Commands Flashcards
1
Q
List all the namespaces in the cluster
A
kubectl get namespaces
kubectl get ns
2
Q
List all the pods in all namespaces
A
kubectl get po –all-namespaces
3
Q
List all the pods in the particular namespace
A
kubectl get po -n
4
Q
List all the services in the particular namespace
A
kubectl get svc -n
5
Q
List all the pods showing name and namespace with a json path expression
A
kubectl get pods -o=jsonpath=”{.items[*][‘metadata.name’, ‘metadata.namespace’]}”
6
Q
Create an nginx pod in a default namespace and verify the pod running
A
// creating a pod kubectl run nginx --image=nginx --restart=Never // List the pod kubectl get po
7
Q
Create the same nginx pod with a yaml file
A
// get the yaml file with --dry-run flag kubectl run nginx --image=nginx --restart=Never --dry-run -o yaml > nginx-pod.yaml
// cat nginx-pod.yaml
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
labels:
run: nginx
name: nginx
spec:
containers:
- image: nginx
name: nginx
resources: {}
dnsPolicy: ClusterFirst
restartPolicy: Never
status: {}
// create a pod
kubectl create -f nginx-pod.yaml
8
Q
Output the yaml file of the pod you just created ( nginx)
A
kubectl get po nginx -o yaml
9
Q
Output the yaml file of the pod you just created without the cluster-specific information (nginx)
A
kubectl get po nginx -o yaml –export
10
Q
Get the complete details of the pod you just created (nginx)
A
kubectl describe pod nginx
11
Q
Delete the pod you just created ( nginx, nginx-pod.yaml)
A
kubectl delete po nginx
kubectl delete -f nginx-pod.yaml
12
Q
Delete the pod you just created without any delay (force delete) (nginx)
A
kubectl delete po nginx –grace-period=0 –force
13
Q
Create the nginx pod with version 1.17.4 and expose it on port 80
A
kubectl run nginx –image=nginx:1.17.4 –restart=Never –port=80
14
Q
Change the Image version to 1.15-alpine for the pod you just created and verify the image version is updated
A
kubectl set image pod/nginx nginx=nginx:1.15-alpine
kubectl describe po nginx
// another way it will open vi editor and change the version
kubeclt edit po nginx
kubectl describe po nginx
15
Q
Change the Image version back to 1.17.1 for the pod you just updated and observe the changes
A
kubectl set image pod/nginx nginx=nginx:1.17.1
kubectl describe po nginx
kubectl get po nginx -w # watch it
16
Q
Check the Image version without the describe command
A
kubectl get po nginx -o jsonpath=’{.spec.containers[].image}{“\n”}’
17
Q
Create the nginx pod and execute the simple shell on the pod
A
// creating a pod kubectl run nginx --image=nginx --restart=Never
// exec into the pod kubectl exec -it nginx /bin/sh
18
Q
Get the IP Address of the pod you just created
A
kubectl get po nginx -o wide
19
Q
Create a busybox pod and run command ls while creating it and check the logs
A
kubectl run busybox –image=busybox –restart=Never – ls
kubectl logs busybox
20
Q
If pod crashed check the previous logs of the pod
A
kubectl logs busybox -p
21
Q
Create a busybox pod with command sleep 3600
A
kubectl run busybox –image=busybox –restart=Never – /bin/sh -c “sleep 3600”
22
Q
Check the connection of the nginx pod from the busybox pod
A
kubectl get po nginx -o wide
// check the connection kubectl exec -it busybox -- wget -o-
23
Q
Create a busybox pod and echo message ‘How are you’ and delete it manually
A
kubectl run busybox –image=nginx –restart=Never -it – echo “How are you”
kubectl delete po busybox
24
Q
Create a busybox pod and echo message ‘How are you’ and have it deleted immediately
A
// notice the –rm flag
kubectl run busybox –image=nginx –restart=Never -it –rm – echo “How are you”
25
Create an nginx pod and list the pod with different levels of verbosity
```
// create a pod
kubectl run nginx --image=nginx --restart=Never --port=80
```
```
// List the pod with different verbosity
kubectl get po nginx --v=7
kubectl get po nginx --v=8
kubectl get po nginx --v=9
```
26
26.
