[KodeKloud] [CKA] Mock Exam - 2

# MOCK EXAMS, MOCK EXAM – 2 # 4, 6,8 Q. 1 - *info_outline*Question Take a backup of the etcd cluster and save it to `/opt/etcd-backup.db`. - *info_outline*Solution Run the following command to take a backup: ``` export ETCDCTL_API=3 etcdctl snapshot save --endpoints https://[127.0.0.1]:2379 --cacert /etc/kubernetes/pki/etcd/ca.crt --cert /etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key /opt/etcd-backup.db ``` **CheckCompleteIncomplete** - *format_list_bulleted*Details Q. 2 - *info_outline*Question Create a Pod called `redis-storage` with image: `redis:alpine` with a Volume of type `emptyDir` that lasts for the life of the Pod. Specs on the below. - *info_outline*Solution Use the command `kubectl run` and create a pod definition file for `redis-storage` pod and add volume. Alternatively, run the command: `kubectl run redis-storage --image=redis:alpine --dry-run=client -oyaml > redis-storage.yaml` and add volume `emptyDir` in it. Solution manifest file to create a pod `redis-storage` as follows: ``` --- apiVersion: v1 kind: Pod metadata: creationTimestamp:nulllabels: run: redis-storage name: redis-storage spec: containers: - image: redis:alpine name: redis-storage volumeMounts: - mountPath: /data/redis name: temp-volume volumes: - name: temp-volume emptyDir: {} ``` **CheckCompleteIncomplete** - *format_list_bulleted*Details Q. 3 - *info_outline*Question Create a new pod called `super-user-pod` with image `busybox:1.28`. Allow the pod to be able to set `system_time`. The container should sleep for 4800 seconds. - *info_outline*Solution Solution manifest file to create a pod `super-user-pod` as follows: ``` --- apiVersion: v1 kind: Pod metadata: creationTimestamp:nulllabels: run: super-user-pod name: super-user-pod spec: containers: - command: - sleep - "4800" image: busybox:1.28 name: super-user-pod securityContext: capabilities: add: ["SYS_TIME"] dnsPolicy: ClusterFirst restartPolicy: Always ``` **CheckCompleteIncomplete** - *format_list_bulleted*Details Q. 4 - *info_outline*Question A pod definition file is created at `/root/CKA/use-pv.yaml`. Make use of this manifest file and mount the persistent volume called `pv-1`. Ensure the pod is running and the PV is bound. mountPath: `/data` persistentVolumeClaim Name: `my-pvc` - *info_outline*Solution Add a `persistentVolumeClaim` definition to pod definition file. Solution manifest file to create a pvc `my-pvc` as follows: ``` --- apiVersion: v1 kind: PersistentVolumeClaim metadata: name: my-pvc spec: accessModes: - ReadWriteOnce resources: requests: storage: 10Mi ``` And then, update the pod definition file as follows: ``` apiVersion: v1 kind: Pod metadata: creationTimestamp:nulllabels: run: use-pv name: use-pv spec: containers: - image: nginx name: use-pv volumeMounts: - mountPath: "/data" name: mypd volumes: - name: mypd persistentVolumeClaim: claimName: my-pvc ``` Finally, create the pod by running: `kubectl create -f /root/CKA/use-pv.yaml` **CheckCompleteIncomplete** - *format_list_bulleted*Details Q. 5 - *info_outline*Question Create a new deployment called `nginx-deploy`, with image `nginx:1.16` and `1` replica. Next upgrade the deployment to version `1.17` using rolling update. - *info_outline*Solution Explore the `--record` option while creating the deployment while working with the deployment definition file. Then make use of the `kubectl apply` command to create or update the deployment. To create a deployment definition file `nginx-deploy`: ``` $ kubectl create deployment nginx-deploy --image=nginx:1.16 --dry-run=client -o yaml > deploy.yaml ``` To create a resource from definition file and to record: ``` $ kubectl apply -f deploy.yaml --record ``` To view the history of deployment `nginx-deploy`: ``` $ kubectl rollout history deployment nginx-deploy ``` To upgrade the image to next given version: ``` $ kubectl set image deployment/nginx-deploy nginx=nginx:1.17 --record ``` To view the history of deployment `nginx-deploy`: ``` $ kubectl rollout history deployment nginx-deploy ``` **CheckCompleteIncomplete** - *format_list_bulleted*Details Q. 6 - *info_outline*Question Create a new user called `john`. Grant him access