최신Linux Foundation Certified Kubernetes Administrator (CKA) Program - CKA무료샘플문제
문제1
You must connect to the correct host.
Failure to do so may result in a zero score.
[candidate@base] $ ssh Cka000055
Task
Verify the cert-manager application which has been deployed to your cluster .
Using kubectl, create a list of all cert-manager Custom Resource Definitions (CRDs ) and save it to ~/resources.yaml .
You must use kubectl 's default output format.
Do not set an output format.
Failure to do so will result in a reduced score.
Using kubectl, extract the documentation for the subject specification field of the Certificate Custom Resource and save it to ~/subject.yaml.
You must connect to the correct host.
Failure to do so may result in a zero score.
[candidate@base] $ ssh Cka000055
Task
Verify the cert-manager application which has been deployed to your cluster .
Using kubectl, create a list of all cert-manager Custom Resource Definitions (CRDs ) and save it to ~/resources.yaml .
You must use kubectl 's default output format.
Do not set an output format.
Failure to do so will result in a reduced score.
Using kubectl, extract the documentation for the subject specification field of the Certificate Custom Resource and save it to ~/subject.yaml.
정답:
Task Summary
You need to:
* SSH into the correct node: cka000055
* Use kubectl to list all cert-manager CRDs, and save that list to ~/resources.yaml
* Do not use any output format flags like -o yaml
* Extract the documentation for the spec.subject field of the Certificate custom resource and save it to ~
/subject.yaml
Step-by-Step Instructions
Step 1: SSH into the node
ssh cka000055
Step 2: List cert-manager CRDs and save to a file
First, identify all cert-manager CRDs:
kubectl get crds | grep cert-manager
Then extract them without specifying an output format:
kubectl get crds | grep cert-manager | awk '{print $1}' | xargs kubectl get crd > ~/resources.yaml This saves the default kubectl get output to the required file without formatting flags.
Step 3: Get documentation for spec.subject in the Certificate CRD
Run the following command:
kubectl explain certificate.spec.subject > ~/subject.yaml
This extracts the field documentation and saves it to the specified file.
If you're not sure of the resource, verify it exists:
kubectl get crd certificates.cert-manager.io
Final Command Summary
ssh cka000055
kubectl get crds | grep cert-manager | awk '{print $1}' | xargs kubectl get crd > ~/resources.yaml kubectl explain certificate.spec.subject > ~/subject.yaml
You need to:
* SSH into the correct node: cka000055
* Use kubectl to list all cert-manager CRDs, and save that list to ~/resources.yaml
* Do not use any output format flags like -o yaml
* Extract the documentation for the spec.subject field of the Certificate custom resource and save it to ~
/subject.yaml
Step-by-Step Instructions
Step 1: SSH into the node
ssh cka000055
Step 2: List cert-manager CRDs and save to a file
First, identify all cert-manager CRDs:
kubectl get crds | grep cert-manager
Then extract them without specifying an output format:
kubectl get crds | grep cert-manager | awk '{print $1}' | xargs kubectl get crd > ~/resources.yaml This saves the default kubectl get output to the required file without formatting flags.
Step 3: Get documentation for spec.subject in the Certificate CRD
Run the following command:
kubectl explain certificate.spec.subject > ~/subject.yaml
This extracts the field documentation and saves it to the specified file.
If you're not sure of the resource, verify it exists:
kubectl get crd certificates.cert-manager.io
Final Command Summary
ssh cka000055
kubectl get crds | grep cert-manager | awk '{print $1}' | xargs kubectl get crd > ~/resources.yaml kubectl explain certificate.spec.subject > ~/subject.yaml
문제2
Check to see how many worker nodes are ready (not including nodes tainted NoSchedule) and write the number to /opt/KUCC00104/kucc00104.txt.
Check to see how many worker nodes are ready (not including nodes tainted NoSchedule) and write the number to /opt/KUCC00104/kucc00104.txt.
정답:
문제3
Score: 7%
Task
Given an existing Kubernetes cluster running version 1.20.0, upgrade all of the Kubernetes control plane and node components on the master node only to version 1.20.1.
Be sure to drain the master node before upgrading it and uncordon it after the upgrade.
You are also expected to upgrade kubelet and kubectl on the master node.
Score: 7%
Task
Given an existing Kubernetes cluster running version 1.20.0, upgrade all of the Kubernetes control plane and node components on the master node only to version 1.20.1.
Be sure to drain the master node before upgrading it and uncordon it after the upgrade.
You are also expected to upgrade kubelet and kubectl on the master node.
