利用Cloudfare worker反代github

1. 绑定你的域名到 cloudflare

2. 创建一个 worker，并写入如下代码：

   // 反代目标网站.
   const upstream = 'github.com';
   
   // 反代目标网站的移动版.
   const upstream_mobile = 'github.com';
   
   // 访问区域黑名单（按需设置）.
   const blocked_region = [''];
   
   // IP地址黑名单（按需设置）.
   const blocked_ip_address = ['0.0.0.0', '127.0.0.1'];
   
   // 路径替换.
   const replace_dict = {
     '$upstream': '$custom_domain', // 将"$upstream"替换为"$custom_domain"
     '//github.com': '' // 移除路径中的"//github.com"
   };
   
   addEventListener('fetch', event => {
     event.respondWith(fetchAndApply(event.request));
   });
   
   async function fetchAndApply(request) {
     const region = request.headers.get('cf-ipcountry').toUpperCase(); // 获取访问者所在的地区
     const ip_address = request.headers.get('cf-connecting-ip'); // 获取访问者的IP地址
     const user_agent = request.headers.get('user-agent'); // 获取访问者的User-Agent头部信息
   
     let response = null;
     let url = new URL(request.url);
     let url_host = url.host;
   
     if (url.protocol == 'http:') { // 如果请求协议是HTTP，则重定向到HTTPS
       url.protocol = 'https:';
       response = Response.redirect(url.href);
       return response;
     }
   
     if (await device_status(user_agent)) { // 判断是否为移动设备
       var upstream_domain = upstream;
     } else {
       var upstream_domain = upstream_mobile;
     }
   
     url.host = upstream_domain;
   
     if (blocked_region.includes(region)) { // 检查访问区域是否在黑名单中
       response = new Response('Access denied: WorkersProxy is not available in your region yet.', {
         status: 403
       });
     } else if (blocked_ip_address.includes(ip_address)){ // 检查IP地址是否在黑名单中
       response = new Response('Access denied: Your IP address is blocked by WorkersProxy.', {
         status: 403
       });
     } else {
       let method = request.method;
       let request_headers = request.headers;
       let new_request_headers = new Headers(request_headers);
   
       new_request_headers.set('Host', upstream_domain); // 设置请求头的Host字段为反代目标网站的域名
       new_request_headers.set('Referer', url.href); // 设置请求头的Referer字段为当前请求的URL
   
       let original_response = await fetch(url.href, {
         method: method,
         headers: new_request_headers
       });
   
       let original_response_clone = original_response.clone();
       let original_text = null;
       let response_headers = original_response.headers;
       let new_response_headers = new Headers(response_headers);
       let status = original_response.status;
   
       // 修改响应头的设置
       new_response_headers.set('cache-control', 'public, max-age=14400');
       new_response_headers.set('access-control-allow-origin', '*');
       new_response_headers.set('access-control-allow-credentials', true);
       new_response_headers.delete('content-security-policy');
       new_response_headers.delete('content-security-policy-report-only');
       new_response_headers.delete('clear-site-data');
   
       const content_type = new_response_headers.get('content-type');
       if (content_type && content_type.includes('text/html') && content_type.includes('UTF-8')) {
         original_text = await replace_response_text(original_response_clone, upstream_domain, url_host); // 替换响应中的文本内容
       } else {
         original_text = original_response_clone.body;
       }
   
       response = new Response(original_text, {
         status,
         headers: new_response_headers
       });
     }
     return response;
   }
   
   async function replace_response_text(response, upstream_domain, host_name) {
     let text = await response.text();
   
     for (let i in replace_dict) {
       let j = replace_dict[i];
       if (i == '$upstream') {
         i = upstream_domain;
       } else if (i == '$custom_domain') {
         i = host_name;
       }
   
       if (j == '$upstream') {
         j = upstream_domain;
       } else if (j == '$custom_domain') {
         j = host_name;
       }
   
       let re = new RegExp(i, 'g');
       text = text.replace(re, j); // 使用正则表达式替换文本内容
     }
   
     return text;
   }
   
   async function device_status(user_agent_info) {
     var agents = ["Android", "iPhone", "SymbianOS", "Windows Phone", "iPad", "iPod"];
     var flag = true;
     for (var v = 0; v < agents.length; v++) {
       if (user_agent_info.indexOf(agents[v]) > 0) {
         flag = false;
         break;
       }
     }
     return flag;
   }

3. 自定义域名，方便访问