specify ubuntu as the ssh user
diff --git a/princeton-setup.yml b/princeton-setup.yml
index da9d9a6..47895f6 100644
--- a/princeton-setup.yml
+++ b/princeton-setup.yml
@@ -2,6 +2,7 @@
 # Play: set up head node
 # Assumes basic /etc/ansible/hosts file
 - hosts: head
+  user: ubuntu
   sudo: yes
   vars:
     # Each OpenCloud cluster needs a unique mgmt_net_prefix