sudo letsencrypt renew --agree-tos
2016-10-01 23:19:38,838:WARNING:letsencrypt.cli:Attempting to renew cert from /etc/letsencrypt/renewal/xxx.conf produced an unexpected error: The requested apache plugin does not appear to be installed. Skipping.
All renewal attempts failed. The following certs could not be renewed:
1 renew failure(s), 0 parse failure(s)