legacy mode, which is no longer supported. Warn user and exit
-	EXIT_TYPE="user" EXIT_REASON="msg.vm.no-metadata
-Die Metadaten der Lehrumgebung konnten nicht vom bwLehrpool-Satelliten
-heruntergeladen werden. Bitte versuchen Sie es in wenigen Minuten erneut
-und wenden Sie sich an den Support, wenn das Problem bestehen bleibt.
-$EXTRA_ERROR
-" cleanexit 1
 }
 
 ## Main ##
diff --git a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/load_configs.inc b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/load_configs.inc
index 0f1fab39..7a132fcc 100644
--- a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/load_configs.inc
+++ b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/load_configs.inc
@@ -17,9 +17,6 @@ load_configs() {
 
 	# Load general virtualization information
 	$(safesource --exit "$VMCHOOSER_CONF_DIR/virtualization.conf")
-	
-	# Load general openslx config
-	$(safesource --exit "/opt/openslx/config")
 
 	# Load config for resource URLs
 	$(safesource "$VMCHOOSER_CONF_DIR/resource_urls.conf")
diff --git a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/setup_image_access.inc b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/setup_image_access.inc
index ea8afc7e..cc921228 100644
--- a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/setup_image_access.inc
+++ b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/setup_image_access.inc
@@ -85,29 +85,25 @@ setup_fallback() {
 	readonly VM_DISKFILE_RO
 }
 
-setup_jambo() {
-	declare -r CMDLOG="$TMPDIR/sshfs.jambo"
-	declare -rg CLIENTPARTITION_ADMIN="/var/lib/vmware_admin"
-	#declare -r UPLOAD_KEYFILE="/var/lib/uploaduser"
-	#sudo -n sshfs "uploaduser@$JAMBOSERVER:/vms/bwlehrpool_store" "$CLIENTPARTITION_ADMIN" -o allow_other -o PreferredAuthentications=publickey -o IdentityFile="$UPLOAD_KEYFILE" -o IdentitiesOnly=yes &> "$CMDLOG"
-	sudo -n sshfs "uploaduser@$JAMBOSERVER:/vms/bwlehrpool_store" "$CLIENTPARTITION_ADMIN" -o allow_other -o PreferredAuthentications=publickey &> "$CMDLOG"
-	RET=$?
-	if [ "$RET" != "0" ]; then
-		writelog "SSHFS Failed
-		$(cat "$CMDLOG")"
-		EXIT_TYPE="user" EXIT_REASON="Schreibbarer VM-Speicher konnte nicht eingebunden werden. Adminmodus fehlgeschlagen." cleanexit 1
-	fi
-	declare -rg VM_DISKFILE_RW="$CLIENTPARTITION_ADMIN/$SRC_IMG_RELATIVE"
-}
-
-
 ## MAIN PART / Sanity checks ##
 setup_image_access() {
 	writelog "Setting up virtual hard disk access for virtualizer/emulator ..."
+	unset VM_DISKFILE_RO VM_DISKFILE_RW
+	declare -g VM_DISKFILE_RO VM_DISKFILE_RW
+
+	run_hooks "image-access"
 
