Docker Hub 镜像代理

export default {
  async fetch(request) {
    const url = new URL(request.url)
    const workerHost = url.hostname
    const registry = 'registry-1.docker.io'
    const auth = 'https://auth.docker.io'

    // 转发 Docker Hub 令牌请求
    if (url.pathname === '/token') {
      const tokenUrl = auth + url.pathname + url.search

      return fetch(tokenUrl, {
        headers: request.headers,
      })
    }

    // 转发 Docker Hub Registry API 请求
    url.hostname = registry

    const headers = new Headers(request.headers)
    headers.set('Host', registry)

    const response = await fetch(url.toString(), {
      method: request.method,
      headers,
      body: request.method === 'GET' || request.method === 'HEAD' ? undefined : request.body,
    })

    const newHeaders = new Headers(response.headers)

    // 将认证地址改写为当前 Worker
    const www = newHeaders.get('Www-Authenticate')

    if (www) {
      newHeaders.set('Www-Authenticate', www.replace(auth, `https://${workerHost}`))
    }

    return new Response(response.body, {
      status: response.status,
      headers: newHeaders,
    })
  },
}