Running kind clusters with GPUs using nvkind

This repo provides a tool called nvkind to create and manage kind clusters with access to GPUs.

Unfortunately, running kind with access to GPUs is not very straightforward. There is no standard way to inject GPUs support into a kind worker node, and even with a series of "hacks" to make it possible, some post processing still needs to be performed to ensure that different sets of GPUs can be isolated to different worker nodes.

The nvkind tool encapsulate the set of steps required to do what is described above. It can either be run directly, or you can import pkg/nvkind as a starting point to write your own tool.

Prerequisites

The following prerequisites are required to build and run nvkind as well as follow all of the examples provided in this README:

Prerequisite | Link ------------ | ------------------------------------- go | https://go.dev/doc/install make | https://www.gnu.org/software/make/#download docker | https://docs.docker.com/get-docker/ kind | https://kind.sigs.k8s.io/docs/user/quick-start/#installation kubectl | https://kubernetes.io/docs/tasks/tools/ helm | https://helm.sh/docs/intro/install/

You must also ensure that you are running on a host with a working NVIDIA driver and an nvidia-container-toolkit configured for use with docker.

Prerequisite | Link ------------------------ | ------------------------------------- nvidia-driver | https://www.nvidia.com/download/index.aspx nvidia-container-toolkit | https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/latest/install-guide.html

Running nvidia-smi -L on a host with a functioning driver should produce output such as the following:

$ nvidia-smi -L
GPU 0: NVIDIA A100-SXM4-40GB (UUID: GPU-4cf8db2d-06c0-7d70-1a51-e59b25b2c16c)
GPU 1: NVIDIA A100-SXM4-40GB (UUID: GPU-4404041a-04cf-1ccf-9e70-f139a9b1e23c)
GPU 2: NVIDIA A100-SXM4-40GB (UUID: GPU-79a2ba02-a537-ccbf-2965-8e9d90c0bd54)
GPU 3: NVIDIA A100-SXM4-40GB (UUID: GPU-662077db-fa3f-0d8f-9502-21ab0ef058a2)
GPU 4: NVIDIA A100-SXM4-40GB (UUID: GPU-ec9d53cc-125d-d4a3-9687-304df8eb4749)
GPU 5: NVIDIA A100-SXM4-40GB (UUID: GPU-3eb87630-93d5-b2b6-b8ff-9b359caf4ee2)
GPU 6: NVIDIA A100-SXM4-40GB (UUID: GPU-8216274a-c05d-def0-af18-c74647300267)
GPU 7: NVIDIA A100-SXM4-40GB (UUID: GPU-b1028956-cfa2-0990-bf4a-5da9abb51763)

Likewise, running the following on a host with a functioning nvidia-container-toolkit that has been configured for docker should produce the same output as above:

$ docker run --runtime=nvidia -e NVIDIA_VISIBLE_DEVICES=all ubuntu:20.04 nvidia-smi -L
GPU 0: NVIDIA A100-SXM4-40GB (UUID: GPU-4cf8db2d-06c0-7d70-1a51-e59b25b2c16c)
GPU 1: NVIDIA A100-SXM4-40GB (UUID: GPU-4404041a-04cf-1ccf-9e70-f139a9b1e23c)
GPU 2: NVIDIA A100-SXM4-40GB (UUID: GPU-79a2ba02-a537-ccbf-2965-8e9d90c0bd54)
GPU 3: NVIDIA A100-SXM4-40GB (UUID: GPU-662077db-fa3f-0d8f-9502-21ab0ef058a2)
GPU 4: NVIDIA A100-SXM4-40GB (UUID: GPU-ec9d53cc-125d-d4a3-9687-304df8eb4749)
GPU 5: NVIDIA A100-SXM4-40GB (UUID: GPU-3eb87630-93d5-b2b6-b8ff-9b359caf4ee2)
GPU 6: NVIDIA A100-SXM4-40GB (UUID: GPU-8216274a-c05d-def0-af18-c74647300267)
GPU 7: NVIDIA A100-SXM4-40GB (UUID: GPU-b1028956-cfa2-0990-bf4a-5da9abb51763)

If you have the nvidia-container-toolkit installed, but you have an error when trying to run the docker command above, skip to the Setup section below to see if some of the configuration steps there resolve the issue.

Setup

With all of the prerequisites installed, run the following commands to configure the nvidia-container-toolkit for use with kind.

sudo nvidia-ctk runtime configure --runtime=docker --set-as-default --cdi.enabled
sudo nvidia-ctk config --set accept-nvidia-visible-devices-as-volume-mounts=true --in-place
sudo systemctl restart docker

The first command ensures that docker is configured for use with the toolkit and that the nvidia runtime is set as its default. The second command enables a feature flag of the toolkit as described in this document). This feature is leveraged to allow us to inject GPU support into each kind worker node.

