容器设备接口(CDI)
容器设备接口(CDI) 是一项规范,旨在标准化设备(如 GPU、FPGA 及其他硬件加速器)如何暴露给容器并被容器使用。其目的是 为在容器化环境中使用硬件设备提供一种更一致、更安全的机制,解决与设备特定设置和配置相关的挑战。
除了使容器能够与设备节点交互外,CDI 还允许你为设备指定额外的配置,例如环境变量、主机挂载(如 共享对象)和可执行钩子(hooks)。
入门(Getting started)
要开始使用 CDI,你需要搭建一个兼容的环境。这包括安装 Docker v27+(已 配置 CDI)以及 Buildx v0.22+。
你还需要使用 JSON 或 YAML 文件在以下位置之一创建 设备规范:
/etc/cdi/var/run/cdi/etc/buildkit/cdi
Note如果你直接使用 BuildKit,可以通过设置
buildkitd.toml配置文件 的cdi段落中的specDirs选项来更改位置。如果你使用带docker驱动的 Docker 守护进程进行 构建,请参阅 配置 CDI 设备 文档。
Note如果你在 WSL 上创建容器构建器,需要确保已安装 Docker Desktop 且已启用 WSL 2 GPU 半虚拟化。还需要 Buildx v0.27+ 才能在容器中 挂载 WSL 库。
使用简单 CDI 规范进行构建(Building with a simple CDI specification)
让我们从一个简单的 CDI 规范开始,它将一个环境变量注入构建环境,并将其写入 /etc/cdi/foo.yaml:
cdiVersion: "0.6.0"
kind: "vendor1.com/device"
devices:
- name: foo
containerEdits:
env:
- FOO=injected检查 default 构建器,确认 vendor1.com/device 被检测为设备:
$ docker buildx inspect
Name: default
Driver: docker
Nodes:
Name: default
Endpoint: default
Status: running
BuildKit version: v0.23.2
Platforms: linux/amd64, linux/amd64/v2, linux/amd64/v3, linux/amd64/v4, linux/386
Labels:
org.mobyproject.buildkit.worker.moby.host-gateway-ip: 172.17.0.1
Devices:
Name: vendor1.com/device=foo
Automatically allowed: false
GC Policy rule#0:
All: false
Filters: type==source.local,type==exec.cachemount,type==source.git.checkout
Keep Duration: 48h0m0s
Max Used Space: 658.9MiB
GC Policy rule#1:
All: false
Keep Duration: 1440h0m0s
Reserved Space: 4.657GiB
Max Used Space: 953.7MiB
Min Free Space: 2.794GiB
GC Policy rule#2:
All: false
Reserved Space: 4.657GiB
Max Used Space: 953.7MiB
Min Free Space: 2.794GiB
GC Policy rule#3:
All: true
Reserved Space: 4.657GiB
Max Used Space: 953.7MiB
Min Free Space: 2.794GiB
现在让我们创建一个 Dockerfile 来使用此设备:
# syntax=docker/dockerfile:1-labs
FROM busybox
RUN --device=vendor1.com/device \
env | grep ^FOO=这里我们使用
RUN --device 命令 并设置 vendor1.com/device,
它请求规范中可用的第一个设备。在本例中它使用 foo,即 /etc/cdi/foo.yaml 中的第一个设备。
Note
RUN --device命令 仅在labs通道 中提供,自 Dockerfile frontend v1.14.0-labs 起,在稳定语法中尚不可用。
现在让我们构建此 Dockerfile:
$ docker buildx build .
[+] Building 0.4s (5/5) FINISHED docker:default
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 155B 0.0s
=> resolve image config for docker-image://docker/dockerfile:1-labs 0.1s
=> CACHED docker-image://docker/dockerfile:1-labs@sha256:9187104f31e3a002a8a6a3209ea1f937fb7486c093cbbde1e14b0fa0d7e4f1b5 0.0s
=> [internal] load metadata for docker.io/library/busybox:latest 0.1s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
ERROR: failed to build: failed to solve: failed to load LLB: device vendor1.com/device=foo is requested by the build but not allowed
它失败了,因为如上 buildx inspect 输出所示,设备 vendor1.com/device=foo 未被构建自动允许:
Devices:
Name: vendor1.com/device=foo
Automatically allowed: false要允许该设备,你可以使用
--allow 标志 配合
docker buildx build 命令:
$ docker buildx build --allow device .
或者,你可以在 CDI 规范中设置 org.mobyproject.buildkit.device.autoallow 注解,以自动允许该设备在所有
构建中使用:
cdiVersion: "0.6.0"
kind: "vendor1.com/device"
devices:
- name: foo
containerEdits:
env:
- FOO=injected
annotations:
org.mobyproject.buildkit.device.autoallow: true现在再次使用 --allow device 标志运行构建:
$ docker buildx build --progress=plain --allow device .
