migrate to pi-hole v6 and alpine container image

docker-build/unbound-entrypoint.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+# Start unbound 
+echo "  [i] Starting Unbound"
+/usr/sbin/unbound -d -c /etc/unbound/unbound.conf.d/pihole.conf &
+# Get most recent process id for error checking
+UNBOUND_PID=$!
+
+# Wait for a second and check if unbound is running
+sleep 1
+if [ -d "/proc/$UNBOUND_PID" ]; 
+then
+    echo "  [i] Unbound started successfully."
+else
+    echo "  [i] Unbound startup failed."
+    echo "  [i] Take a look at /var/log/unbound/unbound.log"
+fi
+
+# Start pi-hole
+exec /usr/bin/start.sh