haproxy.cfg

global
  log 127.0.0.1 local0
  log 127.0.0.1 local1 notice

defaults
  mode http
  log global
  option httplog
  option  http-server-close
  option  dontlognull
  option  redispatch
  option  contstats
  retries 3
  backlog 10000
  timeout client          25s
  timeout connect          5s
  timeout server          25s
# timeout tunnel available in ALOHA 5.5 or HAProxy 1.5-dev10 and higher
  timeout tunnel        3600s
  timeout http-keep-alive  1s
  timeout http-request    15s
  timeout queue           30s
  timeout tarpit          60s
  default-server inter 3s rise 2 fall 3
  option forwardfor

listen stats
  bind 0.0.0.0:70
  stats enable
  stats uri /

frontend balancer
  bind *:80
  mode http
  default_backend http_servers

  acl is_websocket path_beg /socket
  acl is_websocket hdr(Upgrade) -i websocket

  use_backend ws_servers if is_websocket

backend http_servers
  mode http
  option forwardfor
  # http-request set-header X-Forwarded-Port %[dst_port]
  balance roundrobin
  server phoenix-1 127.0.0.1:4000 check
  server phoenix-2 127.0.0.1:4100 check
  server phoenix-3 127.0.0.1:4200 check
  # option httpchk OPTIONS * HTTP/1.1\r\nHost:\ localhost
  # option httpchk GET /
  # http-check expect status 200

backend ws_servers
  balance roundrobin
  option http-server-close
  option forceclose
  server phoenix-1 127.0.0.1:4000 weight 1 maxconn 1024 check
  server phoenix-2 127.0.0.1:4100 weight 1 maxconn 1024 check
  server phoenix-3 127.0.0.1:4200 weight 1 maxconn 1024 check