WirelessLink

自建Gravatar代理服务的方法

Cloudflare Workers的名称来自Web Workers，更具体地说是Service Workers，一个用于在web浏览器后台运行并拦截HTTP请求的脚本的W3C标准API。Cloudflare Workers是针对相同的标准API编写的，但是是在Cloudflare的服务器上运行，而不是在浏览器中运行。

Cloudflare Workers免费套餐：每天100,000请求

Cloudflare Workers特点：

使用最新的标准语言功能执行任意JavaScript代码。
拦截和修改HTTP请求和响应URL，状态，标头和正文内容。
直接从您的Worker响应请求，或将其转发到其他地方。
将HTTP请求发送到第三方服务器。
以串行或并行方式发送多个请求，并使用响应组成对原始请求的最终响应。
在响应已经返回到客户端之后发送异步请求（例如，用于记录或分析）。
控制其他Cloudflare功能，例如缓存行为。

创建了Workers后，直接把代码复制即可。

代码如下：

https://github.com/lingchenzi/blog/blob/main/cloudflare-workers-gravatar

// 替换成你想镜像的站点
const upstream = gravatar.com’

// 如果那个站点有专门的移动适配站点，否则保持和上面一致
const upstream_mobile = ‘gravatar.com’

// 你希望禁止哪些国家访问
const blocked_region = []

// 禁止自访问
const blocked_ip_address = [‘0.0.0.0’, ‘127.0.0.1’]

// 替换成你想镜像的站点
const replace_dict = {
‘$upstream’: ‘$custom_domain’,
‘//gravatar.com: ”
}

//以下内容都不用动
addEventListener(‘fetch’, event => {
event.respondWith(fetchAndApply(event.request));
})

async function fetchAndApply(request) {

const region = request.headers.get(‘cf-ipcountry’).toUpperCase();
const ip_address = request.headers.get(‘cf-connecting-ip’);
const user_agent = request.headers.get(‘user-agent’);

let response = null;
let url = new URL(request.url);
let url_host = url.host;

if (url.protocol == ‘http:’) {
url.protocol = ‘https:’
response = Response.redirect(url.href);
return response;
}

if (await device_status(user_agent)) {
upstream_domain = upstream
} else {
upstream_domain = upstream_mobile
}

url.host = upstream_domain;

if (blocked_region.includes(region)) {
response = new Response(‘Access denied: WorkersProxy is not available in your region yet.’, {
status: 403
});
} else if(blocked_ip_address.includes(ip_address)){
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);
new_request_headers.set(‘Referer’, url.href);

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;

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.includes(‘text/html’) && content_type.includes(‘UTF-8’)) {
original_text = await replace_response_text(original_response_clone, upstream_domain, url_host);
} 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()

var i, j;
for (i in replace_dict) {
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);
}
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;
}
你可以重命名创建的Workers为gravata，也可以将自定义域名绑定到Workers上面，下一篇再讲如何绑定自定义域名到CloudFlare Workers。