前言
最近甲骨文首尔 ARM 免费服务器大量放货，我也开了一台 4C 24GB 的机器。这么大内存的机器，我想要在上面托管一些项目，由于一些项目的 Docker 镜像未提供 ARM 架构的支持，所以我了解了一下使用 Docker Buildx 来构建支持多架构的 Docker 镜像。
Docker Buildx 是 Docker CLI 的一个插件，它是默认 Docker Build 命令的拓展，完全支持 Moby BuildKit 构建器的特性并提供与 Docker Build 一致的体验，它带来的新特性之一就是支持构建多架构镜像，更多信息可以查看 Docker 文档 - Docker Buildx。
在构建机器上构建与本机 CPU 架构不同的 Docker 镜像会用到 QEMU 的用户空间 (userspace) 仿真和虚拟化，由于虚拟化和模拟有一定性能损失，所以整个构建过程会花费更多时间。
本文不讨论 Dockerfile 的写法，我们以 book-searcher 项目为例，在甲骨文 ARM 服务器 1 上构建支持 AMD64, ARM/V7, ARM64 的 Docker 镜像并推送到 Docker Hub
uname -a
Linux instance-oracle-arm 5.10.0-20-arm64 #1 SMP Debian 5.10.158-2 (2022-12-13) aarch64 GNU/Linux
准备
Docker Buildx 在 Docker 19.03 以上版本默认支持，在开始前，建议将构建机器上的 Docker 升级到最新版本
# 查看 buildx 版本信息
sudo docker buildx version
github.com/docker/buildx v0.10.0-docker 876462897612d36679153c3414f7689626251501
# 命令帮助
sudo docker buildx
Usage: docker buildx [OPTIONS] COMMAND
Extended build capabilities with BuildKit
Options:
--builder string Override the configured builder instance
Management Commands:
imagetools Commands to work on images in registry
Commands:
bake Build from a file
build Start a build
create Create a new builder instance
du Disk usage
inspect Inspect current builder instance
ls List builder instances
prune Remove build cache
rm Remove a builder instance
stop Stop builder instance
use Set the current builder instance
version Show buildx version information
Run 'docker buildx COMMAND --help' for more information on a command.
tonistiigi/binfmt 是一使用 Docker 镜像分发的跨平台仿真模拟器集合，在 Windows/macOS 上的 Docker Desktop 一般默认已经安装了
# 安装所有 CPU 架构模拟器
sudo docker run --privileged --rm tonistiigi/binfmt --install all
# 安装指定 CPU 架构模拟器
sudo docker run --privileged --rm tonistiigi/binfmt --install arm64,riscv64,arm
在 Linux 机器上安装
sudo docker run --privileged --rm tonistiigi/binfmt --install all
Unable to find image 'tonistiigi/binfmt:latest' locally
latest: Pulling from tonistiigi/binfmt
6dda554f4baf: Pull complete
2b0720d7a501: Pull complete
Digest: sha256:66e11bea77a5ea9d6f0fe79b57cd2b189b5d15b93a2bdb925be22949232e4e55
Status: Downloaded newer image for tonistiigi/binfmt:latest
{
"supported": [
"linux/arm64",
"linux/amd64",
"linux/riscv64",
"linux/ppc64le",
"linux/s390x",
"linux/386",
"linux/mips64le",
"linux/mips64",
"linux/arm/v7",
"linux/arm/v6"
],
"emulators": [
"qemu-i386",
"qemu-mips64",
"qemu-mips64el",
"qemu-ppc64le",
"qemu-riscv64",
"qemu-s390x",
"qemu-x86_64"
]
}
前面也提到这个构建过程一般会花费更多时间，我们可以使用 screen 来保证会话不会中断 2
# Debian/Ubuntu 安装
sudo apt install -y screen
# 新建一个名为 build 的会话
screen -S build
# 列出开启的 screen 会话
screen -ls
# 恢复某个 screen 会话（比如，上面的 build）
screen -r build
在 Docker Hub 创建一个仓库，创建一个登录令牌用于登录
sudo docker login -u [username]
Password:
WARNING! Your password will be stored unencrypted in /root/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store
Login Succeeded