to the cluster. John should have permission to `create, list, get, update and delete pods` in the `development` namespace . The private key exists in the location: `/root/CKA/john.key` and csr at `/root/CKA/john.csr`. `Important Note`: As of kubernetes 1.19, the CertificateSigningRequest object expects a `signerName`. Please refer the documentation to see an example. The documentation tab is available at the top right of terminal. - *info_outline*Solution Solution manifest file to create a CSR as follows: ``` --- apiVersion: certificates.k8s.io/v1 kind: CertificateSigningRequest metadata: name: john-developer spec: signerName: kubernetes.io/kube-apiserver-client request: 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 usages: - digital signature - key encipherment - client auth ``` To approve this certificate, run: `kubectl certificate approve john-developer` Next, create a role `developer` and rolebinding `developer-role-binding`, run the command: ``` $ kubectl create role developer --resource=pods --verb=create,list,get,update,delete --namespace=development $ kubectl create rolebinding developer-role-binding --role=developer --user=john --namespace=development ``` To verify the permission from kubectl utility tool: ``` $ kubectl auth can-i update pods --as=john --namespace=development ``` **CheckCompleteIncomplete** - *format_list_bulleted*Details Q. 7 - *info_outline*Question Create a nginx pod called `nginx-resolver` using image `nginx`, expose it internally with a service called `nginx-resolver-service`. Test that you are able to look up the service and pod names from within the cluster. Use the image: `busybox:1.28` for dns lookup. Record results in `/root/CKA/nginx.svc` and `/root/CKA/nginx.pod` - *info_outline*Solution Use the command `kubectl run` and create a nginx pod and busybox pod. Resolve it, nginx service and its pod name from `busybox` pod. To create a pod `nginx-resolver` and expose it internally: ``` kubectl run nginx-resolver --image=nginx kubectl expose pod nginx-resolver --name=nginx-resolver-service --port=80 --target-port=80 --type=ClusterIP ``` To create a pod `test-nslookup`. Test that you are able to look up the service and pod names from within the cluster: ``` kubectl run test-nslookup --image=busybox:1.28 --rm -it --restart=Never -- nslookup nginx-resolver-service kubectl run test-nslookup --image=busybox:1.28 --rm -it --restart=Never -- nslookup nginx-resolver-service > /root/CKA/nginx.svc ``` Get the IP of the `nginx-resolver` pod and replace the dots(.) with hyphon(-) which will be used below. ``` kubectl get pod nginx-resolver -o wide kubectl run test-nslookup --image=busybox:1.28 --rm -it --restart=Never -- nslookup > /root/CKA/nginx.pod ``` **CheckCompleteIncomplete** - *format_list_bulleted*Details Q. 8 - *info_outline*Question Create a static pod on `node01` called `nginx-critical` with image `nginx` and make sure that it is recreated/restarted automatically in case of a failure. Use `/etc/kubernetes/manifests` as the Static Pod path for example. - *info_outline*Solution To create a static pod called `nginx-critical` by using below command: ``` kubectl run nginx-critical --image=nginx --dry-run=client -o yaml > static.yaml ``` Copy the contents of this file or use `scp` command to transfer this file from `controlplane` to `node01` node. ``` root@controlplane:~# scp static.yaml node01:/root/ ``` To know the IP Address of the `node01` node: ``` root@controlplane:~# kubectl get nodes -o wide # Perform SSH root@controlplane:~# ssh node01 OR root@controlplane:~# ssh ``` On `node01` node: Check if static pod directory is present which is `/etc/kubernetes/manifests`, if it's not present then create it. ``` root@node01:~# mkdir -p /etc/kubernetes/manifests ``` Add that complete path to the `staticPodPath` field in the kubelet `config.yaml` file. ``` root@node01:~# vi /var/lib/kubelet/config.yaml ``` now, move/copy the static.yaml to path `/etc/kubernetes/manifests/`. ``` root@node01:~# cp /root/static.yaml /etc/kubernetes/manifests/ ``` Go back to the `controlplane` node and check the status of static pod: ``` root@node01:~# exit logout root@controlplane:~# kubectl get pods ```