Github反向代理

引子

因为墙的存在, github访问,下载源代码,体验一直不是很友好.使用cloudflare的workers来搭建无服务器版本的反向代理,来解决此问题.

源代码仓库

准备工作

  • cloudflare 账号
  • 一个域名(可选,建议)

过程

  1. 登录cloudflare账号, 新建workers,部署
  2. 编辑代码,填入官方仓库的`index.js`文件的内容
    'use strict'
    
    /**
     * static files (404.html, sw.js, conf.js)
     */
    const ASSET_URL = 'https://hunshcn.github.io/gh-proxy/'
    // 前缀,如果自定义路由为example.com/gh/*,将PREFIX改为 '/gh/',注意,少一个杠都会错!
    const PREFIX = '/'
    // 分支文件使用jsDelivr镜像的开关,0为关闭,默认关闭
    const Config = {
        jsdelivr: 0
    }
    
    const whiteList = [] // 白名单,路径里面有包含字符的才会通过,e.g. ['/username/']
    
    /** @type {RequestInit} */
    const PREFLIGHT_INIT = {
        status: 204,
        headers: new Headers({
            'access-control-allow-origin': '*',
            'access-control-allow-methods': 'GET,POST,PUT,PATCH,TRACE,DELETE,HEAD,OPTIONS',
            'access-control-max-age': '1728000',
        }),
    }
    
    
    const exp1 = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:releases|archive)\/.*$/i
    const exp2 = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:blob|raw)\/.*$/i
    const exp3 = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:info|git-).*$/i
    const exp4 = /^(?:https?:\/\/)?raw\.(?:githubusercontent|github)\.com\/.+?\/.+?\/.+?\/.+$/i
    const exp5 = /^(?:https?:\/\/)?gist\.(?:githubusercontent|github)\.com\/.+?\/.+?\/.+$/i
    const exp6 = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/tags.*$/i
    
    /**
     * @param {any} body
     * @param {number} status
     * @param {Object<string, string>} headers
     */
    function makeRes(body, status = 200, headers = {}) {
        headers['access-control-allow-origin'] = '*'
        return new Response(body, {status, headers})
    }
    
    
    /**
     * @param {string} urlStr
     */
    function newUrl(urlStr) {
        try {
            return new URL(urlStr)
        } catch (err) {
            return null
        }
    }
    
    
    addEventListener('fetch', e => {
        const ret = fetchHandler(e)
            .catch(err => makeRes('cfworker error:\n' + err.stack, 502))
        e.respondWith(ret)
    })
    
    
    function checkUrl(u) {
        for (let i of [exp1, exp2, exp3, exp4, exp5, exp6]) {
            if (u.search(i) === 0) {
                return true
            }
        }
        return false
    }
    
    /**
     * @param {FetchEvent} e
     */
    async function fetchHandler(e) {
        const req = e.request
        const urlStr = req.url
        const urlObj = new URL(urlStr)
        let path = urlObj.searchParams.get('q')
        if (path) {
            return Response.redirect('https://' + urlObj.host + PREFIX + path, 301)
        }
        // cfworker 会把路径中的 `//` 合并成 `/`
        path = urlObj.href.substr(urlObj.origin.length + PREFIX.length).replace(/^https?:\/+/, 'https://')
        if (path.search(exp1) === 0 || path.search(exp5) === 0 || path.search(exp6) === 0 || path.search(exp3) === 0 || path.search(exp4) === 0) {
            return httpHandler(req, path)
        } else if (path.search(exp2) === 0) {
            if (Config.jsdelivr) {
                const newUrl = path.replace('/blob/', '@').replace(/^(?:https?:\/\/)?github\.com/, 'https://cdn.jsdelivr.net/gh')
                return Response.redirect(newUrl, 302)
            } else {
                path = path.replace('/blob/', '/raw/')
                return httpHandler(req, path)
            }
        } else if (path.search(exp4) === 0) {
            const newUrl = path.replace(/(?<=com\/.+?\/.+?)\/(.+?\/)/, '@$1').replace(/^(?:https?:\/\/)?raw\.(?:githubusercontent|github)\.com/, 'https://cdn.jsdelivr.net/gh')
            return Response.redirect(newUrl, 302)
        } else {
            return fetch(ASSET_URL + path)
        }
    }
    
    
    /**
     * @param {Request} req
     * @param {string} pathname
     */
    function httpHandler(req, pathname) {
        const reqHdrRaw = req.headers
    
        // preflight
        if (req.method === 'OPTIONS' &&
            reqHdrRaw.has('access-control-request-headers')
        ) {
            return new Response(null, PREFLIGHT_INIT)
        }
    
        const reqHdrNew = new Headers(reqHdrRaw)
    
        let urlStr = pathname
        let flag = !Boolean(whiteList.length)
        for (let i of whiteList) {
            if (urlStr.includes(i)) {
                flag = true
                break
            }
        }
        if (!flag) {
            return new Response("blocked", {status: 403})
        }
        if (urlStr.startsWith('github')) {
            urlStr = 'https://' + urlStr
        }
        const urlObj = newUrl(urlStr)
    
        /** @type {RequestInit} */
        const reqInit = {
            method: req.method,
            headers: reqHdrNew,
            redirect: 'manual',
            body: req.body
        }
        return proxy(urlObj, reqInit)
    }
    
    
    /**
     *
     * @param {URL} urlObj
     * @param {RequestInit} reqInit
     */
    async function proxy(urlObj, reqInit) {
        const res = await fetch(urlObj.href, reqInit)
        const resHdrOld = res.headers
        const resHdrNew = new Headers(resHdrOld)
    
        const status = res.status
    
        if (resHdrNew.has('location')) {
            let _location = resHdrNew.get('location')
            if (checkUrl(_location))
                resHdrNew.set('location', PREFIX + _location)
            else {
                reqInit.redirect = 'follow'
                return proxy(newUrl(_location), reqInit)
            }
        }
        resHdrNew.set('access-control-expose-headers', '*')
        resHdrNew.set('access-control-allow-origin', '*')
    
        resHdrNew.delete('content-security-policy')
        resHdrNew.delete('content-security-policy-report-only')
        resHdrNew.delete('clear-site-data')
    
        return new Response(res.body, {
            status,
            headers: resHdrNew,
        })
    }
  3. 部署即可
  4. 绑定自定义的一个域名,可以是二级域名(可选),主要是默认的域名不好记住

使用

以后在github链接前缀加上 自定义的域名即可下载或者拉取仓库

比如克隆仓库的时候添加前缀,即可实现代理

Github反代地址

阅读剩余
THE END