neil@nj-ubuntu:~/calico$ juju ssh etcd-local-proxy/0
Welcome to Ubuntu 16.04 LTS (GNU/Linux 4.4.0-28-generic x86_64)
[...]

ubuntu@ip-172-31-48-169:~$ etcdctl ls /
Error:  client: etcd cluster is unavailable or misconfigured
error #0: x509: certificate signed by unknown authority

ubuntu@ip-172-31-48-169:~$