创建一个名称为 multiarch 的 buildx 构建实例并立即使用
sudo docker buildx create --name multiarch --use
列出所有的 buildx 构建实例状态，可以看到这个新的 buildx 构建实例还未启动
sudo docker buildx ls
NAME/NODE DRIVER/ENDPOINT STATUS BUILDKIT PLATFORMS
multiarch * docker-container
multiarch0 unix:///var/run/docker.sock inactive
default docker
default default running 20.10.22 linux/arm64, linux/arm/v7, linux/arm/v6, linux/amd64, linux/riscv64, linux/ppc64le, linux/s390x, linux/386
我们可以立即启动这个构建实例（不是必须的）
sudo docker buildx inspect --bootstrap
Name: multiarch
Driver: docker-container
Nodes:
Name: multiarch0
Endpoint: unix:///var/run/docker.sock
Status: running
Buildkit: v0.11.0
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
再次查看所有 buildx 构建实例状态，可以看到已经在运行了
sudo docker buildx ls
NAME/NODE DRIVER/ENDPOINT STATUS BUILDKIT PLATFORMS
multiarch * docker-container
multiarch0 unix:///var/run/docker.sock running v0.11.0 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
default docker
default default running 20.10.22 linux/arm64, linux/arm/v7, linux/arm/v6, linux/amd64, linux/riscv64, linux/ppc64le, linux/s390x, linux/386
开始
现在可以开始构建多架构的 Docker 镜像了，以 book-searcher 为例
# 拉取 book-searcher 源码
git clone https://github.com/book-searcher-org/book-searcher.git
cd book-searcher
# 开始构建并推送到 Docker Hub 仓库（注意替换 dejavumoe/book-searcher:0.8.3）
sudo docker buildx build -t dejavumoe/book-searcher:0.8.3 --platform=linux/arm/v7,linux/arm64,linux/amd64 . --push
开始构建过程
构建成功后，镜像会推送到 Docker Hub，比如文中示例的 book-searcher。
清理
镜像构建并推送完成后，如果没有特殊需求，可以删除构建缓存
# 查看 buildx 构建缓存
sudo docker buildx du
ID RECLAIMABLE SIZE LAST ACCESSED
no7ihggdz0dg9w916xfqdgpo4* true 1.649GB 19 hours ago
zfsooeun4nk9wuuhzkbs13bvg* true 1.631GB 19 hours ago
17luobonj5ah02zvbvvjemxhr true 981.7MB 19 hours ago
g4s8qwcxz9fygcwshw4twe31q true 755.2MB 20 hours ago
nxvw4vi5tb4hqzgc4odldltow true 752.3MB 19 hours ago
w0acj0yo862qpgkz1uc1wv7uv true 735.2MB 20 hours ago
7c3a6xlxsptavooi79v1ous0s true 707.1MB 20 hours ago
4oo7lyzdk6qkbbkl7pp52n5lr* true 706MB 19 hours ago
qut0jkq66o0c2ym8c7ur01hi6* true 699.6MB 19 hours ago
oq1s76dyzvwzducjkyymfu2yf true 682.4MB 20 hours ago
ixdur7y808t04lg654wwnm9f4 true 667.3MB 19 hours ago
25qhl922ornrrslztt4jbw74d true 586.3MB 20 hours ago
uvybomtbmtsoun7cog8qdb8t0 true 583.4MB 20 hours ago
1wvd1baf9mmv78q43gzreivf2 true 222.2MB 20 hours ago
tr82ohutgbuzt2nmmhtwpp33f true 220.6MB 20 hours ago
edsjka5ipnayc0u0lbc354kd8 true 216MB 20 hours ago
hx6x9frep5kojti0babn0edfp true 215.4MB 20 hours ago
yl7xogsqbfp3vqumlex9z70tb true 212.3MB 20 hours ago
mn480l48qvgixqkhhng3vs7kx true 211.1MB 20 hours ago
6hdhnlfc1d6vv0uei4h8x0mbl true 200.9MB 20 hours ago
voaflaun5zqg7rowaeleppipd true 196.2MB 20 hours ago
kmjaktli4z18wwn91lrxwh3ys true 194.3MB 20 hours ago
tson88ja1xdzyvkik9e2rb96r true 188.7MB 20 hours ago
t4t91979x80yuxgs0ym1bc6s6 true 183.6MB 20 hours ago
