When using any NoExecute taint on a MachineSet except `node-role.kubernetes.io/infra`, the node will come up with a "uninitialzed" taint:

spec:
  taints:
  - effect: NoSchedule
    key: node.cloudprovider.kubernetes.io/uninitialized
    value: "true"
  - effect: NoExecute
    key: verySpecialPurpose

This is because the azure-cloud-node-manager does not tolerate any other "NoExecute" taints:

$ oc -n openshift-cloud-controller-manager get ds/azure-cloud-node-manager -o json | jq '.spec.template.spec.tolerations'
[
  {
    "effect": "NoSchedule",
    "operator": "Exists"
  },
  {
    "effect": "NoExecute",
    "key": "node-role.kubernetes.io/infra",
    "operator": "Exists"
  },
  {
    "effect": "NoExecute",
    "key": "node.kubernetes.io/unreachable",
    "operator": "Exists",
    "tolerationSeconds": 120
  },
  {
    "effect": "NoExecute",
    "key": "node.kubernetes.io/not-ready",
    "operator": "Exists",
    "tolerationSeconds": 120
  }
]

As a result, customers are unable to create such taints.

    Add the following taint to a MachineSet on Azure:

      taints:
      - effect: NoExecute
        key: verySpecialPurpose

    Following taint is automatically added:

 - effect: NoSchedule key: node.cloudprovider.kubernetes.io/uninitialized

    node to initialize with "NoExecute" taint normally