使用 Cloudflare Workers 加速 Oracle Cloud 对象存储

2022-04-22 05:52:01

# 网络

Intro

Oracle Cloud 是由甲骨文驱动的公有云产品，其 Free Tier 计划包含了 20GB 的对象存储服务。由于其可用区位于海外，跨境访问对象存储时用户体验很不理想。我们可以使用 Cloudflare Workers 搭建反向代理，并配合缓存以节省开销。

Passthrough

直通模式下，Cloudflare Workers 直接转发请求和响应。

const REGION = "";
const BUCKET = "";
const NAMESPACE = "";

const BUCKET_URL = `https://objectstorage.${REGION}.oraclecloud.com/n/${NAMESPACE}/b/${BUCKET}/o`;

addEventListener("fetch", (event) => {
  event.respondWith(handle(event));
});

async function handle(event) {
  const pathname = new URL(event.request.url).pathname;
  return fetch(`${BUCKET_URL}${pathname}`);
}

Cache

缓存模式下，先使用 Cache API 将请求缓存于 Cloudflare 的 CDN ，再返回响应正文。

const REGION = "";
const BUCKET = "";
const NAMESPACE = "";

const BUCKET_URL = `https://objectstorage.${REGION}.oraclecloud.com/n/${NAMESPACE}/b/${BUCKET}/o`;

addEventListener("fetch", (event) => {
  event.respondWith(handle(event));
});

async function handle(event) {
  let request = event.request;

if (["GET", "HEAD", "OPTIONS"].includes(request.method)) {
    const pathname = new URL(request.url).pathname;
    const cache = caches.default;

let response;
    if (request.method === "GET") {
      // 缓存 GET 请求
      response = await cache.match(request);
      if (!response) {
        response = await fetch(`${BUCKET_URL}${pathname}`);
        let headers = Object.fromEntries(new Map(response.headers));
        headers["cache-control"] = "public, max-age=14400";
        response = new Response(response.body, { ...response, headers });
        event.waitUntil(cache.put(request, response.clone()));
      }
    } else {
      // 将非 GET 请求直接转发
      response = fetch(`${BUCKET_URL}${pathname}`, { method: request.method });
    }

// override 错误信息以避免泄露 bucket 名称
    if (response.status === 404)
      return new Response("Not found", { status: 404 });

// 允许浏览器直接播放 .mp4 文件而不触发下载
    if (pathname.endsWith(".mp4")) {
      headers = { "Content-Type": "video/mp4" };
      response = new Response(response.body, { ...response.body, headers });
    }
    return response;
  } else {
    return new Response("Method not allowed", { status: 405 });
  }
}

• Before: 从境内直连对象存储，下载速度约为 50KB/s。
• After: 在未使用自选 Cloudflare IP 的前提下，下载速度可达 6MB/s，提升 60~120x。

• Configure your CDN - Cloudflare Workers docs