A Kubernetes mutating admission webhook, written using Python and FastAPI.
I've written a blog post that explains the whole set up.
The webhook will add a nodeSelector label when a Deployment, StatefulSet, or DaemonSet is created.
The required nodeSelector is set through the NODE_POOL environment variable in the webhook deployment file.
env:
- name: NODE_POOL
value: "kubernetes.io/hostname: docker-desktop"
Example:
kubectl apply -f tests.yaml
deployment.apps/nginx-deployment created
statefulset.apps/nginx-sts created
[2022-11-06 21:50:08,723] INFO: Applying nodeSelector for Deployment/nginx-deployment.
[2022-11-06 21:50:08,723] INFO: Got 'kubernetes.io/hostname: docker-desktop' as nodeSelector label, patching pods...
INFO: 192.168.65.3:33852 - "POST /mutate?timeout=20s HTTP/1.1" 200 OK
[2022-11-06 21:50:08,785] INFO: Applying nodeSelector for StatefulSet/nginx-sts.
[2022-11-06 21:50:08,786] INFO: Got 'kubernetes.io/hostname: docker-desktop' as nodeSelector label, patching pods...