정답:
SOLUTION:
[student@node-1] > ssh ek8s
kubectl cordon k8s-master
kubectl drain k8s-master --delete-local-data --ignore-daemonsets --force apt-get install kubeadm=1.20.1-00 kubelet=1.20.1-00 kubectl=1.20.1-00 --disableexcludes=kubernetes kubeadm upgrade apply 1.20.1 --etcd-upgrade=false systemctl daemon-reload systemctl restart kubelet kubectl uncordon k8s-master
[student@node-1] > ssh ek8s
kubectl cordon k8s-master
kubectl drain k8s-master --delete-local-data --ignore-daemonsets --force apt-get install kubeadm=1.20.1-00 kubelet=1.20.1-00 kubectl=1.20.1-00 --disableexcludes=kubernetes kubeadm upgrade apply 1.20.1 --etcd-upgrade=false systemctl daemon-reload systemctl restart kubelet kubectl uncordon k8s-master
문제4
Create a persistent volume with name app-data, of capacity 2Gi and access mode ReadWriteMany. The type of volume is hostPath and its location is /srv/app-data.
Create a persistent volume with name app-data, of capacity 2Gi and access mode ReadWriteMany. The type of volume is hostPath and its location is /srv/app-data.
정답:
Persistent Volume
A persistent volume is a piece of storage in a Kubernetes cluster. PersistentVolumes are a cluster-level resource like nodes, which don't belong to any namespace. It is provisioned by the administrator and has a particular file size. This way, a developer deploying their app on Kubernetes need not know the underlying infrastructure. When the developer needs a certain amount of persistent storage for their application, the system administrator configures the cluster so that they consume the PersistentVolume provisioned in an easy way.
Creating Persistent Volume
kind: PersistentVolume
apiVersion: v1
metadata:
name:app-data
spec:
capacity: # defines the capacity of PV we are creating
storage: 2Gi #the amount of storage we are tying to claim
accessModes: # defines the rights of the volume we are creating
- ReadWriteMany
hostPath:
path: "/srv/app-data" # path to which we are creating the volume
Challenge
* Create a Persistent Volume named app-data, with access mode ReadWriteMany, storage classname shared, 2Gi of storage capacity and the host path /srv/app-data.
2. Save the file and create the persistent volume.
Image for post
3. View the persistent volume.
* Our persistent volume status is available meaning it is available and it has not been mounted yet. This status will change when we mount the persistentVolume to a persistentVolumeClaim.
PersistentVolumeClaim
In a real ecosystem, a system admin will create the PersistentVolume then a developer will create a PersistentVolumeClaim which will be referenced in a pod. A PersistentVolumeClaim is created by specifying the minimum size and the access mode they require from the persistentVolume.
Challenge
* Create a Persistent Volume Claim that requests the Persistent Volume we had created above. The claim should request 2Gi. Ensure that the Persistent Volume Claim has the same storageClassName as the persistentVolume you had previously created.
kind: PersistentVolume
apiVersion: v1
metadata:
name:app-data
spec:
accessModes:
- ReadWriteMany
resources:
requests:
storage: 2Gi
storageClassName: shared
2. Save and create the pvc
njerry191@cloudshell:~ (extreme-clone-2654111)$ kubect1 create -f app-data.yaml persistentvolumeclaim/app-data created
3. View the pvc
Image for post
4. Let's see what has changed in the pv we had initially created.
Image for post
Our status has now changed from available to bound.
5. Create a new pod named myapp with image nginx that will be used to Mount the Persistent Volume Claim with the path /var/app/config.
Mounting a Claim
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
name: app-data
spec:
volumes:
- name:congigpvc
persistenVolumeClaim:
claimName: app-data
containers:
- image: nginx
name: app
volumeMounts:
- mountPath: "/srv/app-data "
name: configpvc
A persistent volume is a piece of storage in a Kubernetes cluster. PersistentVolumes are a cluster-level resource like nodes, which don't belong to any namespace. It is provisioned by the administrator and has a particular file size. This way, a developer deploying their app on Kubernetes need not know the underlying infrastructure. When the developer needs a certain amount of persistent storage for their application, the system administrator configures the cluster so that they consume the PersistentVolume provisioned in an easy way.
Creating Persistent Volume
kind: PersistentVolume
apiVersion: v1
metadata:
name:app-data
spec:
capacity: # defines the capacity of PV we are creating
storage: 2Gi #the amount of storage we are tying to claim
accessModes: # defines the rights of the volume we are creating
- ReadWriteMany
hostPath:
path: "/srv/app-data" # path to which we are creating the volume
Challenge
* Create a Persistent Volume named app-data, with access mode ReadWriteMany, storage classname shared, 2Gi of storage capacity and the host path /srv/app-data.