-	if [ "$VMCHOOSER_ADMIN_MODE" = "TRUE" ] && [ -n "$SLX_JAMBOSERVER" ]; then
-		setup_jambo
-		writelog "\tVM disk file RW:\t\t$VM_DISKFILE_RW"
+	if [ -n "$VM_DISKFILE_RW" ]; then
+		writelog "A hook in setup_image_access supplied a writable diskfile. Not running default setup."
+	elif [ -n "$VM_DISKFILE_RO" ]; then
+		writelog "A hook in setup_image_access supplied a read-only diskfile. Not running default setup."
+	else
+		setup_image_access_default
+	fi
+	readonly VM_DISKFILE_RO VM_DISKFILE_RW
+
+	if [ -n "$VM_DISKFILE_RW" ]; then
+		writelog "\tVM disk file (RW):\t\t$VM_DISKFILE_RW"
 		if ! [ -s "$VM_DISKFILE_RW" ]; then
 			writelog ".... not found!"
 			EXIT_TYPE="user" EXIT_REASON="Schreibbare VM nicht gefunden. Adminmodus fehlgeschlagen." cleanexit 1
@@ -116,12 +112,22 @@ setup_image_access() {
 			writelog ".... not writable!"
 			EXIT_TYPE="user" EXIT_REASON="VM-Image auf schreibbarem VM-Speicher nicht schreibbar. Adminmodus fehlgeschlagen." cleanexit 1
 		fi
-		return 0
+	elif [ -n "$VM_DISKFILE_RO" ]; then
+		writelog "\tVM disk file (RO):\t\t$VM_DISKFILE_RO"
+		if ! [ -s "$VM_DISKFILE_RO" ]; then
+			writelog ".... not found!"
+			EXIT_TYPE="user" EXIT_REASON="VM-Image nicht gefunden." cleanexit 1
+		fi
+		if ! [ -r "$VM_DISKFILE_RO" ]; then
+			writelog ".... not readable!"
+			EXIT_TYPE="user" EXIT_REASON="VM-Image nicht lesbar." cleanexit 1
+		fi
+	else
+		EXIT_TYPE="user" EXIT_REASON="Kein VM-Image Dateiname angegeben/gefunden." cleanexit 1
 	fi
-	
-	unset VM_DISKFILE_RO
-	declare -g VM_DISKFILE_RO
-	
+}
+
+setup_image_access_default() {
 	# See if we should setup dnbd3 image access at all
 	if ! check_dep dnbd3-fuse fusermount; then
 		writelog "\tCan't use dnbd3 as dnbd3-fuse/fusermount binaries are not in PATH"
@@ -141,14 +147,6 @@ setup_image_access() {
 		writelog "Trying fallback image access via NFS/CIFS..."
 		setup_fallback
 	fi
-	
-	# Check if we finally found a valid, readable container
-	if isempty VM_DISKFILE_RO || [ ! -r "${VM_DISKFILE_RO}" ]; then
-		writelog "Virtual machine image ${VM_DISKFILE_RO} not found!"
-		EXIT_TYPE="user" EXIT_REASON="Konnte virtuelle Festplatte der gewählten VM nicht finden!" cleanexit 1
-	fi
-	
-	writelog "\tVM disk file:\t\t${VM_DISKFILE_RO}"
 }
 
 call_post_source setup_image_access
diff --git a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/vmchooser_runvirt_functions.inc b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/vmchooser_runvirt_functions.inc
index 932c4aad..7b4554ea 100644
--- a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/vmchooser_runvirt_functions.inc
+++ b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt-includes/vmchooser_runvirt_functions.inc
@@ -220,6 +220,34 @@ translate() {
 	fi
 }
 
+##
+# run_hooks type args...
+# eg run_hooks "download" "$CONFDIR"
+# returns 100 if no hooks exist
+run_hooks() {
+	local dir file retval r
+	declare -a files
+	dir="$BASEDIR/hooks/${1}.d"
+	[ -d "$dir" ] || return 100
+	shift
+	files=( "${dir}"/* )
+	retval=100
+	for file in "${files[@]}"; do
+		[ -e "${file}" ] || continue
+		r=100
+		if [ "${file##*.}" = "sh" ] && [ -x "$file" ]; then
+			export TMPDIR IMGUUID USER
+			"$file" "$@"
+			r="$?"
+		elif [ "${file##.*}" = "inc" ]; then
+			. "$file"
+			r="$?"
+		fi
+		[ "$r" -lt "$retval" ] && retval="$r"
+	done
+	return "$retval"
+}
+
 ################# SOURCING FUNCTIONS #################
 # Wrapped 'source' that first checks for existence and
 # syntax before actually sourcing the given file.
diff --git a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt.d/setup_virtual_floppy.inc b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt.d/setup_virtual_floppy.inc
index e302bdd7..c077bb42 100644
--- a/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt.d/setup_virtual_floppy.inc
+++ b/core/modules/run-virt/data/opt/openslx/vmchooser/run-virt.d/setup_virtual_floppy.inc
@@ -4,7 +4,7 @@
 ## Functions ##
 setup_virtual_floppy() {
 	declare -rg SLX_FLOPPY_IMG="${TMPDIR}/floppy.img"
-	declare -rg TMPHOME="${HOME}"
+	declare -r TMPHOME="${HOME}"
 
