public-image-mirror

Pulling container images from Google's registry or GitHub from inside China is slow to the point of useless. public-image-mirror fixes that. It's a free public mirror, run by DaoCloud, that caches images from gcr.io, ghcr.io, Docker Hub and others on fast domestic servers. (A container image is the packaged-up bundle your app and its dependencies ship in.) You change one thing: put m.daocloud.io/ in front of the image name, and the pull comes from China instead of crawling across the Pacific.

There is nothing to run. No container to maintain, no server to stand up. You edit your image references, or point your Kubernetes, containerd, or Ollama config at the mirror, and you are done. That also means there is nothing you control. It is somebody else's infrastructure, free of charge, with the limits that implies: images are cached for 30 days, peak hours get congested, and the maintainers flat-out recommend scheduling big pulls for 1 to 7 AM Beijing time.

If you are building from behind the Great Firewall, this is close to essential and costs nothing. Solo or enterprise, the call is the same: use it. If you are outside China with normal access to the upstream registries, you do not need it, and you probably do not want a third-party mirror in your supply chain when the real thing is already fast.

The catch is trust. Every image you pull through a mirror is an image you are trusting the mirror to serve unchanged. DaoCloud keeps hash consistency with the source, which is the right call, but you are still routing your supply chain through someone else's servers. Fine for dev and CI pulls. Think harder before you bake it into a production base image.