Q1. Task: Given an existing Kubernetes cluster running version 1.18.8, upgrade all of the Kubernetes control plane and node components on the master node only to version 1.19.0. You are also expected to upgrade kubelet and kubectl on the master node.

kubectl config use-context mk8s

Note: Be sure to drain the master node before upgrading it and uncordon it after the upgrade. Do not upgrade the worker nodes, etcd, the container manager, the CNI plugin, the DNS service or any other addons.

Answer

A1

kubectl drain <node-to-drain> --ignore-daemonsets
root@controlplane:~# apt update

apt-get update && \
apt-get install -y --allow-change-held-packages kubeadm=1.22.x-00

kubeadm version
kubeadm upgrade plan
kubeadm upgrade apply v1.20.0
apt-get update && \
    apt-get install -y --allow-change-held-packages kubelet=1.22.x-00 kubectl=1.22.x-00

sudo systemctl daemon-reload
sudo systemctl restart kubelet
kubectl uncordon <node-to-drain>

Q2. Task: From the pod label name=cpu-user, find pods running high CPU workloads and write the name of the pod consuiming most CPU to the file /opt/KUTROO401/KUTROO401.txt (which already exists).

kubectl config use-context k8s

Answer

kubectl top -l name=cpu-utilizer –A echo 'pod name' >>/opt/KUT00401/KUT00401.txt

kubectl top pod --sort-by='cpu' --no-headers | head -1

or

kubectl top pods -l name=name-cpu-loader --sort-by=cpu
echo ‘top pod name' >>/opt/KUTR00401/KUTR00401.txt

or

kubectl top node --sort-by='cpu' --no-headers | head -1
kubectl top pod --sort-by='memory' --no-headers | head -1
kubectl top pod --sort-by='cpu' --no-headers | tail -1

Q3. Task: Check to see how many nodes are ready (not including nodes tainted NoSchedule) and wrtie the number to /opt/KUSC00402/kusc00402.txt

kubectl config use-context k8s

Answer

kubectl get nodes
kubectl get node | grep -i ready |wc -l
kubectl describe nodes | grep ready | wc -l
kubectl describe nodes | grep -i taint | grep -i noschedule | wc -l
echo 3 > /opt/KUSC00402/kusc00402.txt

JSONPATH='{range .items[*]}{@.metadata.name}:{range @.status.conditions[*]}{@.type}={@.status};{end}{end}' \
 && kubectl get nodes -o jsonpath="$JSONPATH" | grep "Ready=True" > /opt/KUSC00402/kusc00402.txt

Q4. Task: Monitor the logs of pod foobar and

• Extract log lines corresponding to error unable-to-access-website
• Write them to /opt/KUTR00101/foobar

kubectl config use-context k8s

Answer

kubectl logs foobar  | grep 'unable-to-access-website' > /opt/KULM00201/foobar

Q5. Task: Schedule a pod as follows:

• Name: nginx-kusc00401
• Image: nginx
• Node selector: disk=ssd

kubectl config use-context k8s

Answer

Answer 5

vi pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: nginx-kusc00101
  
spec:
  containers:
  - name: nginx
    image: nginx
    imagePullPolicy: IfNotPresent
  nodeSelector:
    disktype: ssd

kubectl create –f pod.yaml \
kubectl get pods

Q6. Task: List all persistent volumes sorted by capacity, saving the full kubectl output to /opt/KUCC00102/volume_list. Use kubectl 's own functionality for sorting the output, and do not manipulate it any further.

Answer

Answer 6

# List PersistentVolumes sorted by capacity
kubectl get pv --sort-by=.spec.capacity.storage

kubectl get pv  --sort-by = .spec.capacity.storage > /opt/ KUCC00102/volume_list

Q7. Task: Create a file: /opt/KUCC00302/kucc00302.txt that lists all pods that implement service baz in namespace development. The format of the file should be one pod name per line.

Note: selector: name=foo

Answer

Answer 7

kubectl describe service baz –n development

kubectl get pods –l name=foo –n development –o NAME > /opt/KUCC00302/kucc00302.txt

Q8. Task: Create a pod as follows:

• Name: non-persistent-redis
• container Image: redis
• Volume with name: cache-control
• Mount path: /data/redis
• The pod should launch in the staging namespace be persistent.