 	# create floppy disk file + filesystem
 	dd "if=/dev/zero" "of=${SLX_FLOPPY_IMG}" count=1440 bs=1024
@@ -13,10 +13,15 @@ setup_virtual_floppy() {
 	
 	if [ -s "${TMPHOME}/.openslx/shares" ]; then
 		$(safesource "${TMPHOME}/.openslx/shares")
-	else
+	elif [ -s "/opt/openslx/inc/shares" ]; then
 		$(safesource "/opt/openslx/inc/shares")
 	fi
 
+	# Directory for files that go into the virtual floppy
+	declare -r FLOPPYDIR="$TMPDIR/floppy"
+	mkdir -p "$FLOPPYDIR"
+	chmod 0700 "$FLOPPYDIR"
+
 	if notempty SHARE_REMAP_MODE; then
 		local SHARE_REMAP_MODE_INI="$SHARE_REMAP_MODE"
 	else
@@ -25,24 +30,16 @@ setup_virtual_floppy() {
 	fi
 	notempty SHARE_CREATE_MISSING_REMAP || local SHARE_CREATE_MISSING_REMAP="1"
 	
-	# Legacy: openslx.exe expects HOSTRES.TXT
-	local RESOLUTION=$(xrandr | grep -o -E 'connected\s*(primary)?\s*[0-9]+x[0-9]+\+0\+0' \
-		| grep -o -E -m1 '[0-9]+x[0-9]+')
-	# TODO fallback if this fails? this is currently never checked...
-	cat > "${TMPDIR}/HOSTRES.TXT" <<-EOF
-	${RESOLUTION}
-	EOF
-	
 	# Create file for network shares to mount
-	declare -g SHARES="${TMPDIR}/shares.dat"
+	declare -g SHARES="${FLOPPYDIR}/shares.dat"
 	touch "${SHARES}"
 	chmod 0600 "${SHARES}"
 	if ! pwdaemon --query "${TMPHOME}/.pwsocket" > "${SHARES}"; then
-		slxlog "virt-pwdaemon" "Could not start pwdaemon"
+		slxlog "run-virt-pwdaemon" "Could not query pwdaemon"
 		echo -e '-\t-\t-\t-\t-' > "${SHARES}"
 	else
 		sed -i 's/^/192.168.101.1\t/' "${SHARES}" # TODO: Depending on nettype (in case we have != nat some day)
-		if [ "${SHARE_REMAP_MODE}" = 1 -o "${SHARE_REMAP_MODE}" = 2 ] && [ -e "${TMPHOME}/.openslx/home" ]; then
+		if [ "${SHARE_REMAP_MODE}" = 1 -o "${SHARE_REMAP_MODE}" = 2 ] && [ -s "${TMPHOME}/.openslx/home" ]; then
 			NETHOME=$(cat "${TMPHOME}/.openslx/home")
 			notempty SHARE_HOME_DRIVE || local SHARE_HOME_DRIVE="H:"
 			# Tab between items, so spaces can be used!
@@ -53,25 +50,22 @@ setup_virtual_floppy() {
 		done
 	fi
 
-	local NETSHARES="$CONFDIR/netshares"
-	local RUNSCRIPT="$CONFDIR/runscript"
-
+	declare -r NETSHARES="$CONFDIR/netshares"
+	declare -r RUNSCRIPT="$CONFDIR/runscript"
 	## Network shares
 	# openslx.exe expects network shares line in the following format:
 	#		<path> <letter> <shortcut> <username> <password>
 	# which is coincidentally the one we received from dmsd :)
-	if [ -f "$NETSHARES" ] || download_file "$url_lecture_netshares" "$NETSHARES"; then
-		if [ -s "${NETSHARES}" ]; then
-			# try to detect if we are running windows and replace '/' with '\'
-			# in an attempt to fix an improperly given samba path
-			cmd=(cat)
-			if [[ "$( tr '[A-Z]' '[a-z]' <<< ${VM_OS_TYPE})" = *windows* ]]; then
-				cmd=(tr / '\\')
-			fi
-			# replace the tag for the username, if present; the variable expansion escapes all ':' in $USER
-			sed -i "s:%loginuser%:${USER//:/\\:}:g" "${NETSHARES}"
-			< "${NETSHARES}"  "${cmd[@]}" >> "${SHARES}"
+	if [ -f "$NETSHARES" ] && [ -s "${NETSHARES}" ]; then
+		# try to detect if we are running windows and replace '/' with '\'
+		# in an attempt to fix an improperly given samba path
+		cmd=(cat)
+		if [[ "$( tr 'A-Z' 'a-z' <<< ${VM_OS_TYPE})" = *windows* ]]; then
+			cmd=(tr / '\\')
 		fi
+		# replace the tag for the username, if present; the variable expansion escapes all ':' in $USER
+		sed -i "s:%loginuser%:${USER//:/\\:}:g" "${NETSHARES}"
+		< "${NETSHARES}"  "${cmd[@]}" >> "${SHARES}"
 	fi
 