List the nginx pod with custom columns POD_NAME and POD_STATUS26. List the nginx pod with custom columns POD_NAME and POD_STATUS
kubectl get po -o=custom-columns="POD_NAME:.metadata.name, POD_STATUS:.status.containerStatuses[].state"
27
27. List all the pods sorted by name
kubectl get pods --sort-by=.metadata.name
28
28. List all the pods sorted by created timestamp
kubectl get pods--sort-by=.metadata.creationTimestamp
29
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” respectively and check the status
```
// first create single container pod with dry run flag
kubectl run busybox --image=busybox --restart=Never --dry-run -o yaml -- bin/sh -c "sleep 3600; ls" > multi-container.yaml
```
// edit the pod to following yaml and create it
kubectl create -f multi-container.yaml
kubectl get po busybox
Via API
```
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
labels:
run: busybox
name: busybox
spec:
containers:
- args:
- bin/sh
- -c
- ls; sleep 3600
image: busybox
name: busybox1
resources: {}
- args:
- bin/sh
- -c
- echo Hello world; sleep 3600
image: busybox
name: busybox2
resources: {}
- args:
- bin/sh
- -c
- echo this is third container; sleep 3600
image: busybox
name: busybox3
resources: {}
dnsPolicy: ClusterFirst
restartPolicy
```
30
30. Check the logs of each container that you just created in question 29...below
```
// first create single container pod with dry run flag
kubectl run busybox --image=busybox --restart=Never --dry-run -o yaml -- bin/sh -c "sleep 3600; ls" > multi-container.yaml
```
// edit the pod to following yaml and create it
kubectl create -f multi-container.yaml
kubectl get po busybox
kubectl logs busybox -c busybox1
kubectl logs busybox -c busybox2
kubectl logs busybox -c busybox3
31
31. Check the previous logs of the second container busybox2 if any
kubectl logs busybox -c busybox2 --previous
32
32. Run command ls in the third container busybox3 of the above pod
kubectl exec busybox -c busybox3 -- ls
33
33. Show metrics of the above pod containers and puts them into the file.log and verify
```
// first create single container pod with dry run flag
kubectl run busybox --image=busybox --restart=Never --dry-run -o yaml -- bin/sh -c "sleep 3600; ls" > multi-container.yaml
```
// edit the pod to following yaml and create it
kubectl create -f multi-container.yaml
kubectl get po busybox
kubectl top pod busybox --containers
// putting them into file
kubectl top pod busybox --containers > file.log
cat file.log
34
34. Create a Pod with main container busybox and which executes this “while true; do echo ‘Hi I am from Main container’ >> /var/log/index.html; sleep 5; done” and with sidecar container with nginx image which exposes on port 80. Use emptyDir Volume and mount this volume on path /var/log for busybox and on path /usr/share/nginx/html for nginx container. Verify both containers are running.
```
// create an initial yaml file with this
kubectl run multi-cont-pod --image=busbox --restart=Never --dry-run -o yaml > multi-container.yaml
// edit the yml as below and create it
kubectl create -f multi-container.yaml
kubectl get po multi-cont-pod
```
API Version:
```
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
labels:
run: multi-cont-pod
name: multi-cont-pod
spec:
volumes:
- name: var-logs
emptyDir: {}
containers:
- image: busybox
command: ["/bin/sh"]
args: ["-c", "while true; do echo 'Hi I am from Main container' >> /var/log/index.html; sleep 5;done"]
name: main-container
resources: {}
volumeMounts:
- name: var-logs
mountPath: /var/log
- image: nginx
name: sidecar-container
resources: {}
ports:
- containerPort: 80
volumeMounts:
- name: var-logs
mountPath: /usr/share/nginx/html
dnsPolicy: ClusterFirst
restartPolicy: Never
status: {}
```
35
35. Exec into both containers and verify that main.txt exist and query the main.txt from sidecar container with curl localhost
// exec into main container
kubectl exec -it multi-cont-pod -c main-container -- sh
cat /var/log/main.txt
// exec into sidecar container
kubectl exec -it multi-cont-pod -c sidecar-container -- sh
cat /usr/share/nginx/html/index.html
// install curl and get default page
kubectl exec -it multi-cont-pod -c sidecar-container -- sh
# apt-get update && apt-get install -y curl
# curl localhost
36
36. Get the pods with label information
kubectl get pods --show-labels
37
37. Create 5 nginx pods in which two of them is labeled env=prod and three of them is labeled env=dev
kubectl run nginx-dev1 --image=nginx --restart=Never --labels=env=dev
kubectl run nginx-dev2 --image=nginx --restart=Never --labels=env=dev
kubectl run nginx-dev3 --image=nginx --restart=Never --labels=env=dev
kubectl run nginx-prod1 --image=nginx --restart=Never --labels=env=prod
kubectl run nginx-prod2 --image=nginx --restart=Never --labels=env=prod
38
38. Verify all the pods are created with correct labels
kubeclt get pods --show-labels
39
39. Get the pods with label env=dev