Answer

Answer 8

vi volume.yaml

apiVersion: v1
kind: Pod
metadata:
  name: non-persistent-redis
  namespace: staging
spec:
  containers:
  - name: redis
    image: redis
    volumeMounts:
    - name: cache-control
      mountPath: /data/redis
  volumes:
  - name: cache-control
    emptyDir: {}

kubectl create –f volume.yaml

kubectl get pods -n staging

Q9. Task: List nginx-dev and nginx-prod pod and delete those pods

Answer

# List PersistentVolumes sorted by capacity
kubectl get pods -o wide

kubectl delete pods nginx-dev nginx-prod

Q10. Task: A Kubernetes worker node, named wk8s-node-0 is in state NotReady, investigate why this is the case, and perform any appropriate steps to bring the node to a Ready state, ensuring that any changes are made permanent.

kubectl config use-context wk8s

You can ssh to the failed node using:

ssh wk8s-node-0   

You can assume elevated privileges on the node with the following command:

sudo -i

Answer

kubectl get nodes  
kubectl describe node wk8s-node-0 #view faulty node info
ssh wk8s-node-0 #enter node01
ps –aux | grep kubelet
sudo -i
systemctl status kubelet
systemctl start kubelet
systemctl enable kubelet

Q11. Task: Given a partially-functioning Kubernetes cluster, identify symptoms of failure on the cluster. Determine the node, the failing service, and take actions to bring up the failed service and restore the health of the cluster. Ensure that any changes are made permanently.

You can ssh to the relevant I nodes:

[student@node-1]$ ssh <nodename>

You can assume elevated privileges on the node with the following command:

[student@nodename]$ sudo –i

Answer

cat /var/lib/kubelet/config.yaml

staticpodpath: /etc/kubernates/manifests
systemctl restart kublet
systemctl enable kublet

Q12. Task: Set the node named ek8s-node-1 as unavailable and reschedule all the pods running on it.

[student@node-1] > ssh ek8s

kubectl config use-context ek8s

Answer

```bash kubectl cordon ek8s-node-1 kubectl drain ek8s-node-1 --delete-local-data --ignore-daemonsets --force ```

Q13. Task: Configure the kubelet systemd-managed service, on the node labelled with name=wk8s-node-1, to launch a pod containing a single container of image httpd named webtool automatically. Any spec files required should be placed in the /etc/kubernetes/manifests directory on the node.

You can ssh to the appropriate node using:

[student@node-1]$ ssh wk8s-node-1

You can assume elevated privileges on the node with the following command:

[student@wk8s-node-1]$ sudo –i

Answer

kubectl cordon ek8s-node-1
kubectl drain ek8s-node-1 --delete-local-data --ignore-daemonsets --force

Q14. Task: Create a pod that echo hello world and then exists. Have the pod deleted automatically when it's completed

You can ssh to the appropriate node using:

[student@node-1]$ ssh wk8s-node-1

You can assume elevated privileges on the node with the following command:

[student@wk8s-node-1]$ sudo –i

Answer

kubectl cordon ek8s-node-1
kubectl drain ek8s-node-1 --delete-local-data --ignore-daemonsets --force

Q15. Task: Get list of all pods in all namespaces and write it to file /opt/pods-list.yaml

Answer

```bash kubectl get pods --all-namespaces > /opt/pods-list.yaml ```

Q16. Task: Create a pod named kucc4 with a single app container for each of the following images running inside (there may be between 1 and 4 images specified)

nginx + redis + memcached + consul

kubectl config use-context k8s

Answer

Multipod question: vi kucc4.yaml

kubectl run kucc8 --image=nginx --dry-run -o yaml > kucc4.yaml

apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  name: kucc4
spec:
  containers:
  - image: nginx
    name: nginx
  - image: redis
    name: redis
  - image: memcached
    name: memcached
  - image: consul
    name: consul

kubectl create -f kucc8.yaml

Q17. Task: You have been asked to create a new ClusterRole for a deployment pipeline and bind it to a specific ServiceAccount scoped to a specific namespace.

• Create a new ClusterRole named deployment-clusterrole, which only allows to create the following resource types:
  • Deployment
  • StatefulSet
  • DaemonSet
• Create a new ServiceAccount name cicd-token in the existing namespace app-team1.
• Bind the new ClusterRole deployment-clusterrole to the new ServiceAccount cicd-token, limited to the namespace app-team1.

kubectl config use-context ek8s

Answer

kubectl create namespace app-team1

kubectl create serviceaccount cicd-token -n app-team1 #create service account

kubectl create clusterrole deployment-clusterrole --verb=create --resource=deployment,statefulset,daemonset  #create cluster role

kubectl create rolebinding deployment-clusterrole --clusterrole=deployment-clusterrole --serviceaccount=default:cicd-token --namespace=app-team1

OR

kubectl create rolebinding cicd-clusterrole --clusterrole=deployment-clusterrole --serviceaccount=app-team1:cicd-token –n app-team1