 	## Runscript
@@ -79,17 +73,15 @@ setup_virtual_floppy() {
 	# Check downloaded runscript and handle options like
 	# extension, visibility flag, ...
 	# options are 'key=value' pairs separated with ';'
-	if [ -f "$RUNSCRIPT" ] || download_file "$url_lecture_runscript" "$RUNSCRIPT"; then
-		if [ -s "$RUNSCRIPT" ]; then
-			IFS=$'\n'
-			for OPT in $(head -n 1 "$RUNSCRIPT" | tr ";" "\n"); do
-				KEY=$(cut -s -d '=' -f 1 <<< "${OPT^^}")
-				[ -n "$KEY" ] && OPTIONS["$KEY"]=$(cut -s -d '=' -f 2- <<< "$OPT")
-			done
-			unset IFS
+	if [ -f "$RUNSCRIPT" ] && [ -s "$RUNSCRIPT" ]; then
+		IFS=$'\n'
+		for OPT in $( head -n 1 "$RUNSCRIPT" | tr ";" "\n" ); do
+			KEY=$( cut -s -d '=' -f 1 <<< "${OPT^^}" )
+			[ -n "$KEY" ] && OPTIONS["$KEY"]="$( cut -s -d '=' -f 2- <<< "$OPT" )"
+		done
+		unset IFS
 
-			[ ${OPTIONS[EXT]} ] && [ "x${OPTIONS[EXT]:0:1}" != "x." ] && OPTIONS[EXT]=".${OPTIONS[EXT]}"
-		fi
+		[ -n "${OPTIONS[EXT]}" ] && [ "x${OPTIONS[EXT]:0:1}" != "x." ] && OPTIONS[EXT]=".${OPTIONS[EXT]}"
 	fi
 
 	# Default to muted
@@ -113,7 +105,14 @@ setup_virtual_floppy() {
 		SHARE_NO_HOME_WARN=0
 	fi
 
-	cat > "${TMPDIR}/openslx.ini" <<-EOF
+	# Legacy: openslx.exe expects HOSTRES.TXT
+	local RESOLUTION=$(xrandr | grep -o -E 'connected\s*(primary)?\s*[0-9]+x[0-9]+\+0\+0' \
+		| grep -o -E -m1 '[0-9]+x[0-9]+')
+	cat > "${FLOPPYDIR}/HOSTRES.TXT" <<-EOF
+	${RESOLUTION}
+	EOF
+
+	cat > "${FLOPPYDIR}/openslx.ini" <<-EOF
 	[openslx]
 	username=${UNAME}
 	resolution=${RESOLUTION}
@@ -135,35 +134,43 @@ setup_virtual_floppy() {
 	other=${SHARE_OTHER}
 	EOF
 	
-	# Copy all them there filez into floppy image
-	mcopy -i "${SLX_FLOPPY_IMG}" "${TMPDIR}/openslx.ini" "${TMPDIR}/HOSTRES.TXT" "${SHARES}" "${VMCHOOSER_DIR}/data/openslx.exe" "::/"
+	ln -n -s "${VMCHOOSER_DIR}/data/openslx.exe" "${FLOPPYDIR}/openslx.exe"
 	# If we have a kerberos ticket, copy that one too (TODO: Copy keytab too?)
 	if [ -n "$KRB5CCNAME" ]; then
 		kf=${KRB5CCNAME#FILE:}
 		kf=${kf#file:}
 		if [ -n "$kf" ] && [ -f "$kf" ]; then
-			mcopy -i "${SLX_FLOPPY_IMG}" "$kf" "::/krb5user.key"
+			ln -n -s "$kf" "${FLOPPYDIR}/krb5user.key"
 		fi
 	fi
-	# Copy guest configuration (with added information) config.xml to be accessed
-	# via virtual floppy
-	mcopy -i "${SLX_FLOPPY_IMG}" "$XML_FILE" "::/config.xml"
 	
