proxy.js

// Cloudflare supports the GET, POST, HEAD, and OPTIONS methods from any origin,
// and allow any header on requests. These headers must be present
// on all responses to all CORS preflight requests. In practice, this means
// all responses to OPTIONS requests.

const allowOrigin = 'https://eidos.space';

const corsHeaders = {
  'Access-Control-Allow-Origin': allowOrigin,
  'Access-Control-Allow-Methods': 'GET,HEAD,POST,OPTIONS',
  'Access-Control-Max-Age': '86400',
};


async function handleRequest(request) {
  let url = new URL(request.url);
  const proxyURL = url.searchParams.get("url")
  if (!proxyURL){
    return new Response("no url")
  }
    
  // Rewrite request to point to API URL. This also makes the request mutable
  // so you can add the correct Origin header to make the API server think
  // that this request is not cross-site.
  console.log(proxyURL)
  let response = await fetch(proxyURL);
  console.log(response.statusText)

  // Recreate the response so you can modify the headers
  response = new Response(response.body, response);

  // Set CORS headers
  response.headers.set('Access-Control-Allow-Origin', allowOrigin);
  response.headers.set('Cross-Origin-Resource-Policy', "cross-origin");


  // Append to/Add Vary header so browser will cache response correctly
  response.headers.append('Vary', 'Origin');

  return response
}

function handleOptions(request) {
  // Make sure the necessary headers are present
  // for this to be a valid pre-flight request
  let headers = request.headers;
  if (
    headers.get('Origin') !== null &&
    headers.get('Access-Control-Request-Method') !== null &&
    headers.get('Access-Control-Request-Headers') !== null
  ) {
    // Handle CORS pre-flight request.
    // If you want to check or reject the requested method + headers
    // you can do that here.
    let respHeaders = {
      ...corsHeaders,
      // Allow all future content Request headers to go back to browser
      // such as Authorization (Bearer) or X-Client-Name-Version
      'Access-Control-Allow-Headers': request.headers.get('Access-Control-Request-Headers'),
    };

    return new Response(null, {
      headers: respHeaders,
    });
  } else {
    // Handle standard OPTIONS request.
    // If you want to allow other HTTP Methods, you can do that here.
    return new Response(null, {
      headers: {
        Allow: 'GET, HEAD, POST, OPTIONS',
      },
    });
  }
}

addEventListener('fetch', event => {
  const request = event.request;
  if (request.method === 'OPTIONS') {
    // Handle CORS preflight requests
    event.respondWith(handleOptions(request));
  } else if (request.method === 'GET' || request.method === 'HEAD' || request.method === 'POST') {
    // Handle requests to the API server
    event.respondWith(handleRequest(request));
  } else {
    event.respondWith(
      new Response(null, {
        status: 405,
        statusText: 'Method Not Allowed',
      })
    );
  }
});