Exploring Kubernetes Networking


Kubernetes networking is a deep and varied subject. In this lab, you will test your knowledge of Kubernetes networking by implementing a networking solution. You will also verify two pods can communicate with one another via your virtual container network.


Log in to the lab server using the credentials provided:

ssh cloud_user@<PUBLIC_IP_ADDRESS>

Fix the Issue Causing Pods Not to Start Up

  1. List the pods to check their status:

    kubectl get pods
  2. Check the node status:

    kubectl get nodes

    It looks like the nodes are NotReady.

  3. Describe a node to see if you can get more info:

    kubectl describe node k8s-worker1

    It looks like kube-proxy, a component that handles networking-related tasks, is stuck starting up.

  4. Check the status of the networking plugin pods:

    kubectl get pods -n kube-system

    The networking pods seem to be missing. Most likely, a networking plugin was never installed.

  5. Install the Calico networking plugin:

    kubectl apply -f https://docs.projectcalico.org/v3.14/manifests/calico.yaml
  6. Check the status of the Nodes and Pods again:

    kubectl get nodes

    They should both be Ready after about a minute.

    kubectl get pods

Verify You Can Communicate between Pods Using the Cluster Network

  1. Verify the two pods can communicate over the network:

    kubectl get pods -o wide
  2. Run curl on the IP address of the cyberdyne-frontend Pod (which will be listed in the output from the previous command):

    kubectl exec testclient -- curl <cyberdyne-frontend_POD_IP>

    The result should be HTML of an Nginx page, meaning the Pods are able to communicate.