====== Pleroma 使用 Cloudflare Worker 搭建代理 ======

如果没有 Cloudflare 账户的话，可以到 [[https://dash.cloudflare.com/login|dash.cloudflare.com]] 注册账户，套餐全部选择 Free 即可。

===== 创建 Worker =====

进入 [[https://dash.cloudflare.com/|Cloudflare 管理界面]] ，您会看到：
{{ ::cloudflare:cf-panel.png?nolink | Cloudflare Panel}}
点击右下角的这个 Worker 按钮进入 Worker 面板：
{{ :cloudflare:cf-worker-icon.png?nolink |}}
点击 Create a Worker，创建 Worker。
{{ :cloudflare:cf-create-worker.png?nolink |Create Worker}}
此时，如果您点击 Save and Deploy 按钮，您会看到您的代理的域名，您需要记下这个域名。（当然记不得的话，您也可以在很多其它地方重新找到这个域名。）
确认后，您可以点击 Send 按钮，您会看到 200 OK 的响应。

===== 更改 Worker 代码 =====

将左侧的代码编辑窗口的代码全部删除干净，粘贴入下面的代码：
<code>
// 你要镜像的网站.
const upstream = 'pleroma.example.com'

const upstream_path = '/'
const upstream_mobile = upstream
const blocked_region = ['KP', 'SY', 'PK', 'CU']
const blocked_ip_address = ['0.0.0.0', '127.0.0.1']
const https = true
const replace_dict = {
    '$upstream': '$custom_domain',
}

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_hostname = url.hostname;

    if (https == true) {
        url.protocol = 'https:';
    } else {
        url.protocol = 'http:';
    }

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

    url.host = upstream_domain;
    if (url.pathname == '/') {
        url.pathname = upstream_path;
    } else {
        url.pathname = upstream_path + url.pathname;
    }

    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', url.hostname);
        new_request_headers.set('Referer', url.hostname);

        let request_body = null;
        if(url.href.includes('/api/v1/media')) {
            request_body = request.body
        } else if(method === 'POST' || method === 'PATCH' || method === 'PUT') {
            request_body = '';
            request_body = await request.text();
            if(request_body) {
                let re = new RegExp(url_hostname, 'g')
                request_body = request_body.replace(re, upstream);
            }
        }

        let original_response = await fetch(url.href, {
            method: method,
            headers: new_request_headers,
            body: request_body
        })

        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_hostname);
        } 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;
}
</code>
代码改自 https://umrhe.com/cloudflare-workers-to-google.html 。
粘贴完后，把”你要镜像的网站“处的 ''const upstream = 'pleroma.example.com' '' 改成 <code>const upstream = '您的Pleroma域名'</code>
改完后点击 Save and Deploy 即可。此时您访问代理域名就可以正常使用 Pleroma 了。

如果认为域名太长太难记，您也可以查询另外绑定域名的教程，此处不详述。

==== 安全提醒 ====

  安全提醒
  反代这种事情是谁都可以做的，并不需要官方的授权。所以很可能被人用于钓鱼攻击。
  使用替代域名登录实例之前，请一定要确认这个替代域名是官方建立的。

引自 [[https://blog.bgme.me/posts/nginx-reverser-proxy-for-mastodon/#id3|影子屋]]