Docker在未缓存的镜像上使用buildkit和mirror.gcr.io构建失败

Question

当构建引用未缓存在mirror.gcr.io上的镜像的cached文件时，当使用DOCKER_BUILDKIT=1启用时，构建失败：

$ cat Dockerfile.test
FROM debian:10

$ sudo cat /etc/docker/daemon.json
{
        "registry-mirrors": ["https://mirror.gcr.io"]
}

$ DOCKER_BUILDKIT=1 docker build -f Dockerfile.test . 
[+] Building 1.0s (4/4) FINISHED                                                                                                                                                                                
 => [internal] load .dockerignore                                                                                                                                                                          0.0s
 => => transferring context: 2B                                                                                                                                                                            0.0s
 => [internal] load build definition from Dockerfile.test                                                                                                                                                  0.0s
 => => transferring dockerfile: 42B                                                                                                                                                                        0.0s
 => ERROR [internal] load metadata for docker.io/library/debian:10                                                                                                                                         0.6s
 => ERROR [1/1] FROM docker.io/library/debian:10                                                                                                                                                           0.3s
 => => resolve docker.io/library/debian:10                                                                                                                                                                 0.3s
------
 > [internal] load metadata for docker.io/library/debian:10:
------
------
 > [1/1] FROM docker.io/library/debian:10:
------
failed to solve with frontend dockerfile.v0: failed to build LLB: failed to load cache key: docker.io/library/debian:10 not found

Answer 1

最新的(稳定的) docker没有最新的buildkit。如果在镜像上找不到镜像，Buildkit 0.7实际上会故障转移到正常的docker Hub。

作为Github上@tonistiigi的per instruction：使用docker20.10(目前是测试版)，或者使用带有较新构建工具包的docker buildx。