-	# Copying linux directory:
-	mcopy -s -i "${SLX_FLOPPY_IMG}" "$VMCHOOSER_DIR/data/linux" "::/"
+	# Linux directory
+	ln -n -s "$VMCHOOSER_DIR/data/linux" "${FLOPPYDIR}/linux"
 	
 	# User supplied runscript
 	if [ -n "${OPTIONS[EXT]}" ]; then
 		sed -i '1d' "${RUNSCRIPT}"
-		mcopy -i "${SLX_FLOPPY_IMG}" "${RUNSCRIPT}" "::/runscript${OPTIONS[EXT]}"
+		ln -n -s "${RUNSCRIPT}" "${FLOPPYDIR}/runscript${OPTIONS[EXT]}"
 	fi
 	
 	# Admin supplied runscript(s)
 	if [ -d "${CONFDIR}/adminrun" ]; then
-		mcopy -s -i "${SLX_FLOPPY_IMG}" "${CONFDIR}/adminrun" "::/"
+		ln -n -s "${CONFDIR}/adminrun" "${FLOPPYDIR}/adminrun"
+	fi
+
+	# Hook
+	run_hooks "floppy" "$FLOPPYDIR"
+
+	local size="$( du -s -l -L "${FLOPPYDIR}" | awk '{print $1}' )"
+	if [ -n "$size" ] && [ "$size" -ge 1400 ]; then
+		writelog "WARNING: Floppydir contains $size kb of data, will most likely not fit..."
 	fi
 	
-	rm -f -- "${SHARES}" "${TMPDIR}/openslx.ini" "${TMPDIR}/HOSTRES.TXT"
+	if ! mcopy -s -i "${SLX_FLOPPY_IMG}" "${FLOPPYDIR}"/* "::/"; then
+		writelog "Error creating floppy image from ${FLOPPYDIR}"
+	elif ! $DEBUG; then
+		rm -rf -- "${FLOPPYDIR}"
+	fi
 }
 
 ## MAIN ##
diff --git a/core/modules/run-virt/data/opt/openslx/vmchooser/vmchooser-run_virt b/core/modules/run-virt/data/opt/openslx/vmchooser/vmchooser-run_virt
index d8f7d6ba..4a4b8f16 100755
--- a/core/modules/run-virt/data/opt/openslx/vmchooser/vmchooser-run_virt
+++ b/core/modules/run-virt/data/opt/openslx/vmchooser/vmchooser-run_virt
@@ -19,16 +19,39 @@
 #      tools and then include the specific plugin which configures the speci-
 #      fied virtualization tool.
 ################################################################################
-SELF=$(readlink -f "$0")
+SELF="$( readlink -f "${BASH_SOURCE[0]}" )"
+if [ -z "$SELF" ] || ! [ -f "$SELF" ]; then
+	SELF="$( readlink -f "$0" )"
+fi
+if [ -z "$SELF" ] || ! [ -f "$SELF" ]; then
+	slxlog "run-virt" "Cannot find SELF"
+	exit 1
+fi
+readonly SELF
+
+# Useless without this
+. /opt/openslx/config
+
+# Debug mode?
+if [ "x$1" = "x--debug" ]; then
+	shift
+	DEBUG=true
+elif [ "$SLX_DEBUG_MODE" = "ON" ] || grep -qE '\bdebug\b' "/proc/cmdline"; then
+	DEBUG=true
+else
+	DEBUG=false
+fi
 
 # This script expects the path to the xml file describing the VM to be started
 declare -rg XML_FILE="$1"
 
-# A path to the logfile can be given as second argument
+# A path to the logfile can be given as second argument (will be set later if empty)
 declare -g LOGFILE="$2"
 
 # Functions needed by vmchooser-run_virt (writelog(), cleanexit(), safesource())
-declare -rg RUN_VIRT_INCLUDE_DIR="$(dirname $SELF)/run-virt-includes"
+BASEDIR="$( dirname "${SELF}" )"
+RUN_VIRT_INCLUDE_DIR="${BASEDIR}/run-virt-includes"
+readonly BASEDIR RUN_VIRT_INCLUDE_DIR
 if ! source "${RUN_VIRT_INCLUDE_DIR}/vmchooser_runvirt_functions.inc"; then
 	slxlog "run-virt" "Could not source ${RUN_VIRT_INCLUDE_DIR}/vmchooser_runvirt_functions.inc"
 	exit 1