Add logging of IP address and process number

At the beginning of each client connection, log the IP address along
with Erlang's process number associated with the socket.

This allows us to pinpoint clients who encounter problems and help
them out.

apps/epp_proxy/src/epp_tls_worker.erl

@@ -40,6 +40,7 @@ handle_cast(serve,
 	    State = #state{socket = Socket,
 			   session_id = _SessionId}) ->
     {ok, {PeerIp, _PeerPort}} = ssl:peername(Socket),
+    log_opened_connection(PeerIp),
     case ssl:handshake(Socket) of
       {ok, SecureSocket} ->
 	  NewState = state_from_socket(SecureSocket, State),
@@ -168,6 +169,11 @@ log_on_invalid_handshake(Ip, Error) ->
 	       [ReadableIp, Error]),
     exit(normal).
 
+log_opened_connection(Ip) ->
+    ReadableIp = epp_util:readable_ip(Ip),
+    lager:info("New client connection. IP: ~s, Process: ~p.~n",
+	       [ReadableIp, self()]).
+
 %% Extract state info from socket. Fail if you must.
 state_from_socket(Socket, State) ->
     {ok, PeerCert} = ssl:peercert(Socket),