What is public-image-mirror?

This repository provides a public mirror service for container images that are slow or inaccessible from within China. Container images are packages used to run software in isolated environments called containers, and many popular image registries such as Google gcr.io, GitHub ghcr.io, Microsoft mcr.microsoft.com, and registry.k8s.io are hosted outside China, making downloads slow or unreliable for users and servers inside the country. The mirror works by adding a prefix to any image URL. Instead of pulling from docker.io/library/nginx, you pull from m.daocloud.io/docker.io/library/nginx. An alternative is to swap the registry domain for a DaoCloud equivalent: docker.io becomes docker.m.daocloud.io, gcr.io becomes gcr.m.daocloud.io, registry.k8s.io becomes k8s.m.daocloud.io, and so on for all supported registries. The README includes a table listing each supported source registry and its mirror address. Configuration examples are provided for Docker, Kubernetes (via kubeadm and kind), and Containerd. For Kubernetes clusters, there is also a Webhook-based tool that automatically rewrites image references in all new pods without requiring any changes to existing YAML files or Helm charts. Ollama images and AI models such as DeepSeek-R1 can also be pulled through a dedicated mirror endpoint. Cached content is stored for 90 days and content hashes match the originals, so the files you receive are identical to what you would get from the source registries. The README notes that pulling is best done during off-peak hours (01:00 to 07:00 Beijing time) due to high demand during the day. The README is primarily written in Chinese, and the backend source code is maintained in a separate linked repository.