Backblaze B2 + CloudFlare 搭建图床

Flinty Lemming
8 min readDec 15, 2020

Backblaze B2 在大厂的对象存储里算是非常便宜的了,如果不考虑国内访问速度,应该是非常不错的选择。由于 B2 与 CloudFlare 合作,所以套上 CloudFlare 后并不会消耗流量,所以拿来做图床是个不错的选择,下面介绍下步骤。

配置 CDN

以下步骤参考官方教程

Using Backblaze B2 with the Cloudflare CDN

1. 创建一个公开的存储桶并上传文件

2. 通过查看文件详细信息获得地址,比如我这里就是

https://f002.backblazeb2.com/file/<存储桶名称>/......

3. 在 CloudFlare 里新建一条 CNAME 解析,地址就填刚才获得的这个 f002.backblazeb2.com

4. 在 页面规则 里 创建页面规则

5. URL 匹配填写如下内容

https://<刚才解析的域名>/file/<存储桶>/*

添加设置中选择 缓存级别 — 缓存所有内容

6. 再添加一条

URL 匹配填写如下内容

https://<解析的域名>/file/*/*

设置填写 转发 URL — 302重定向 — https://secure.backblaze.com/404notfound

7. 设定缓存控制时间,内容如下

{“cache-control”:”max-age=720000"}

隐藏 Bucket 名称

这样设置完后,虽然能免流了,但是 Bucket 名称还是暴露了,为了避免被人搞事情,所以要隐藏 Bucket 名称。这里用到了 cf 的 workers,参考下面站点的内容。

Using Backblaze B2 and Cloudflare Workers for free image hosting

1. Workers — 管理 Workers

2. 添加一个 Worker 并部署,内容如下。你需要做的就是修改开头的 b2Domain 和 b2Bucket 两个变量即可。

'use strict';
const b2Domain = 'files.jross.me'; // configure this as per instructions above
const b2Bucket = 'jross-files'; // configure this as per instructions above
const b2UrlPath = `/file/${b2Bucket}/`;
addEventListener('fetch', event => {
return event.respondWith(fileReq(event));
});
// define the file extensions we wish to add basic access control headers to
const corsFileTypes = ['png', 'jpg', 'gif', 'jpeg', 'webp'];
// backblaze returns some additional headers that are useful for debugging, but unnecessary in production. We can remove these to save some size
const removeHeaders = [
'x-bz-content-sha1',
'x-bz-file-id',
'x-bz-file-name',
'x-bz-info-src_last_modified_millis',
'X-Bz-Upload-Timestamp',
'Expires'
];
const expiration = 31536000; // override browser cache for images - 1 year
// define a function we can re-use to fix headers
const fixHeaders = function(url, status, headers){
let newHdrs = new Headers(headers);
// add basic cors headers for images
if(corsFileTypes.includes(url.pathname.split('.').pop())){
newHdrs.set('Access-Control-Allow-Origin', '*');
}
// override browser cache for files when 200
if(status === 200){
newHdrs.set('Cache-Control', "public, max-age=" + expiration);
}else{
// only cache other things for 5 minutes
newHdrs.set('Cache-Control', 'public, max-age=300');
}
// set ETag for efficient caching where possible
const ETag = newHdrs.get('x-bz-content-sha1') || newHdrs.get('x-bz-info-src_last_modified_millis') || newHdrs.get('x-bz-file-id');
if(ETag){
newHdrs.set('ETag', ETag);
}
// remove unnecessary headers
removeHeaders.forEach(header => {
newHdrs.delete(header);
});
return newHdrs;
};
async function fileReq(event){
const cache = caches.default; // Cloudflare edge caching
const url = new URL(event.request.url);
if(url.host === b2Domain && !url.pathname.startsWith(b2UrlPath)){
url.pathname = b2UrlPath + url.pathname;
}
let response = await cache.match(url); // try to find match for this request in the edge cache
if(response){
// use cache found on Cloudflare edge. Set X-Worker-Cache header for helpful debug
let newHdrs = fixHeaders(url, response.status, response.headers);
newHdrs.set('X-Worker-Cache', "true");
return new Response(response.body, {
status: response.status,
statusText: response.statusText,
headers: newHdrs
});
}
// no cache, fetch image, apply Cloudflare lossless compression
response = await fetch(url, {cf: {polish: "lossless"}});
let newHdrs = fixHeaders(url, response.status, response.headers);
response = new Response(response.body, {
status: response.status,
statusText: response.statusText,
headers: newHdrs
});
event.waitUntil(cache.put(url, response.clone()));
return response;
}

3. 添加完后设置路由

4. 地址为

<解析的域名>/*

Worker 就选择刚才添加的 Worker

然后就可以直接通过 https://<域名>/<Bucket内路径> 引用文件了

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