问题
今天遇到个问题，Mac m1 上拉取之前java构建的程序发现跑不起来，第一反应arm平台不兼容之前在x86架构下构建的镜像。 现如今云厂商好多服务器都是arm架构的，加上window11都支持arm架构了（Windows on ARM），arm以后会越来越频繁使用了。 这时就得祭出docker出的利器 buildx，可以一次构建多个平台的镜像。废话不多，开搞。。
buildx其实是个容器工具 moby/buildkit:buildx-stable-1
# Create a new builder
➜ ~ docker buildx create --name mybuilder --bootstrap --use
# 查看builder
➜ ~ docker buildx inspect mybuilder
Name: mybuilder
Driver: docker-container
Nodes:
Name: mybuilder0
Endpoint: unix:///var/run/docker.sock
Status: running
Buildkit: v0.11.2
Platforms: linux/arm64, linux/amd64, linux/amd64/v2, linux/riscv64, linux/ppc64le, linux/s390x, linux/386, linux/mips64le, linux/mips64, linux/arm/v7, linux/arm/v6
构建
# 一条命令搞定，会pudh到registry 区别于常规build
➜ ~ docker buildx build --platform linux/arm64/v8,linux/amd64 -t registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2 --push back
# 常规build 不push
➜ ~ docker build -t registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.1 back
查看registry构建成功
➜ ~ docker buildx imagetools inspect registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2
Name: registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2
MediaType: application/vnd.docker.distribution.manifest.list.v2+json
Digest: sha256:d1bce5ac3d722d5839417ba1524c6559db491569f900f20c8dd080f03e931bf9
Manifests:
Name: registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2@sha256:3e4d09f006d30c2644783a84abe99d22631930fb0a912bd291d4820d5eb328ac
MediaType: application/vnd.docker.distribution.manifest.v2+json
Platform: linux/arm64
Name: registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2@sha256:f1e39a33c800f3aab5b2e9de497871ae1a5b3e1b918b57bd9724d2b795e8b49f
MediaType: application/vnd.docker.distribution.manifest.v2+json
Platform: linux/amd64
客户端测试 会自动拉取自己平台的镜像
Apple M1 （ARM64）
➜ ~ docker pull registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2
0.2: Pulling from xiaoqioatq2/aa
0362ad1dd800: Already exists
571218f61883: Already exists
abe576d65b4c: Already exists
88e233291907: Pull complete
6f085c5d0e88: Pull complete
c740effa2ce7: Pull complete
Digest: sha256:d1bce5ac3d722d5839417ba1524c6559db491569f900f20c8dd080f03e931bf9
Status: Downloaded newer image for registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2
registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2
➜ ~ docker image inspect registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2 --format '{{.Os}}/{{.Architecture}}'
linux/arm64
Centos （AMD64）
[root@VM-4-3-centos ~]# docker pull registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2
0.2: Pulling from xiaoqioatq2/aa
e7c96db7181b: Already exists
f910a506b6cb: Already exists
c2274a1a0e27: Already exists
5023d05d0236: Pull complete
65e39c71f562: Pull complete
c740effa2ce7: Pull complete
Digest: sha256:d1bce5ac3d722d5839417ba1524c6559db491569f900f20c8dd080f03e931bf9
Status: Downloaded newer image for registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2
registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2
[root@VM-4-3-centos ~]# docker image inspect registry.cn-hangzhou.aliyuncs.com/xiaoqioatq2/aa:0.2 --format '{{.Os}}/{{.Architecture}}'
linux/amd64
发现的问题
镜像摘要混乱 docker cli 拉取镜像时digest是manifest总的摘要，不是各自平台的digest，也有人提了issue，期待早日解决。
Docker hub 只显示各个平台的digest，不显示总digest。
阿里云registry 只显示了amd64平台的digest 会误导。
多平台构建速度比较慢，后期考虑用github action来构建