HAProxy configuration with Websocket support

haproxy.cfg

global
  maxconn     4096 # Total Max Connections. This is dependent on ulimit
  nbproc      2
  log         127.0.0.1 local1 notice

defaults
  mode        http
  log         global

frontend all 0.0.0.0:80
  timeout client 86400000
  default_backend www_backend
  acl is_websocket hdr(Upgrade) -i WebSocket
  acl is_websocket hdr_beg(Host) -i ws
  acl host_bibliaolvaso hdr_sub(Host) -i bibliaolvaso.hu
  acl host_todomvc hdr_sub(Host) -i todomvc

  use_backend bibliaolvaso_backend if is_websocket host_bibliaolvaso
  use_backend todomvc_backend if is_websocket host_todomvc

backend www_backend
  balance roundrobin
  option forwardfor # This sets X-Forwarded-For
  timeout server 86400000
  timeout connect 4000
  server nginx localhost:81

backend bibliaolvaso_backend
  balance roundrobin
  option forwardfor # This sets X-Forwarded-For
  timeout queue 5000
  timeout server 86400000
  timeout connect 5000
  server bibliaolvaso localhost:7777

backend todomvc_backend
  balance roundrobin
  option forwardfor # This sets X-Forwarded-For
  timeout queue 5000
  timeout server 86400000
  timeout connect 5000
  server todomvc localhost:3003

Please put proper comments so that if would be easy to understand what configuration line is playing what role.

@indrajeet0510 lmfao

acl is_websocket hdr(Upgrade) -i WebSocket
acl is_websocket hdr_beg(Host) -i ws

Still useful 8 years later. Thank you!