#!/bin/bash
# Needs full bash

. /opt/openslx/config

[ -z "${SLX_STAGE4}" ] && { echo "SLX_STAGE4 is not set in /opt/openslx/config." && exit 1; }

MOUNTPOINT="/opt/openslx/mnt/stage4"
mkdir -p "$MOUNTPOINT"

if [[ "$SLX_STAGE4" == dnbd3* ]]; then
	# dnbd3 it is
	if [ -z "${SLX_DNBD3_SERVERS}${SLX_DNBD3_PRIO_SERVERS}" ]; then
		slxlog --echo "mount-stage4" "dnbd3 stage4 configured, but SLX_DNBD3(_PRIO)_SERVERS empty or not set in /opt/openslx/config."
		exit 1
	fi
	# Determine revision
	if [ -z "$SLX_STAGE4_RID" ] || echo "$SLX_STAGE4_RID" | grep -v -q -E "^[0-9]+$"; then
		SLX_STAGE4_RID="0"
	fi
	# Randomize list
	SERVERS=$(for SERVER in $SLX_DNBD3_SERVERS; do echo "$RANDOM $SERVER"; done | sort -u | sed -r 's/^[0-9]+ //')
	IMAGE=$(echo $SLX_STAGE4 | awk '{printf $2}')
	[ -e /var/run/dnbd3.socket ] || sleep 2 # Ugly, service should only start when dnbd3 daemon is up and running
	RET=1337
	for SRV in $SLX_DNBD3_PRIO_SERVERS $SERVERS; do
		echo "Requesting $IMAGE from $SRV"
		dnbd3=$(dnbd3-client -h "$SRV" -i "$IMAGE" -r "$SLX_STAGE4_RID")
		RET=$?
		[ "$RET" -eq "0" ] && break
		echo "... didn't work ($RET)"
		sleep 1
	done
	if [ "$RET" -ne "0" ]; then
		slxlog --echo "mount-stage4" "Could not get stage4 via dnbd3 ($IMAGE : $SLX_STAGE4_RID) ($SLX_DNBD3_PRIO_SERVERS / $SERVERS)"
		exit $RET
	fi
	echo "Mounting $dnbd3 to $MOUNTPOINT"
	if ! mount -t squashfs -o ro "$dnbd3" "$MOUNTPOINT"; then
		slxlog --echo "mount-stage4" "Could not mount stage4 from '$dnbd3' to '$MOUNTPOINT' ($SRV, $IMAGE)"
		exit 1
	fi
else
	# Try nfs
	echo "Mounting ${SLX_STAGE4} to $MOUNTPOINT"
	if ! mount -t nfs -o ro,async,nolock,vers=3 "$SLX_STAGE4" "$MOUNTPOINT"; then
		slxlog --echo "mount-stage4" "Could not mount stage4 from '$SLX_STAGE4' to '$MOUNTPOINT'"
		exit 1
	fi
fi

echo "Appending $MOUNTPOINT to /"
if mount -o "remount,append:$MOUNTPOINT=ro" /; then

	# addons can trigger ldconfig, hence
	# make sure no ldconfig is running before copying the real ld cache
	while ps aux|grep -v grep|grep -q ldconfig; do
		sleep 1
	done
	cp -r "${MOUNTPOINT}/"etc/ld.* /etc/ || echo "Could not really copy full blown ldconfig from stage4 to live system"
else
	slxlog --echo "mount-stage4" "Could not append mounted stage4 at '$MOUNTPOINT' to aufs at /"
	exit 1
fi

# dbus reload needed eg. for gnome etc. and perhaps other service files which stage4 needs:
systemctl reload dbus.service

exit 0