Docker容器内Next.js应用抛出UND_ERR_CONNECT_TIMEOUT错误的排查求助

大家好，几个小时前我部署在Docker容器里的Next.js应用突然没法正常运行了。我用docker logs命令查看容器日志后，发现了下面的超时错误：

⨯ TypeError: fetch failed
    at node:internal/deps/undici/undici:12618:11
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async fetchExternalImage (/app/node_modules/next/dist/server/image-optimizer.js:565:17)
    at async NextNodeServer.imageOptimizer (/app/node_modules/next/dist/server/next-server.js:650:48)
    at async cacheEntry.imageResponseCache.get.incrementalCache (/app/node_modules/next/dist/server/next-server.js:182:65)
    at async /app/node_modules/next/dist/server/response-cache/index.js:90:36
    at async /app/node_modules/next/dist/lib/batcher.js:45:32 {
  cause: ConnectTimeoutError: Connect Timeout Error
      at onConnectTimeout (node:internal/deps/undici/undici:7760:28)
      at node:internal/deps/undici/undici:7716:50
      at Immediate._onImmediate (node:internal/deps/...

从错误栈能看出来，问题出在Next.js的图片优化器尝试抓取外部图片时连接超时了。我已经检查过外部图片源的可用性，在容器外是可以正常访问的，而且之前应用一直运行得很稳定，近期也没改过相关配置。

想请教下有没有朋友遇到过类似的问题？可能的排查方向有哪些？比如Docker容器的网络配置、Next.js的图片优化缓存设置，或者是Undici客户端的超时参数问题？

备注：内容来源于stack exchange，提问作者Elvin Hüseynov