vn-affinity-admission-controller

README

Kubernetes Virtual node Admission Webhook

This Kubernetes Admission adds pod affinity and toleration key/values to all pods in a correctly labeled namespace

Project State

Experimental

Pod patches

All pods on a correctly labelled namespace will be patched as follows:

Anti-affinity

spec:
  affinity:
    nodeAffinity:
      preferredDuringSchedulingIgnoredDuringExecution:
      - preference:
          matchExpressions:
          - key: type
            operator: NotIn
            values:
            - virtual-kubelet

Toleration

spec:
  tolerations:
  - key: virtual-kubelet.io/provider
    operator: Exists
  - effect: NoSchedule
    key: azure.com/aci

Attribution

This projects uses the upstream examples found in the following repos:

• https://github.com/caesarxuchao/example-webhook-admission-controller
• https://github.com/kubernetes/kubernetes/tree/release-1.9/test/images/webhook

Massive thanks for all the work that went into crafting reusable examples.

Supported Kubernetes versions

• 1.10
• 1.11

Prerequisites

Please enable the admission webhook feature doc.

Build

make docker_build

Deploy

Enable the relevant Kubernetes Admission controller by adding to following --admission-control and restarting kube-apiserver. See the relevant docs.

MutatingAdmissionWebhook

helm install --name admission-webhook charts/vn-affinity-admission-controller --namespace vn-affinity

helm inspect charts/vn-affinity-admission-controller

Label the namespace you wish enable the webhook to function on

kubectl label namespace default vk-affinity-injection=enabled