Lua

WebSocket Connect through HTTP Proxy

See more WebSocket Examples

This example shows how to establish a WebSocket connection through an HTTP proxy server. Lua

local chilkat = require("chilkat")

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

-- --------------------------------------------------
-- This example borrows the code from the REST using HTTP Proxy example.
-- We first use the Chilkat Socket object to establish a connection to the WebSocket server through an HTTP proxy.
-- Next, the Rest object uses the Socket object for its connection.
-- Finally, the WebSocket object uses the Rest object for its connection.
--

local rest = chilkat.Rest.new()
local socket = chilkat.Socket.new()

-- Set the HTTP proxy domain or IP address, and port.
socket.http_proxy_hostname = "192.168.1.79"
socket.http_proxy_port = 808

-- Provide authentication to the HTTP proxy, if needed.
socket.http_proxy_username = "HTTP_PROXY_LOGIN"
socket.http_proxy_password = "HTTP_PROXY_PASSWORD"
socket.http_proxy_auth_method = "Basic"

-- Indicate that HTTP requests (i.e. the WebSocket opening handshake) will be sent over the socket.
-- This is important for how the HTTP proxy connection is established.
socket.http_proxy_for_http = true

-- Connect to the websocket server through the HTTP proxy.
local bTls = false
local port = 80
local maxWaitMs = 5000
local success = socket:connect("some-websocket-server.com", port, bTls, maxWaitMs)
if not success then
    print("Connect Failure Error Code: " .. socket.connect_fail_reason)
    print(socket.last_error_text)
    return
end

-- Tell the Rest object to use the connected socket.
success = rest:use_connection(socket, true)
if not success then
    print(rest.last_error_text)
    return
end

local ws = chilkat.WebSocket.new()

-- Tell the WebSocket to use this connection.
success = ws:use_connection(rest)
if not success then
    print(ws.last_error_text)
    return
end

-- Add the standard WebSocket open handshake headers that will be needed.
-- (This adds the required HTTP request headers to the rest object.)
ws:add_client_headers()

-- Add any additional headers that might be desired.
-- Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
rest:add_header("Sec-WebSocket-Protocol", "x-some-websocket-subprotocol")
rest:add_header("Origin", "http://some-websocket-server.com")

-- Do the open handshake.
local responseBody = rest:full_request_no_body("GET", "/something")
if not rest.last_method_success then
    print(rest.last_error_text)
    return
end

-- If successful, the HTTP response status code should be 101,
-- and the response body will be empty. (If it failed, we'll have a look
-- at the response body..)
local statusCode = rest.response_status_code
print("Response status code: " .. statusCode)

if statusCode ~= 101 then
    print(responseBody)
    print("-- Failed because of unexpected response status code.")
    return
end

-- We have the expected 101 response, so let's now validate the
-- contents of the response, such as the value sent by the server in the
-- Sec-WebSocket-Accept header.
success = ws:validate_server_handshake()
if not success then
    print(ws.last_error_text)
    return
end

print("WebSocket connection successful.")

-- The application may now begin sending and receiving frames on the WebSocket connection.
-- (At this point, we're done with the rest and socket objects...)

print("Success.")