To ensure that this feature has been enabled correctly, run the following and verify you get output similar to the following:

$ docker run -v /dev/null:/var/run/nvidia-container-devices/all ubuntu:20.04 nvidia-smi -L
GPU 0: NVIDIA A100-SXM4-40GB (UUID: GPU-4cf8db2d-06c0-7d70-1a51-e59b25b2c16c)
GPU 1: NVIDIA A100-SXM4-40GB (UUID: GPU-4404041a-04cf-1ccf-9e70-f139a9b1e23c)
GPU 2: NVIDIA A100-SXM4-40GB (UUID: GPU-79a2ba02-a537-ccbf-2965-8e9d90c0bd54)
GPU 3: NVIDIA A100-SXM4-40GB (UUID: GPU-662077db-fa3f-0d8f-9502-21ab0ef058a2)
GPU 4: NVIDIA A100-SXM4-40GB (UUID: GPU-ec9d53cc-125d-d4a3-9687-304df8eb4749)
GPU 5: NVIDIA A100-SXM4-40GB (UUID: GPU-3eb87630-93d5-b2b6-b8ff-9b359caf4ee2)
GPU 6: NVIDIA A100-SXM4-40GB (UUID: GPU-8216274a-c05d-def0-af18-c74647300267)
GPU 7: NVIDIA A100-SXM4-40GB (UUID: GPU-b1028956-cfa2-0990-bf4a-5da9abb51763)

Install nvkind

To install nvkind using go install, run the following command:

go install github.com/NVIDIA/nvkind/cmd/nvkind@latest

Quickstart

Assuming all of the prerequisites have been meet and setup steps have been followed, the following set of commands can be used to build nvkind, create a set of GPU enabled clusters with it, and then print the set of GPUs available on all nodes of a given cluster.

Build nvkind:

make

Default cluster: One node with all GPUs

Create a default cluster with 1 worker node with access to all GPUs on the machine:

./nvkind cluster create

Example: One node per GPU

Create a cluster with 1 worker node per GPU on the machine:

./nvkind cluster create \
--config-template=examples/one-worker-per-gpu.yaml

Example: Four nodes with two GPUs

Assuming a machine with 8 GPUs, create a cluster with 4 worker nodes and 2 GPUs evenly distributed to each:

./nvkind cluster create \
--name=evenly-distributed-2-by-4 \
--config-template=examples/equally-distributed-gpus.yaml \
--config-values=- \
<<EOF
numWorkers: 4
EOF

Example: Mixed configuration nodes

Assuming a machine with 8 GPUs, create a cluster with 2 worker nodes, the first with access to GPU 0 and the second with access to GPUs 1, 2, and 3.

./nvkind cluster create \
--name=explicit-gpus \
--config-template=examples/explicit-gpus-per-worker.yaml \
--config-values=- \
<<EOF
workers:
- devices: 0
- devices: [1, 2, 3]
EOF

Describing your clusters

List the clusters:

./nvkind cluster list

Print the set of GPUs available on all nodes of a cluster (include a --name flag to select a specific cluster, or omit it to run against the current kubecontext):

./nvkind cluster print-gpus

The output of this command for the last cluster created would look as follows:

[
    {
        "node": "explicit-gpus-worker",
        "gpus": [
            {
                "Index": "0",
                "Name": "NVIDIA A100-SXM4-40GB",
                "UUID": "GPU-4cf8db2d-06c0-7d70-1a51-e59b25b2c16c"
            }
        ]
    },
    {
        "node": "explicit-gpus-worker2",
        "gpus": [
            {
                "Index": "0",
                "Name": "NVIDIA A100-SXM4-40GB",
                "UUID": "GPU-4404041a-04cf-1ccf-9e70-f139a9b1e23c"
            },
            {
                "Index": "1",
                "Name": "NVIDIA A100-SXM4-40GB",
                "UUID": "GPU-79a2ba02-a537-ccbf-2965-8e9d90c0bd54"
            },
            {
                "Index": "2",
                "Name": "NVIDIA A100-SXM4-40GB",
                "UUID": "GPU-662077db-fa3f-0d8f-9502-21ab0ef058a2"
            }
        ]
    }
]

As you can see, nvkind extends the support of the normal kind create cluster call to allow for a templated config file with a set of values. Templates can make use of sprig functions as well as a special numGPUs function to get the total number of GPUs available on a machine. Take a look through the templates in the examples folder to see how these functions are used.

In general, the options for --name. --image, --retain, and --wait are treated the same as they are for the standard kind create cluster call. Take some time to browse through the help menu of the various subcommands to see what other options are available.

Install the k8s-device-plugin

Assuming a cluster has been created as described in the quickstart guide above, the k8s-device-plugin (or gpu-operator) can be installed on the cluster as appropriate. For the purposes of this example, we will install the k8s-device-plugin directly.

First, add the helmrepo for the k8s-device-plugin:

helm repo add nvdp https://nvidia.github.io/k8s-device-plugin
helm repo update

Then pick the cluster you want to install to:

export KIND_CLUSTER_NAME=evenly-distributed-2-by-4

And install the k8s-device-plugin as follows:

helm upgrade -i \
    --kube-context=kind-${KIND_CLUSTER_NAME} \
    --namespace nvidia \
    --create-namespace \
    nvidia-device-plugin nvdp/nvidia-device-plugin

Running the following we can see the pods for the plugin coming online:

$ kubectl --context=kind-${KIND_CLUSTER_NAME} get pod -n nvidia
NAME                         READY   STATUS    RESTARTS   AGE
nvidia-device-plugin-9lfxq   1/1     Running   0          15s
nvidia-device-plugin-hxvzb   1/1     Running   0          15s
nvidia-device-plugin-lgt85   1/1     Running   0          15s
nvidia-device-plugin-r5zbm   1/1     Running   0          15s

Running the following verifies we have 4 nodes with 2 allocatable GPUs each:

$ kub