`kwok` in Cluster

Deploy kwok in a Cluster #

This document walks you through how to deploy kwok in a Kubernetes cluster.

Variables preparation #

# KWOK repository
KWOK_REPO=kubernetes-sigs/kwok
# Get latest
KWOK_LATEST_RELEASE=$(curl "https://api.github.com/repos/${KWOK_REPO}/releases/latest" | jq -r '.tag_name')

Deploy kwok and set up custom resource definitions (CRDs) #

kubectl apply -f "https://github.com/${KWOK_REPO}/releases/download/${KWOK_LATEST_RELEASE}/kwok.yaml"

Set up default custom resources (CRs) of stages (required) #

NOTE: This configures the pod/node emulation behavior, if not it will do nothing.
kubectl apply -f "https://github.com/${KWOK_REPO}/releases/download/${KWOK_LATEST_RELEASE}/stage-fast.yaml"

Set up default custom resources (CRs) of resource usage (optional) #

This allows to simulate the resource usage of nodes, pods and containers.

kubectl apply -f "https://github.com/${KWOK_REPO}/releases/download/${KWOK_LATEST_RELEASE}/metrics-usage.yaml"

The above configuration sets the CPU and memory usage of all the containers managed by kwok to 1m and to 1Mi respectively. To override the defaults, you can add annotation "kwok.x-k8s.io/usage-cpu" (for cpu usage) and "kwok.x-k8s.io/usage-memory" (for memory usage) with any quantity value you want to the fake pods.

The resource usage simulation used above is annotation-based and the configuration is available at [here][resource usage from annotation]. For the explanation of how it works and more complex resource usage simulation methods, please refer to [ResourceUsage configuration].

The kwok helm chart is listed on the artifact hub.

Variables preparation #

# Temporary directory
KWOK_WORK_DIR=$(mktemp -d)
# KWOK repository
KWOK_REPO=kubernetes-sigs/kwok
# Get latest
KWOK_LATEST_RELEASE=$(curl "https://api.github.com/repos/${KWOK_REPO}/releases/latest" | jq -r '.tag_name')

Render kustomization yaml #

Firstly, generate a kustomization template yaml to the previously-defined temporary directory.

cat <<EOF > "${KWOK_WORK_DIR}/kustomization.yaml"
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
images:
- name: registry.k8s.io/kwok/kwok
  newTag: "${KWOK_LATEST_RELEASE}"
resources:
- "https://github.com/${KWOK_REPO}/kustomize/kwok?ref=${KWOK_LATEST_RELEASE}"
EOF

Next, render it with the prepared variables.

kubectl kustomize "${KWOK_WORK_DIR}" > "${KWOK_WORK_DIR}/kwok.yaml"

kwok deployment #

Finally, we’re able to deploy kwok:

kubectl apply -f "${KWOK_WORK_DIR}/kwok.yaml"

Next steps #

Now, you can use kwok to manage nodes and pods in the Kubernetes cluster.