2. Save the file and create the persistent volume.
Image for post
3. View the persistent volume.
* Our persistent volume status is available meaning it is available and it has not been mounted yet. This status will change when we mount the persistentVolume to a persistentVolumeClaim.
PersistentVolumeClaim
In a real ecosystem, a system admin will create the PersistentVolume then a developer will create a PersistentVolumeClaim which will be referenced in a pod. A PersistentVolumeClaim is created by specifying the minimum size and the access mode they require from the persistentVolume.
Challenge
* Create a Persistent Volume Claim that requests the Persistent Volume we had created above. The claim should request 2Gi. Ensure that the Persistent Volume Claim has the same storageClassName as the persistentVolume you had previously created.
kind: PersistentVolume
apiVersion: v1
metadata:
name:app-data
spec:
accessModes:
- ReadWriteMany
resources:
requests:
storage: 2Gi
storageClassName: shared
2. Save and create the pvc
njerry191@cloudshell:~ (extreme-clone-2654111)$ kubect1 create -f app-data.yaml persistentvolumeclaim/app-data created
3. View the pvc
Image for post
4. Let's see what has changed in the pv we had initially created.
Image for post
Our status has now changed from available to bound.
5. Create a new pod named myapp with image nginx that will be used to Mount the Persistent Volume Claim with the path /var/app/config.
Mounting a Claim
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
name: app-data
spec:
volumes:
- name:congigpvc
persistenVolumeClaim:
claimName: app-data
containers:
- image: nginx
name: app
volumeMounts:
- mountPath: "/srv/app-data "
name: configpvc
문제5
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.
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.
정답:
문제6
Score:7%
Task
Create a new PersistentVolumeClaim
* Name: pv-volume
* Class: csi-hostpath-sc
* Capacity: 10Mi
Create a new Pod which mounts the PersistentVolumeClaim as a volume:
* Name: web-server
* Image: nginx
* Mount path: /usr/share/nginx/html
Configure the new Pod to have ReadWriteOnce access on the volume.
Finally, using kubectl edit or kubectl patch expand the PersistentVolumeClaim to a capacity of 70Mi and record that change.
Score:7%
Task
Create a new PersistentVolumeClaim
* Name: pv-volume
* Class: csi-hostpath-sc
* Capacity: 10Mi
Create a new Pod which mounts the PersistentVolumeClaim as a volume:
* Name: web-server
* Image: nginx
* Mount path: /usr/share/nginx/html
Configure the new Pod to have ReadWriteOnce access on the volume.
Finally, using kubectl edit or kubectl patch expand the PersistentVolumeClaim to a capacity of 70Mi and record that change.
정답:
Solution:
vi pvc.yaml
storageclass pvc
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: pv-volume
spec:
accessModes:
- ReadWriteOnce
volumeMode: Filesystem
resources:
requests:
storage: 10Mi
storageClassName: csi-hostpath-sc
# vi pod-pvc.yaml
apiVersion: v1
kind: Pod
metadata:
name: web-server
spec:
containers:
- name: web-server
image: nginx
volumeMounts:
- mountPath: "/usr/share/nginx/html"
name: my-volume
volumes:
- name: my-volume
persistentVolumeClaim:
claimName: pv-volume
# craete
kubectl create -f pod-pvc.yaml
#edit
kubectl edit pvc pv-volume --record
vi pvc.yaml
storageclass pvc
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: pv-volume
spec:
accessModes:
- ReadWriteOnce
volumeMode: Filesystem
resources:
requests:
storage: 10Mi
storageClassName: csi-hostpath-sc
# vi pod-pvc.yaml
apiVersion: v1
kind: Pod
metadata:
name: web-server
spec:
containers:
- name: web-server
image: nginx
volumeMounts:
- mountPath: "/usr/share/nginx/html"
name: my-volume
volumes:
- name: my-volume
persistentVolumeClaim:
claimName: pv-volume
# craete
kubectl create -f pod-pvc.yaml
#edit
kubectl edit pvc pv-volume --record
문제7
Create a busybox pod that runs the command "env" and save the output to "envpod" file See the solution below.
Create a busybox pod that runs the command "env" and save the output to "envpod" file See the solution below.
정답:
kubectl run busybox --image=busybox --restart=Never --rm -it -- env > envpod.yaml
문제8
You must connect to the correct host.
Failure to do so may result in a zero score.
[candidate@base] $ ssh Cka000046
Task
First, create a new StorageClass named local-path for an existing provisioner named rancher.io/local-path .
Set the volume binding mode to WaitForFirstConsumer .
Not setting the volume binding mode or setting it to anything other than WaitForFirstConsumer may result in a reduced score.
Next, configure the StorageClass local-path as the default StorageClass .
You must connect to the correct host.
