###########################################################
# Include: Setup dnbd for image access, nfs/cifs fallback #
###########################################################

writelog "Now in setup_image_access.inc ..."

# Try to use dnbd3 to access the image
unset vm_diskfile
unset vm_revision
unset dnbd3_fuse_mount_point
unset dnbd3_tmplog
if ! which dnbd3-fuse; then
	writelog "Can't use dnbd3 as dnbd3-fuse binary is not in PATH"
elif [ -z "$SLX_DNBD3_SERVERS" ] || [ "x$SLX_VM_DNBD3" != "xyes" ]; then
	writelog "Can't use dnbd3 as no servers are given in config, or SLX_VM_DNBD3 is not set to yes"
else
	# Mount path for images mounted with dnbd3-fuse
	dnbd3_fuse_mount_point="$TMPDIR/dnbd3fuse.mnt"
	mkdir -p "${dnbd3_fuse_mount_point}"
	# start dnbd3-fuse in subshell
	dnbd3_tmplog="$TMPDIR/dnbd3fuse.log"
	dnbd3_exitflag="$TMPDIR/dnbd3exit$RANDOM"
	rm -f -- "$dnbd3_exitflag"
	(
		dnbd3-fuse -f -o allow_other,max_readahead=262144 -h "$SLX_DNBD3_SERVERS" -i "${imgrelpath}" "${dnbd3_fuse_mount_point}" > "$dnbd3_tmplog" 2>&1
		RET=$?
		touch "$dnbd3_exitflag"
		if [ "$RET" != "0" ]; then
			writelog "dnbd3-fuse stopped working (Exit code $RET)"
			slxlog "virt-dnbd3-fuse" "dnbd3-fuse stopped/refused serving '${imgrelpath}' from '${SLX_DNBD3_SERVERS}' with error code: $RET" "${dnbd3_tmplog}"
		fi
	) &
	# give it a bit of time
	usleep 250000
	# check if we have the image
	for TIMEOUT in 0.5 1 1 OUT; do
		if [ -r "${dnbd3_fuse_mount_point}/img" ]; then
			vm_revision="$(grep -m 1 "^Revision:" "${dnbd3_fuse_mount_point}/status" | cut  -d" " -f2)"
			vm_diskfile="${dnbd3_fuse_mount_point}/img"
			writelog "DNBD3: $imgrelpath on $vm_diskfile with rid $vm_revision"
			vmpath="$vm_diskfile"
			break
		fi
		[ "$TIMEOUT" = "OUT" -o -e "$dnbd3_exitflag" ] && break
		sleep "$TIMEOUT"
	done

	if [ -z "$vm_diskfile" ]; then
		slxlog "virt-dnbd3" "No dnbd3 server for ${imgrelpath} found, trying NFS/CIFS..." "$dnbd3_tmplog"
		writelog "No working dnbd3 server found :-("
	fi
fi

# $vm_diskfile will be empty if dnbd3 is not used or failed. Let's try to fall back to NFS/CIFS via file system
if [ -z "$vm_diskfile" ]; then
	new_vmpath=$(ls "${vmpath}.r"* | grep -E -o '\.r[0-9]+$' | grep -o -E '[0-9]+' | sort -n | tail -n 1)
	[ -n "$new_vmpath" ] && vmpath="${vmpath}.r${new_vmpath}"
	vm_diskfile="$vmpath"
fi

# Check if virtual machine container file exists
if ! [ -e "${vmpath}" ]; then
	slxlog "virt-image-missing" "VM image $vmpath not found!"
	writelog "Virtual machine image ${vmpath} not found!"
	error_user "Das Image für die gewählte Virtuelle Maschine konnte nicht gefunden werden.
Versuchen Sie zunächst, den Computer komplett neu zu starten. Sollte das Problem bestehen bleiben, wenden Sie sich bitte an den Support."
	cleanexit 1
fi

writelog "Virtual machine disk file: $vm_diskfile"