#0 building with "default" instance using docker driver
#1 [internal] load build definition from Dockerfile
#1 transferring dockerfile: 159B done
#1 DONE 0.0s
#2 resolve image config for docker-image://docker/dockerfile:1-labs
#2 DONE 0.1s
#3 docker-image://docker/dockerfile:1-labs@sha256:9187104f31e3a002a8a6a3209ea1f937fb7486c093cbbde1e14b0fa0d7e4f1b5
#3 CACHED
#4 [internal] load metadata for docker.io/library/busybox:latest
#4 DONE 0.1s
#5 [internal] load .dockerignore
#5 transferring context: 2B done
#5 DONE 0.0s
#6 [1/2] FROM docker.io/library/busybox:latest@sha256:f85340bf132ae937d2c2a763b8335c9bab35d6e8293f70f606b9c6178d84f42b
#6 CACHED
#7 [2/2] RUN --device=vendor1.com/device env | grep ^FOO=
#7 0.155 FOO=injected
#7 DONE 0.2s
构建成功,输出显示 FOO 环境变量已按 CDI 规范中的指定被注入到构建环境中。
设置带有 GPU 支持的容器构建器(Set up a container builder with GPU support)
在本节中,我们将向你展示如何使用 NVIDIA GPU 设置
容器构建器。自 Buildx v0.22 起,在创建新的容器构建器时,
如果主机的内核中已安装 GPU 驱动,会自动向容器构建器添加 GPU 请求。这类似于使用
docker run 的 --gpus=all 命令。
现在让我们使用 Buildx 创建一个名为 gpubuilder 的容器构建器:
$ docker buildx create --name gpubuilder --driver-opt "image=moby/buildkit:buildx-stable-1-gpu" --bootstrap
#1 [internal] booting buildkit
#1 pulling image moby/buildkit:buildx-stable-1-gpu
#1 pulling image moby/buildkit:buildx-stable-1-gpu 1.0s done
#1 creating container buildx_buildkit_gpubuilder0
#1 creating container buildx_buildkit_gpubuilder0 8.8s done
#1 DONE 9.8s
gpubuilder
Note我们制作了一个特别定制的 BuildKit 镜像,因为当前的 BuildKit 发布镜像基于 Alpine,不支持 NVIDIA 驱动。 以下镜像基于 Ubuntu,并安装 NVIDIA 客户端库,且在构建期间请求设备时为容器构建器生成 GPU 的 CDI 规范。
让我们检查此构建器:
$ docker buildx inspect gpubuilder
Name: gpubuilder
Driver: docker-container
Last Activity: 2025-07-10 08:18:09 +0000 UTC
Nodes:
Name: gpubuilder0
Endpoint: unix:///var/run/docker.sock
Driver Options: image="moby/buildkit:buildx-stable-1-gpu"
Status: running
BuildKit daemon flags: --allow-insecure-entitlement=network.host
BuildKit version: v0.26.2
Platforms: linux/amd64, linux/amd64/v2, linux/amd64/v3, linux/arm64, linux/riscv64, linux/ppc64le, linux/s390x, linux/386, linux/arm/v7, linux/arm/v6
Labels:
org.mobyproject.buildkit.worker.executor: oci
org.mobyproject.buildkit.worker.hostname: d6aa9cbe8462
org.mobyproject.buildkit.worker.network: host
org.mobyproject.buildkit.worker.oci.process-mode: sandbox
org.mobyproject.buildkit.worker.selinux.enabled: false
org.mobyproject.buildkit.worker.snapshotter: overlayfs
Devices:
Name: nvidia.com/gpu
On-Demand: true
GC Policy rule#0:
All: false
Filters: type==source.local,type==exec.cachemount,type==source.git.checkout
Keep Duration: 48h0m0s
Max Used Space: 488.3MiB
GC Policy rule#1:
All: false
Keep Duration: 1440h0m0s
Reserved Space: 9.313GiB
Max Used Space: 93.13GiB
Min Free Space: 188.1GiB
GC Policy rule#2:
All: false
Reserved Space: 9.313GiB
Max Used Space: 93.13GiB
Min Free Space: 188.1GiB
GC Policy rule#3:
All: true
Reserved Space: 9.313GiB
Max Used Space: 93.13GiB
Min Free Space: 188.1GiB
我们可以看到 nvidia.com/gpu 供应商被检测为构建器中的一个设备,这意味着检测到了驱动。
可选地,你可以使用 nvidia-smi 检查容器是否有 NVIDIA GPU 设备可用:
$ docker exec -it buildx_buildkit_gpubuilder0 nvidia-smi -L
GPU 0: Tesla T4 (UUID: GPU-6cf00fa7-59ac-16f2-3e83-d24ccdc56f84)
使用 GPU 支持进行构建(Building with GPU support)
让我们创建一个将使用 GPU 设备的简单 Dockerfile:
# syntax=docker/dockerfile:1-labs
FROM ubuntu
RUN --device=nvidia.com/gpu nvidia-smi -L现在使用我们之前创建的 gpubuilder 构建器运行构建:
$ docker buildx --builder gpubuilder build --progress=plain .
#0 building with "gpubuilder" instance using docker-container driver
...
