Environment variable EXPECT_PROXY_PROTOCOL to indicate that the proxy header is expected. If set, connections should only be allowed through stunnel/haproxy with proxy protocol enabled.
Log new connections and client ip/port on connect and disconnect
This adds support for proxy protocol used by e.g. stunnel and haproxy to relay original client ip information to application behind them (http://haproxy.1wt.eu/download/1.5/doc/proxy-protocol.txt)