kubectl get pods -l env=dev
40
40. Get the pods with label env=dev and also output the labels
kubectl get pods -l env=dev --show-labels
41
41. Get the pods with label env=prod
kubectl get pods -l env=prod
42
42. Get the pods with label env=prod and also output the labels
kubectl get pods -l env=prod --show-labels
43
43. Get the pods with label env
kubectl get pods -L env
44
44. Get the pods with labels env=dev and env=prod
kubectl get pods -l 'env in (dev,prod)'
45
45. Get the pods with labels env=dev and env=prod and output the labels as well
kubectl get pods -l 'env in (dev,prod)' --show-labels
46
46. Change the label for one of the pod to env=uat and list all the pods to verify
kubectl label pod/nginx-dev3 env=uat --overwrite
| kubectl get pods --show-labels
47
47. Remove the labels for the pods that we created now and verify all the labels are removed
kubectl label pod nginx-dev{1..3} env-
kubectl label pod nginx-prod{1..2} env-
kubectl get po --show-labels
48
48. Let’s add the label app=nginx for all the pods and verify
kubectl label pod nginx-dev{1..3} app=nginx
kubectl label pod nginx-prod{1..2} app=nginx
kubectl get po --show-labels
49
49. Get all the nodes with labels (if using minikube you would get only master node)
kubectl get nodes --show-labels
50
50. Label the node (minikube if you are using) nodeName=nginxnode
kubectl label node minikube nodeName=nginxnode
51
51. Create a Pod that will be deployed on this node with the label nodeName=nginxnode
```
kubectl run nginx --image=nginx --restart=Never --dry-run -o yaml > pod.yaml
// add the nodeSelector like below and create the pod
kubectl create -f pod.yaml
```
```
API Version:
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
labels:
run: nginx
name: nginx
spec:
nodeSelector:
nodeName: nginxnode
containers:
- image: nginx
name: nginx
resources: {}
dnsPolicy: ClusterFirst
restartPolicy: Never
status: {}
```
52
52. Verify the pod that it is scheduled with the node selector
kubectl describe po nginx | grep Node-Selectors
53
53. Verify the pod nginx that we just created has this label
kubectl describe po nginx | grep Labels
54
54. Annotate the pods with name=webapp
kubectl annotate pod nginx-dev{1..3} name=webapp
| kubectl annotate pod nginx-prod{1..2} name=webapp
55
55. Verify the pods that have been annotated correctly
kubectl annotate pod nginx-dev{1..3} name=webapp
kubectl annotate pod nginx-prod{1..2} name=webapp
kubectl describe po nginx-dev{1..3} | grep -i annotations
| kubectl describe po nginx-prod{1..2} | grep -i annotations
56
56. Remove the annotations on the pods and verify
kubectl annotate pod nginx-dev{1..3} name-
kubectl annotate pod nginx-prod{1..2} name-
kubectl describe po nginx-dev{1..3} | grep -i annotations
kubectl describe po nginx-prod{1..2} | grep -i annotations
57
57. Remove all the pods that we created so far
kubectl delete po --all
58
58. Create a deployment called webapp with image nginx with 5 replicas
```
kubectl create deploy webapp --image=nginx --dry-run -o yaml > webapp.yaml
// change the replicas to 5 in the yaml and create it
kubectl create -f webapp.yaml
```
API Version:
```
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: webapp
name: webapp
spec:
replicas: 5
selector:
matchLabels:
app: webapp
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: webapp
spec:
containers:
- image: nginx
name: nginx
resources: {}
status: {}
```
59
59. Get the deployment you just created with labels
kubectl get deploy webapp --show-labels
60
60. Output the yaml file of the deployment you just created
```
kubectl create deploy webapp --image=nginx --dry-run -o yaml > webapp.yaml
// change the replicas to 5 in the yaml and create it
kubectl create -f webapp.yaml
```
kubectl get deploy webapp -o yaml
61
61. Get the pods of this deployment
```
kubectl create deploy webapp --image=nginx --dry-run -o yaml > webapp.yaml
// change the replicas to 5 in the yaml and create it
kubectl create -f webapp.yaml
```
```
// get the label of the deployment
kubectl get deploy --show-labels
// get the pods with that label
kubectl get pods -l app=webapp
```
62
62. Scale the deployment from 5 replicas to 20 replicas and verify
```
kubectl create deploy webapp --image=nginx --dry-run -o yaml > webapp.yaml
// change the replicas to 5 in the yaml and create it
kubectl create -f webapp.yaml
```
kubectl scale deploy webapp --replicas=20
| kubectl get po -l app=webapp
63
63. Get the deployment rollout status
kubectl scale deploy webapp --replicas=20
kubectl get po -l app=webapp
kubectl rollout status deploy webapp
64
64. Get the replicaset that created with this deployment
kubectl scale deploy webapp --replicas=20
kubectl get po -l app=webapp
kubectl get rs -l app=webapp
65
65. Get the yaml of the replicaset and pods of this deployment
kubectl scale deploy webapp --replicas=20
kubectl get po -l app=webapp
kubectl get rs -l app=webapp -o yaml
| kubectl get po -l app=webapp -o yaml