#7 preparing device nvidia.com/gpu
#7 0.000 > apt-get update
...
#7 4.872 > apt-get install -y gpg
...
#7 10.16 Downloading NVIDIA GPG key
#7 10.21 > apt-get update
...
#7 12.15 > apt-get install -y --no-install-recommends nvidia-container-toolkit-base
...
#7 17.80 time="2025-04-15T08:58:16Z" level=info msg="Generated CDI spec with version 0.8.0"
#7 DONE 17.8s
#8 [2/2] RUN --device=nvidia.com/gpu nvidia-smi -L
#8 0.527 GPU 0: Tesla T4 (UUID: GPU-6cf00fa7-59ac-16f2-3e83-d24ccdc56f84)
#8 DONE 1.6s
你可能注意到了,步骤 #7 通过安装客户端库和 toolkit 来为 GPU 生成 CDI 规范,从而准备 nvidia.com/gpu
设备。
随后 nvidia-smi -L 命令在容器中使用 GPU 设备执行。输出显示了 GPU UUID。
你可以用以下命令检查容器构建器中生成的 CDI 规范:
$ docker exec -it buildx_buildkit_gpubuilder0 cat /etc/cdi/nvidia.yaml
对于此处使用的 EC2 实例 g4dn.xlarge,它看起来如下:
cdiVersion: 0.6.0
containerEdits:
deviceNodes:
- path: /dev/nvidia-modeset
- path: /dev/nvidia-uvm
- path: /dev/nvidia-uvm-tools
- path: /dev/nvidiactl
env:
- NVIDIA_VISIBLE_DEVICES=void
hooks:
- args:
- nvidia-cdi-hook
- create-symlinks
- --link
- ../libnvidia-allocator.so.1::/usr/lib/x86_64-linux-gnu/gbm/nvidia-drm_gbm.so
hookName: createContainer
path: /usr/bin/nvidia-cdi-hook
- args:
- nvidia-cdi-hook
- create-symlinks
- --link
- libcuda.so.1::/usr/lib/x86_64-linux-gnu/libcuda.so
hookName: createContainer
path: /usr/bin/nvidia-cdi-hook
- args:
- nvidia-cdi-hook
- enable-cuda-compat
- --host-driver-version=570.133.20
hookName: createContainer
path: /usr/bin/nvidia-cdi-hook
- args:
- nvidia-cdi-hook
- update-ldcache
- --folder
- /usr/lib/x86_64-linux-gnu
hookName: createContainer
path: /usr/bin/nvidia-cdi-hook
mounts:
- containerPath: /run/nvidia-persistenced/socket
hostPath: /run/nvidia-persistenced/socket
options:
- ro
- nosuid
- nodev
- bind
- noexec
- containerPath: /usr/bin/nvidia-cuda-mps-control
hostPath: /usr/bin/nvidia-cuda-mps-control
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/bin/nvidia-cuda-mps-server
hostPath: /usr/bin/nvidia-cuda-mps-server
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/bin/nvidia-debugdump
hostPath: /usr/bin/nvidia-debugdump
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/bin/nvidia-persistenced
hostPath: /usr/bin/nvidia-persistenced
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/bin/nvidia-smi
hostPath: /usr/bin/nvidia-smi
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libcuda.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libcuda.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libcudadebugger.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libcudadebugger.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libnvidia-allocator.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libnvidia-allocator.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libnvidia-cfg.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libnvidia-cfg.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libnvidia-gpucomp.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libnvidia-gpucomp.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libnvidia-ml.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libnvidia-ml.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libnvidia-nscq.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libnvidia-nscq.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libnvidia-nvvm.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libnvidia-nvvm.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libnvidia-opencl.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libnvidia-opencl.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libnvidia-pkcs11-openssl3.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libnvidia-pkcs11-openssl3.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libnvidia-pkcs11.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libnvidia-pkcs11.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /usr/lib/x86_64-linux-gnu/libnvidia-ptxjitcompiler.so.570.133.20
hostPath: /usr/lib/x86_64-linux-gnu/libnvidia-ptxjitcompiler.so.570.133.20
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /lib/firmware/nvidia/570.133.20/gsp_ga10x.bin
hostPath: /lib/firmware/nvidia/570.133.20/gsp_ga10x.bin
options:
- ro
- nosuid
- nodev
- bind
- containerPath: /lib/firmware/nvidia/570.133.20/gsp_tu10x.bin
hostPath: /lib/firmware/nvidia/570.133.20/gsp_tu10x.bin
options:
- ro
- nosuid
- nodev
- bind
devices:
- containerEdits:
deviceNodes:
- path: /dev/nvidia0
name: "0"
- containerEdits:
deviceNodes:
- path: /dev/nvidia0
name: GPU-6cf00fa7-59ac-16f2-3e83-d24ccdc56f84
- containerEdits:
deviceNodes:
- path: /dev/nvidia0
name: all
kind: nvidia.com/gpu恭喜你完成了第一次使用 GPU 设备配合 BuildKit 和 CDI 的构建。