Failure to do so may result in a zero score.
[candidate@base] $ ssh Cka000046
Task
First, create a new StorageClass named local-path for an existing provisioner named rancher.io/local-path .
Set the volume binding mode to WaitForFirstConsumer .
Not setting the volume binding mode or setting it to anything other than WaitForFirstConsumer may result in a reduced score.
Next, configure the StorageClass local-path as the default StorageClass .
정답:
Task Summary
You need to:
* SSH into cka000046
* Create a StorageClass named local-path using the provisioner rancher.io/local-path
* Set the volume binding mode to WaitForFirstConsumer
* Make this StorageClass the default
Step-by-Step Solution
1## SSH into the correct host
ssh cka000046
## Required. Skipping this = zero score
2## Create a StorageClass YAML file
Create a file named local-path-sc.yaml:
cat <<EOF > local-path-sc.yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: local-path
annotations:
storageclass.kubernetes.io/is-default-class: "true"
provisioner: rancher.io/local-path
volumeBindingMode: WaitForFirstConsumer
EOF
# This:
* Sets WaitForFirstConsumer (as required)
* Marks the class as default using the correct annotation
3## Apply the StorageClass
kubectl apply -f local-path-sc.yaml
4## Verify it's the default StorageClass
kubectl get storageclass
You should see local-path with a (default) marker:
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION
AGE
local-path rancher.io/local-path Delete WaitForFirstConsumer false 10s
Final Command Summary
ssh cka000046
cat <<EOF > local-path-sc.yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: local-path
annotations:
storageclass.kubernetes.io/is-default-class: "true"
provisioner: rancher.io/local-path
volumeBindingMode: WaitForFirstConsumer
EOF
kubectl apply -f local-path-sc.yaml
kubectl get storageclass
You need to:
* SSH into cka000046
* Create a StorageClass named local-path using the provisioner rancher.io/local-path
* Set the volume binding mode to WaitForFirstConsumer
* Make this StorageClass the default
Step-by-Step Solution
1## SSH into the correct host
ssh cka000046
## Required. Skipping this = zero score
2## Create a StorageClass YAML file
Create a file named local-path-sc.yaml:
cat <<EOF > local-path-sc.yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: local-path
annotations:
storageclass.kubernetes.io/is-default-class: "true"
provisioner: rancher.io/local-path
volumeBindingMode: WaitForFirstConsumer
EOF
# This:
* Sets WaitForFirstConsumer (as required)
* Marks the class as default using the correct annotation
3## Apply the StorageClass
kubectl apply -f local-path-sc.yaml
4## Verify it's the default StorageClass
kubectl get storageclass
You should see local-path with a (default) marker:
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION
AGE
local-path rancher.io/local-path Delete WaitForFirstConsumer false 10s
Final Command Summary
ssh cka000046
cat <<EOF > local-path-sc.yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: local-path
annotations:
storageclass.kubernetes.io/is-default-class: "true"
provisioner: rancher.io/local-path
volumeBindingMode: WaitForFirstConsumer
EOF
kubectl apply -f local-path-sc.yaml
kubectl get storageclass
문제9
Score: 7%
Task
Reconfigure the existing deployment front-end and add a port specification named http exposing port 80/tcp of the existing container nginx.
Create a new service named front-end-svc exposing the container port http.
Configure the new service to also expose the individual Pods via a NodePort on the nodes on which they are scheduled.
Score: 7%
Task
Reconfigure the existing deployment front-end and add a port specification named http exposing port 80/tcp of the existing container nginx.
Create a new service named front-end-svc exposing the container port http.
Configure the new service to also expose the individual Pods via a NodePort on the nodes on which they are scheduled.
정답:
Solution:
kubectl get deploy front-end
kubectl edit deploy front-end -o yaml
#port specification named http
#service.yaml
apiVersion: v1
kind: Service
metadata:
name: front-end-svc
labels:
app: nginx
spec:
ports:
- port: 80
protocol: tcp
name: http
selector:
app: nginx
type: NodePort
# kubectl create -f service.yaml
# kubectl get svc
# port specification named http
kubectl expose deployment front-end --name=front-end-svc --port=80 --tarport=80 --type=NodePort
kubectl get deploy front-end
kubectl edit deploy front-end -o yaml
#port specification named http
#service.yaml
apiVersion: v1
kind: Service
metadata:
name: front-end-svc
labels:
app: nginx
spec:
ports:
- port: 80
protocol: tcp
name: http
selector:
app: nginx
type: NodePort
# kubectl create -f service.yaml
# kubectl get svc
# port specification named http
kubectl expose deployment front-end --name=front-end-svc --port=80 --tarport=80 --type=NodePort