proxy_chain.js

const ProxyChain = require("proxy-chain")

const server = new ProxyChain.Server({
  // Port where the server will listen. By default 8000.
  port: 8000,

  // Enables verbose logging
  verbose: true,

  // Custom user-defined function to authenticate incoming proxy requests,
  // and optionally provide the URL to chained upstream proxy.
  // The function must return an object (or promise resolving to the object) with the following signature:
  // { requestAuthentication: Boolean, upstreamProxyUrl: String }
  // If the function is not defined or is null, the server runs in simple mode.
  // Note that the function takes a single argument with the following properties:
  // * request      - An instance of http.IncomingMessage class with information about the client request
  //                  (which is either HTTP CONNECT for SSL protocol, or other HTTP request)
  // * username     - Username parsed from the Proxy-Authorization header. Might be empty string.
  // * password     - Password parsed from the Proxy-Authorization header. Might be empty string.
  // * hostname     - Hostname of the target server
  // * port         - Port of the target server
  // * isHttp       - If true, this is a HTTP request, otherwise it's a HTTP CONNECT tunnel for SSL
  //                  or other protocols
  // * connectionId - Unique ID of the HTTP connection. It can be used to obtain traffic statistics.
  prepareRequestFunction: ({
    request,
    username,
    password,
    hostname,
    port,
    isHttp,
    connectionId
  }) => {
    return {
      // Sets up an upstream HTTP proxy to which all the requests are forwarded.
      // If null, the proxy works in direct mode, i.e. the connection is forwarded directly
      // to the target server. This field is ignored if "requestAuthentication" is true.
      // The username and password must be URI-encoded.
      upstreamProxyUrl: `http://username:[email protected]`,

      // If "requestAuthentication" is true, you can use the following property
      // to define a custom error message to return to the client instead of the default "Proxy credentials required"
      failMsg: "Bad username or password, please try again."
    }
  }
})

server.listen(() => {
  console.log(`Proxy server is listening on port ${server.port}`)
})

// Emitted when HTTP connection is closed
server.on("connectionClosed", ({ connectionId, stats }) => {
  console.log(`Connection ${connectionId} closed`)
  console.dir(stats)
})

// Emitted when HTTP request fails
server.on("requestFailed", ({ request, error }) => {
  console.log(`Request ${request.url} failed`)
  console.error(error)
})