can't connect websocket when start rails with -d.

[famince]

it's ok when start rails with command: rails s -b0.0.0.0 -p8080.

but start rails with command：rails s -b0.0.0.0 -p8080 -d
can't connect to websocket

server:
config/initializers/websocket.rb
EM.run {
EM::WebSocket.run(:host => "0.0.0.0", :port => 8082) do |ws|
ws.onopen { |handshake|
puts "WebSocket connection open"

  # Access properties on the EM::WebSocket::Handshake object, e.g.
  # path, query_string, origin, headers

  # Publish message to the client
  ws.send "Hello Client, you connected to #{handshake.path}"
}

ws.onclose { puts "Connection closed" }

ws.onmessage { |msg|
  puts "Recieved message: #{msg}"
  ws.send "Pong: #{msg}"
}

end
}

client:
html file

<script> var ws = new WebSocket("ws://*.*.*.*:8082"); ws.onopen = function() { alert("websocket is connected..."); ws.send('send from browser'); }; ws.onmessage = function (evt) { var msg = evt.data; alert("Message is received..." + msg); }; ws.onclose = function() { alert("Connection is closed..."); }; </script> websocket test