Node.js proxy mitm log example

proxy_mitm_example.js

// run: mitmproxy -p 8080
// run: node proxy.js

async function setupProxy (proxyUrl) {
  // require('global-agent/bootstrap')
  // process.env.GLOBAL_AGENT_HTTP_PROXY = proxyUrl
  // process.env.GLOBAL_AGENT_HTTPS_PROXY = proxyUrl
  // console.log('Global proxy routing set up.')

  process.env.NODE_TLS_REJECT_UNAUTHORIZED = '0' // Ignore self-signed certs, use with caution

  const { HttpsProxyAgent } = require('https-proxy-agent')

  // Set up the proxy agent for https module
  const https = require('https')
  const url = require('url')

  class LoggingProxyAgentForHttpsModule extends HttpsProxyAgent {
    constructor(proxyOptions) {
      super(proxyOptions)
    }

    // Override the addRequest method to log URLs
    addRequest(req, options) {
      // Log the full URL or just the pathname, depending on your needs
      if (typeof options === 'string') {
        options = url.parse(options)
      }
      const fullUrl = url.format({
        protocol: options.protocol,
        hostname: options.hostname,
        port: options.port,
        pathname: options.path
      })
      console.log('Request URL (https):', fullUrl)

      // Call the original addRequest method
      super.addRequest(req, options)
    }
  }

  const originalFetch = global.fetch // Save the original fetch function
  const { ProxyAgent } = require('undici')

  class LoggingProxyAgentForFetchModule extends ProxyAgent {
    constructor(uri, options) {
      super(uri, options)
    }

    dispatch(options, handler) {
      console.log('Request URL (fetch):', options.origin + options.path)

      return super.dispatch(options, handler)
    }
  }

  // Use your custom agent
  const proxyAgentForHttpsModule = new LoggingProxyAgentForHttpsModule(proxyUrl)
  const proxyAgentForFetchModule = new LoggingProxyAgentForFetchModule(proxyUrl)

  // Override global https agent
  https.globalAgent = proxyAgentForHttpsModule

  // Override global fetch
  global.fetch = (url, options = {}) => {
    options.dispatcher = proxyAgentForFetchModule
    return originalFetch(url, options)
  }
}

async function main () {
  setupProxy('http://localhost:8080')

  // Example curl request
  // curl -x http://localhost:8080 -L http://example.com

  // Example requests
  await require('axios').get('https://example.com/') // Request URL (https): https://example.com:443/
  await require('node-fetch')('https://example.com/') // Request URL (https): https://example.com:443/
  await require('isomorphic-fetch')('https://example.com/') // Request URL (https): https://example.com:443/
  await fetch('https://example.com/') // Request URL (fetch): https://example.com/

  console.log('done')
}

main().catch(console.error)