text: Title: Need NodePort test for mixed-OS clusters
  Body: We need a test case that will verify that NodePort works on all nodes in the cluster for a Windows application.
  
  Here's an example manual test:
  
  Run `kubectl create -f` with this yaml
  
  ```yaml
  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: iis-2019
    labels:
      app: iis-2019
  spec:
    replicas: 1
    template:
      metadata:
        name: iis-2019
        labels:
          app: iis-2019
      spec:
        containers:
        - name: iis
          image: mcr.microsoft.com/windows/servercore/iis:windowsservercore-ltsc2019
          resources:
            limits:
              cpu: 1
              memory: 800m
            requests:
              cpu: .1
              memory: 300m
          ports:
            - containerPort: 80
        nodeSelector:
          "beta.kubernetes.io/os": windows
    selector:
      matchLabels:
        app: iis-2019
  ---
  apiVersion: v1
  kind: Service
  metadata:
    name: iis
  spec:
    type: NodePort
    ports:
    - protocol: TCP
      port: 80
    selector:
      app: iis-2019
  ```
  
  Once the pod is running, get the nodeport and make sure it's accessible on each node IP for that port.
  
  
  ```
  $ kubectl get svc
  NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)        AGE
  iis          NodePort    10.0.88.64   <none>        80:30220/TCP   10m
  kubernetes   ClusterIP   10.0.0.1     <none>        443/TCP        10d
  azureuser@k8s-master-30163644-0:~$ kubectl get node -o wide
  NAME                        STATUS   ROLES   AGE   VERSION   INTERNAL-IP   EXTERNAL-IP   OS-IMAGE                    KERNEL-VERSION   CONTAINER-RUNTIME
  3016k8s010                  Ready    agent   10d   v1.13.2   10.240.0.35   <none>        Windows Server Datacenter   10.0.17763.253
                              docker://18.9.0
  3016k8s011                  Ready   agent   10d   v1.13.2   10.240.0.96   <none>   Windows Server Datacenter   10.0.17763.253
                              docker://18.9.0
  k8s-linuxpool1-30163644-0   Ready   agent    10d   v1.13.2   10.240.0.4     <none>   Ubuntu 16.04.5 LTS   4.15.0-1036-azure   docker://3.0.1
  k8s-linuxpool1-30163644-1   Ready   agent    10d   v1.13.2   10.240.0.127   <none>   Ubuntu 16.04.5 LTS   4.15.0-1036-azure   docker://3.0.1
  k8s-master-30163644-0       Ready   master   10d   v1.13.2   10.255.255.5   <none>   Ubuntu 16.04.5 LTS   4.15.0-1036-azure   docker://3.0.1
  azureuser@k8s-master-30163644-0:~$ curl -s -o /dev/null -w "%{http_code}" http://10.240.0.35:30220
  200azureuser@k8s-master-30163644-0:~$ curl -s -o /dev/null -w "%{http_code}" http://10.240.0.96:30220
  200azureuser@k8s-master-30163644-0:~$ curl -s -o /dev/null -w "%{http_code}" http://10.240.0.4:30220
  200azureuser@k8s-master-30163644-0:~$ curl -s -o /dev/null -w "%{http_code}" http://10.240.0.127:30220
  200
  ```
  
  /good-first-issue
  /kind test
  /sig windows
  