assetPrefix

注意力：部署到 Vercel 会自动为你的 Next.js 项目配置全局 CDN。你无需手动设置资源前缀。

¥Attention: Deploying to Vercel automatically configures a global CDN for your Next.js project. You do not need to manually setup an Asset Prefix.

很高兴知道：Next.js 9.5+ 添加了对可自定义基本路径的支持，它更适合在 /docs 这样的子路径上托管应用。我们不建议你为此用例使用自定义资源前缀。

¥Good to know: Next.js 9.5+ added support for a customizable Base Path, which is better suited for hosting your application on a sub-path like /docs. We do not suggest you use a custom Asset Prefix for this use case.

设置 CDN

¥Set up a CDN

要设置 CDN，你可以设置资源前缀并配置 CDN 的来源以解析为托管 Next.js 的域。

¥To set up a CDN, you can set up an asset prefix and configure your CDN's origin to resolve to the domain that Next.js is hosted on.

打开 next.config.mjs 并根据 phase 添加 assetPrefix 配置：

¥Open next.config.mjs and add the assetPrefix config based on the phase:

// @ts-check
import { PHASE_DEVELOPMENT_SERVER } from 'next/constants'

export default (phase) => {
  const isDev = phase === PHASE_DEVELOPMENT_SERVER
  /**

   * @type {import('next').NextConfig}
   */
  const nextConfig = {
    assetPrefix: isDev ? undefined : 'https://cdn.mydomain.com',
  }
  return nextConfig
}

Next.js 将自动使用你从 /_next/ 路径（.next/static/ 文件夹）加载的 JavaScript 和 CSS 文件的资源前缀。例如，使用上述配置，对 JS 块的请求如下：

¥Next.js will automatically use your asset prefix for the JavaScript and CSS files it loads from the /_next/ path (.next/static/ folder). For example, with the above configuration, the following request for a JS chunk:

/_next/static/chunks/4b9b41aaa062cbbfeff4add70f256968c51ece5d.4d708494b3aed70c04f0.js

相反会变成：

¥Would instead become:

https://cdn.mydomain.com/_next/static/chunks/4b9b41aaa062cbbfeff4add70f256968c51ece5d.4d708494b3aed70c04f0.js

将文件上传到给定 CDN 的确切配置取决于你选择的 CDN。你需要在 CDN 上托管的唯一文件夹是 .next/static/ 的内容，应将其上传为 _next/static/，如上述 URL 请求所示。不要上传 .next/ 文件夹的其余部分，因为你不应该向公众公开你的服务器代码和其他配置。

¥The exact configuration for uploading your files to a given CDN will depend on your CDN of choice. The only folder you need to host on your CDN is the contents of .next/static/, which should be uploaded as _next/static/ as the above URL request indicates. Do not upload the rest of your .next/ folder, as you should not expose your server code and other configuration to the public.

虽然 assetPrefix 覆盖了对 _next/static 的请求，但它不影响以下路径：

¥While assetPrefix covers requests to _next/static, it does not influence the following paths:

public 文件夹中的文件；如果你想通过 CDN 提供这些资源，你必须自己引入前缀

¥Files in the public folder; if you want to serve those assets over a CDN, you'll have to introduce the prefix yourself

设置 CDN​

设置 CDN