uzp98pdsf5x3xmr1d1h88jfnt true 180.6MB 20 hours ago
4n9pmxco52u80kgsztr7ja17r true 173.5MB 20 hours ago
ubx1qiodeul94edl5piiwl9ii true 168MB 20 hours ago
wzej45wgvms0cjtd9krs83ac2 true 155.3MB 20 hours ago
c3a2t1xt0wkvjdjdbv6itvv3w true 117.9MB 19 hours ago
iy9bmhb7sr3mkmwnp44m14xkb true 107.3MB 19 hours ago
qjqbzl6oeaccgbaxsaknbszuy true 92.6MB 19 hours ago
uelyg10c9yqlqgoowt89f29lk true 31.22MB 20 hours ago
ly1i0mkejsrjabkukyn8nqr6r true 31.08MB 20 hours ago
ijeolkpn70jlddhbms3vmozwz true 28.79MB 20 hours ago
mzzeina69yltq7jywr20wpl5j true 28.61MB 20 hours ago
up38aojz3dmcyouykvlwe3nh6 true 27.66MB 20 hours ago
9uni4lgitbxyp26d5r24fcyl5 true 26.77MB 20 hours ago
uowpw2a4879redczhhi9kjone true 26.01MB 20 hours ago
fz43v8gbbnqijvrq88kqyy2xo true 25.36MB 20 hours ago
y0xcjgz4ev6fhabfe6x9xr9ye true 22.62MB 20 hours ago
r4qptfigvkvv10vbm3ixl0324 true 21.36MB 19 hours ago
cfdcdeahdo2chctwwascpaf21 true 19.91MB 19 hours ago
v5bagyzlk48ve18j3p3u4bp5g true 19.66MB 19 hours ago
jvd0ew1rxqceq1pf6cuyajpaj true 18.01MB 20 hours ago
ta5440lqabiw13a522z3y17u6 true 17.83MB 20 hours ago
n5zooon2p4vrwf4egvg5g392g true 16.52MB 20 hours ago
mqrnwaojp1f4jbmmcko3qvngj true 9.983MB 20 hours ago
ntec9jovchjk8agmarrbzkpjj true 9.983MB 20 hours ago
pj4x8t87yuzr8m7il57kk2yxt true 9.761MB 20 hours ago
yvj7uskroed3zo9i90ha8jgq1 true 1.139MB 19 hours ago
ibwn6vad7njt1bjmovbi5yd2t true 1.139MB 19 hours ago
yq1ovmhkilofp8ld66d005uzv true 970.8kB 19 hours ago
uhoebp03cgtpt1r85trqke1me true 970.8kB 19 hours ago
phylad5rcv1q9gffeviucbmy3 true 970.8kB 19 hours ago
hdwzqzw6l7558u7tb3x91ax9o true 970.8kB 19 hours ago
hc6667esnksz7svywlorbr29g true 970.8kB 19 hours ago
b1z4vovtou07n78o9yg1kjnw9 true 970.8kB 19 hours ago
toqgn78uygmlj3vjdd8af6207* true 966.7kB 19 hours ago
1kjddgcyuhgcv1pxmtr2v2auc true 413.8kB 20 hours ago
b4rablycd81t6dzpbhn2vilbm true 409.7kB 20 hours ago
uf8p6t2e1z2ydukbg8vwr1mud true 401.5kB 20 hours ago
ot84yzon5gcbhqoh2erzaihtk true 20.93kB 19 hours ago
rb7m8s3o1w2fsfb0keurssyl9 true 20.93kB 19 hours ago
pioklpgrcz3ftdrexyx2whxmy true 20.93kB 19 hours ago
yqq29ynpp5bd9vfio306krccr* true 8.192kB 19 hours ago
9kdh9ldirubp6ulj6h5anjsrn* true 8.192kB 19 hours ago
Reclaimable: 14.79GB
Total: 14.79GB
# 删除 buildx 构建缓存
sudo docker buildx prune
也可以删除 buildx 实例
sudo docker buildx ls
NAME/NODE DRIVER/ENDPOINT STATUS BUILDKIT PLATFORMS
multiarch * docker-container
multiarch0 unix:///var/run/docker.sock running v0.11.0 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
default docker
default default running 20.10.22 linux/arm64, linux/arm/v7, linux/arm/v6, linux/amd64, linux/riscv64, linux/ppc64le, linux/s390x, linux/386
# 停止 buildx 实例
sudo docker buildx stop multiarch
# 删除 buildx 实例
sudo docker buildx rm multiarch
如果构建 Dockerfile 中的基础镜像不支持某些特定的 CPU 架构、某些项目缺少特定的的链接库……等原因会导致镜像构建失败，这就不在本文讨论范畴之内了 😂。
参考信息