kubectl - Core Concepts

Question 1

List all namespaces

Answer 1

kubectl get ns

Question 2

List all pods in all

Answer 2

kubectl get po –all-namespaces

Question 3

List all the pods in the particular namespace

Answer 3

kubectl get po -n

Question 4

List all the services in the particular namespace

Answer 4

kubectl get svc -n

Question 5

List all the pods showing name and namespace with a json path expression

Answer 5

kubectl get pods -o=jsonpath=”{.items[*][‘metadata.name’, ‘metadata.namespace’]}”

Question 6

Create an nginx pod in a default namespace and verify the pod running

Answer 6

1. kubectl run nginx –image=nginx –restart=Never

2. kubectl get po

Question 7

Create the same nginx pod with a yaml file

Answer 7

1. kubectl run nginx –image=nginx –restart=Never –dry-run -o yaml > nginx-pod.yaml
2. kubectl create -f nginx-pod.yaml

Question 8

Output the yaml file of nginx pod

Answer 8

kubectl get po nginx -o yaml

Question 9

Output yaml of nginx pod without cluster-specific information

Answer 9

kubectl get po nginx -o yaml –export

Question 10

Get the complete details of the nginx pod

Answer 10

kubectl describe pod nginx

Question 11

Delete the nginx pod

Answer 11

kubectl delete po nginx

Question 12

Delete the pod created with example-pod.yaml

Answer 12

kubectl delete -f example-pod.yaml

Question 13

Force delete nginx pod

Answer 13

kubectl delete po nginx –grace-period=0 –force

Question 14

Create nginx pod version 1.17.4 and expose port 80

Answer 14

kubectl run nginx –image=nginx:1.17.4 –restart=Never –port=80

Question 15

Change nginx image to 1.15-alpine and verify

Answer 15

1. kubectl set image pod/nginx nginx=nginx:1.15-alpine

2. kubectl describe po nginx

Question 16

Change nginx pod image to 1.15-alpine but you can’t remember the image name

Answer 16

kubectl edit po nginx

Question 17

output just the image version of the nginx pod

Answer 17

kubectl get po nginx -o jsonpath=’{.spec.containers[].image}{“\n”}’

Question 18

Create nginx pod and get to the shell

Answer 18

1. kubectl run nginx –image=nginx –restart=Never

2. kubectl exec -it nginx /bin/sh

Question 19

Get the IP address of the nginx pod

Answer 19

kubectl get po nginx -o wide

Question 20

Create a busybox pod and run command ls while creating it then check the logs

Answer 20

1. kubectl run busybox –image=busybox –restart=Never – ls

2. kubectl logs busybox

Question 21

The busybox pod crashed, check previous logs

Answer 21

kubectl logs busybox -p

Question 22

Create busybox pod with command sleep 3600

Answer 22

kubectl run busybox –image=busybox –restart=Never – /bin/sh -c “sleep 3600”

Question 23

Use the busybox pod to check the connection of the busybox pod

Answer 23

IP=$(kubectl get po nginx -o=jsonpath=’{.status.podIPs[].ip}’); kubectl exec -it busybox – wget -o- $IP

Question 24

Create a busybox pod and echo message ‘How are you’ and delete it manually

Answer 24

1. kubectl run busybox –image=nginx –restart=Never -it – echo “How are you”
2. kubectl delete po busybox

Question 25

Create a busybox pod and echo message ‘How are you’ and have it deleted immediately

Answer 25

kubectl run busybox –image=nginx –restart=Never -it –rm – echo “How are you”

Question 26

List the nginx pod with custom columns POD_NAME and POD_STATUS

Answer 26

kubectl get po -o=custom-columns=”POD_NAME:.metadata.name, POD_STATUS:.status.containerStatuses[].state”

Question 27

List all the pods sorted by name

Answer 27

kubectl get pods –sort-by=.metadata.name

Question 28

List all the pods sorted by created timestamp

Answer 28

kubectl get pods–sort-by=.metadata.creationTimestamp

Question 29

Create a Pod with three busy box containers with commands “ls; sleep 3600;”, “echo Hello World; sleep 3600;” and “echo this is the third container; sleep 3600”

Answer 29

1. kubectl run busybox –image=busybox –restart=Never —dry-run=client -o yaml – bin/sh -c “sleep 3600; ls” > multi-container.yaml
2. Edit yaml to add the containers
3. kubectl create -f multi-container.yaml

Question 30

Check the logs of each container on busybox pod

Answer 30

kubectl logs busybox -c busybox1
kubectl logs busybox -c busybox2
kubectl logs busybox -c busybox3

Question 31

Check the previous logs of the second container busybox2

Answer 31

kubectl logs busybox -c busybox2 –previous

Question 32

Run command ls in the third container busybox3 of the above pod

Answer 32

kubectl exec busybox -c busybox3 – ls

Question 33

Add pod container metrics to file file.log and verify

Answer 33

1. kubectl top pod busybox –container > file.log

2. cat file.log

Question 34

Ensure /var/logs/main.txt exists in container main-container in pod multi-pod

Answer 34

1. kubectl exec -it multi-pod -c main-container – sh

2. cat /var/log/main.txt

Question 35

Run curl localhost from nginx sidecar container

Answer 35

1. kubectl exec -it mult-pod -c sidecar-container – sh
2. apt-get udpate && apt-get install -y curl
3. curl localhost

Question 36

Edit label app on nginx1 pod to be v2

Answer 36

kubectl label po nginx1 app=v2 –overwrite

Question 37

Delete nginx1, nginx2, and nginx3 pods with one command

Answer 37

kubectl delete po nginx{1,2,3}

Question 38

Create an nginx pod with env variable var1=val1

Answer 38

kubectl run nginx –image=nginx –restart=Never –env=var1=val1