Kwok Provider

Before using the kwok provider, make sure that you don't have an installed version of Karpenter in your cluster.

Requirements

• Have an image repository that you can build, push, and pull images from.
  • For an example on how to set up an image repository refer to karpenter.sh
• Have a cluster that you can install Karpenter on to.
  • For an example on how to make a cluster in AWS, refer to karpenter.sh

If you use a kind cluster, please set the the following environment variables:

export KWOK_REPO=kind.local
export KIND_CLUSTER_NAME=<kind cluster name, for example, chart-testing>

Installing

make install-kwok
make apply # Run this command again to redeploy if the code has changed

Create a NodePool

Once kwok is installed and Karpenter successfully applies to the cluster, you should now be able to create a NodePool.

cat <<EOF | envsubst | kubectl apply -f -
apiVersion: karpenter.sh/v1
kind: NodePool
metadata:
  name: default
spec:
  template:
    spec:
      requirements:
        - key: kubernetes.io/arch
          operator: In
          values: ["amd64"]
        - key: kubernetes.io/os
          operator: In
          values: ["linux"]
        - key: karpenter.sh/capacity-type
          operator: In
          values: ["spot"]
      nodeClassRef:
        name: default
        kind: KWOKNodeClass
        group: karpenter.kwok.sh
      expireAfter: 720h # 30 * 24h = 720h
  limits:
    cpu: 1000
  disruption:
    consolidationPolicy: WhenEmptyOrUnderutilized
    consolidateAfter: 10s
---
apiVersion: karpenter.kwok.sh/v1alpha1
kind: KWOKNodeClass
metadata:
  name: default
EOF

Taint the existing nodes

kubectl taint nodes <existing node name> CriticalAddonsOnly:NoSchedule

After doing this, you can create a deployment to test node scaling with kwok provider.

Specifying Instance Types

By default, the KWOK provider will create a hypothetical set of instance types that it uses for node provisioning. You can specify a custom set of instance types by providing a JSON file with the list of supported instance options. To do so, set the --instance-types-file-path flag or INSTANCE_TYPES_FILE_PATH environment variable to your custom file's path.

There is an example instance types file in examples/instance_types.json that you can regenerate with make gen_instance_types.

Testing

To test the provider, run make e2etests in the root of the repository.

If you want to test a specific e2e case, run the following command:

export FOCUS="<e2e case name>"
make e2etests

Notes

The kwok provider will have additional labels karpenter.kwok.sh/instance-type, karpenter.kwok.sh/instance-size, karpenter.kwok.sh/instance-family, karpenter.kwok.sh/instance-cpu, and karpenter.sh/instance-memory. These are only available in the kwok provider to select fake generated instance types. These labels will not work with a real Karpenter installation.

Uninstalling

make delete
make uninstall-kwok