xenial image check

Change-Id: I986a2054f92fa0aff24e301f700a663784218258
diff --git a/config-drive/master_config.sh b/config-drive/master_config.sh
index 485d1df..3597312 100644
--- a/config-drive/master_config.sh
+++ b/config-drive/master_config.sh
@@ -61,6 +61,11 @@
     maas ${PROFILE} boot-source-selections create 1 os="ubuntu" release="xenial" arches="amd64" subarches="*" labels="*"
     maas ${PROFILE} boot-resources import
   fi
+  while [ ! -d /var/lib/maas/boot-resources/current/ubuntu/amd64/generic/xenial ]
+  do
+    sleep 10
+    echo "WARNING: Image is still not ready"
+  done
 }
 
 ### Body