I am trying to setup K8S to work with two Windows Nodes (2019). Everything seems to be working well and the containers are working and accessible using k8s service. But, once I introduce configuration for readiness (or liveness) probes - all fails. The exact error is:

Readiness probe failed: Get http://10.244.1.28:80/test.txt: dial tcp 10.244.1.28:80: connectex: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.

When I try the url from k8s master, it works well and I get 200. However I read that the kubelet is the one executing the probe and indeed when trying from the Windows Node - it cannot be reached (which seems weird because the container is running on that same node). Therefore I assume that the problem is related to some network configuration.

I have a HyperV with External network Virtual Switch configured. K8S is configured to use flannel overlay (vxlan) as instructed here: https://docs.microsoft.com/en-us/virtualization/windowscontainers/kubernetes/network-topologies.

Any idea how to troubleshoot and fix this?

UPDATE: providing the yaml:

apiVersion: v1
kind: Service
metadata:
  name: dummywebapplication
  labels:
    app: dummywebapplication
spec:
  ports:
    # the port that this service should serve on
  - port: 80
    targetPort: 80
  selector:
    app: dummywebapplication
  type: NodePort
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  labels:
    app: dummywebapplication
  name: dummywebapplication
spec:
  replicas: 2
  template:
    metadata:
      labels:
        app: dummywebapplication
      name: dummywebapplication
    spec:
      containers:
      - name: dummywebapplication
        image: <my image>
        readinessProbe:
          httpGet:
            path: /test.txt
            port: 80
          initialDelaySeconds: 15
          periodSeconds: 30
          timeoutSeconds: 60
      nodeSelector:
        beta.kubernetes.io/os: windows

And one more update. In this doc (https://kubernetes.io/docs/setup/windows/intro-windows-in-kubernetes/) it is written:

My Windows node cannot access NodePort service

Local NodePort access from the node itself fails. This is a known limitation. NodePort access works from other nodes or external clients.

I don't know if this is related or not as I could not connect to the container from a different node as stated above. I also tried a service of LoadBalancer type but it didn't provide a different result.