Haproxy logs to logstash
UDP Only!!!
Hostname Header from SNI: https://discourse.haproxy.org/t/log-sni-in-tcp-mode/1534
HTTP Headers: https://gist.githubusercontent.com/haproxytechblog/fd1b3691893183dac7151c213fc9950d/raw/d508e37b7966c464e10e9616d9624fbdf9513a0e/blog20121029-08.cfg