make IPv4/IPv6 checking more robust in gravity

gravity.sh

@@ -42,7 +42,7 @@ else
 fi
 
 #Remove the /* from the end of the IPv4addr.
-IPv4addr=${IPv4_address%/*}
+IPv4_address=${IPv4_address%/*}
 
 # Variables for various stages of downloading and formatting the list
 basename=pihole
@@ -246,17 +246,30 @@ gravity_hostFormat() {
 	else
 		echo "::: Error: Unable to determine fully qualified domain name of host"
 	fi
-	# If there is a value in the $piholeIPv6, then IPv6 will be used, so the awk command modified to create a line for both protocols
-	if [[ -n "${IPv6_address}" ]];then
-		# Add hostname and dummy domain to the top of gravity.list to make ping result return a friendlier looking domain! Also allows for an easy way to access the Pi-hole admin console (pi.hole/admin)
-		echo -e "$IPv4addr $hostname\n$IPv6_address $hostname\n$IPv4addr pi.hole\n$IPv6_address pi.hole" > ${piholeDir}/${accretionDisc}
-		cat ${piholeDir}/${eventHorizon} | awk -v ipv4addr="$IPv4addr" -v ipv6addr="$IPv6_address" '{sub(/\r$/,""); print ipv4addr" "$0"\n"ipv6addr" "$0}' >> ${piholeDir}/${accretionDisc}
-	else
-		# Otherwise, just create gravity.list as normal using IPv4
-		# Add hostname and dummy domain to the top of gravity.list to make ping result return a friendlier looking domain! Also allows for an easy way to access the Pi-hole admin console (pi.hole/admin)
-		echo -e "$IPv4addr $hostname\n$IPv4addr pi.hole" > ${piholeDir}/${accretionDisc}
-		cat ${piholeDir}/${eventHorizon} | awk -v ipv4addr="$IPv4addr" '{sub(/\r$/,""); print ipv4addr" "$0}' >> ${piholeDir}/${accretionDisc}
-	fi
+
+    # Check vars from setupVars.conf to see if we're using IPv4, IPv6, Or both.
+	if [[ -n "${IPv4_address}" && -n "${IPv6_address}" ]];then
+
+        # Both IPv4 and IPv6
+		echo -e "$IPv4_address $hostname\n$IPv6_address $hostname\n$IPv4_address pi.hole\n$IPv6_address pi.hole" > ${piholeDir}/${accretionDisc}
+		cat ${piholeDir}/${eventHorizon} | awk -v ipv4addr="$IPv4_address" -v ipv6addr="$IPv6_address" '{sub(/\r$/,""); print ipv4addr" "$0"\n"ipv6addr" "$0}' >> ${piholeDir}/${accretionDisc}
+
+    elif [[ -n "${IPv4_address}" && -z "${IPv6_address}" ]];then
+
+        # Only IPv4
+        echo -e "$IPv4addr $hostname\n$IPv4addr pi.hole" > ${piholeDir}/${accretionDisc}
+		cat ${piholeDir}/${eventHorizon} | awk -v ipv4addr="$IPv4_address" '{sub(/\r$/,""); print ipv4addr" "$0}' >> ${piholeDir}/${accretionDisc}
+
+    elif [[ -z "${IPv4_address}" && -n "${IPv6_address}" ]];then
+
+        # Only IPv6
+        echo -e "$IPv6_address $hostname\n$IPv6_address pi.hole" > ${piholeDir}/${accretionDisc}
+		cat ${piholeDir}/${eventHorizon} | awk -v ipv6addr="$IPv6_address" '{sub(/\r$/,""); print ipv6addr" "$0}' >> ${piholeDir}/${accretionDisc}
+
+    elif [[ -z "${IPv4_address}" && -z "${IPv6_address}" ]];then
+        echo "::: No IP Values found! Please run 'pihole -r' and choose reconfigure to restore values"
+	    exit 1
+    fi
 
 	# Copy the file over as /etc/pihole/gravity.list so dnsmasq can use it
 	cp ${piholeDir}/${accretionDisc} ${adList}