Udemy Labs - Certified Kubernetes Application Developer - Mock Exam - 1 문제 풀이

1
Deploy a pod named nginx-448839 using the nginx:alpine image.

정답
k run nginx-448839 --image=nginx:alpine

2
Create a namespace named apx-z993845

정답
k create ns apx-z993845

3
Create a new Deployment named httpd-frontend with 3 replicas using image httpd:2.4-alpine

정답
create deployment httpd-frontend --replicas=3 --image=httpd:2.4-alpine

4
Deploy a messaging pod using the redis:alpine image with the labels set to tier=msg.

정답
k run messaging --image=redis:alpine -l tier=msg

5
A replicaset rs-d33393 is created. However the pods are not coming up. Identify and fix the issue.
Once fixed, ensure the ReplicaSet has 4 Ready replicas.

정답

k get replicasets.apps 
k describe rs rs-d33393 
k get po
k describe po rs-d33393-4chgv 
k get rs rs-d33393 -o yaml > 5.yaml
k get rs rs-d33393 -o yaml > 5_md.yaml
vi 5_md.yaml 
k delete rs rs-d33393 --force
k apply -f 5_md.yaml 
k get po

    image: busyboxXXXXXXX -> busybox로 수정

controlplane ~ ➜  cat 5_md.yaml 
apiVersion: apps/v1
kind: ReplicaSet
metadata:
  creationTimestamp: "2025-01-30T14:32:46Z"
  generation: 1
  name: rs-d33393
  namespace: default
spec:
  replicas: 4
  selector:
    matchLabels:
      name: busybox-pod
  template:
    metadata:
      creationTimestamp: null
      labels:
        name: busybox-pod
    spec:
      containers:
      - command:
        - sh
        - -c
        - echo Hello Kubernetes! && sleep 3600
        image: busybox
        imagePullPolicy: IfNotPresent
        name: busybox-container
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
status:
  fullyLabeledReplicas: 4
  observedGeneration: 1
  replicas: 4

6
Create a service messaging-service to expose the redis deployment in the marketing namespace within the cluster on port 6379.

정답

k get deployments.apps -n marketing 
k expose deployment redis -n marketing --port=6379 --name=messaging-service

7
Update the environment variable on the pod webapp-color to use a green background.

정답

k get po webapp-color 
k get po webapp-color -o yaml > 7.yaml
k get po webapp-color -o yaml > 7_md.yaml
vi 7_md.yaml 
k delete po webapp-color --force
k apply -f 7_md.yaml 

pink -> green 으로 수정

controlplane ~ ➜  cat 7_md.yaml 
apiVersion: v1
kind: Pod
metadata:
  annotations:
    cni.projectcalico.org/containerID: d7e1c170d6d5fd082d1fee20e99c1fa743346bfed6b09217ffc78419cd5c25b6
    cni.projectcalico.org/podIP: 172.17.0.7/32
    cni.projectcalico.org/podIPs: 172.17.0.7/32
  creationTimestamp: "2025-01-30T14:22:48Z"
  labels:
    name: webapp-color
  name: webapp-color
  namespace: default
spec:
  containers:
  - env:
    - name: APP_COLOR
      value: green
    image: kodekloud/webapp-color
    imagePullPolicy: Always
    name: webapp-color
    resources: {}
    terminationMessagePath: /dev/termination-log
    terminationMessagePolicy: File
    volumeMounts:
    - mountPath: /var/run/secrets/kubernetes.io/serviceaccount
      name: kube-api-access-4vvcr
      readOnly: true
  dnsPolicy: ClusterFirst
  enableServiceLinks: true
  nodeName: controlplane
  preemptionPolicy: PreemptLowerPriority
  priority: 0
  restartPolicy: Always
  schedulerName: default-scheduler
  securityContext: {}
  serviceAccount: default
  serviceAccountName: default
  terminationGracePeriodSeconds: 30
  tolerations:
  - effect: NoExecute
    key: node.kubernetes.io/not-ready
    operator: Exists
    tolerationSeconds: 300
  - effect: NoExecute
    key: node.kubernetes.io/unreachable
    operator: Exists
    tolerationSeconds: 300
  volumes:
  - name: kube-api-access-4vvcr
    projected:
      defaultMode: 420
      sources:
      - serviceAccountToken:
          expirationSeconds: 3607
          path: token
      - configMap:
          items:
          - key: ca.crt
            path: ca.crt
          name: kube-root-ca.crt
      - downwardAPI:
          items:
          - fieldRef:
              apiVersion: v1
              fieldPath: metadata.namespace
            path: namespace
status:
  conditions:
  - lastProbeTime: null
    lastTransitionTime: "2025-01-30T14:22:58Z"
    status: "True"
    type: PodReadyToStartContainers
  - lastProbeTime: null
    lastTransitionTime: "2025-01-30T14:22:49Z"
    status: "True"
    type: Initialized
  - lastProbeTime: null
    lastTransitionTime: "2025-01-30T14:22:58Z"
    status: "True"
    type: Ready
  - lastProbeTime: null
    lastTransitionTime: "2025-01-30T14:22:58Z"
    status: "True"
    type: ContainersReady
  - lastProbeTime: null
    lastTransitionTime: "2025-01-30T14:22:49Z"
    status: "True"
    type: PodScheduled
  containerStatuses:
  - containerID: containerd://ce0aa5a4aa358b8fe1fe92b09dc0d1d993aab560a6fee1c9959faa93bb609e92
    image: docker.io/kodekloud/webapp-color:latest
    imageID: docker.io/kodekloud/webapp-color@sha256:99c3821ea49b89c7a22d3eebab5c2e1ec651452e7675af243485034a72eb1423
    lastState: {}
    name: webapp-color
    ready: true
    restartCount: 0
    started: true
    state:
      running:
        startedAt: "2025-01-30T14:22:58Z"
    volumeMounts:
    - mountPath: /var/run/secrets/kubernetes.io/serviceaccount
      name: kube-api-access-4vvcr
      readOnly: true
      recursiveReadOnly: Disabled
  hostIP: 192.168.122.169
  hostIPs:
  - ip: 192.168.122.169
  phase: Running
  podIP: 172.17.0.7
  podIPs:
  - ip: 172.17.0.7
  qosClass: BestEffort
  startTime: "2025-01-30T14:22:49Z"

8
Create a new ConfigMap named cm-3392845. Use the spec given on the below.

정답

controlplane ~ ➜  cat 8.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: cm-3392845
data:
  DB_NAME: SQL3322
  DB_HOST: sql322.mycompany.com
  DB_PORT: "3306"

9
Create a new Secret named db-secret-xxdf with the data given (on the below).

참고
https://kubernetes.io/docs/reference/kubectl/generated/kubectl_create/kubectl_create_secret_generic/

정답
k create secret generic db-secret-xxdf --from-literal=DB_Host=sql01 --from-literal=DB_User=root --from-literal=DB_Password=password123

10
Update pod app-sec-kff3345 to run as Root user and with the SYS_TIME capability.

정답

controlplane ~ ➜  cat 10.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: app-sec-kff3345
spec:
  containers:
  - name: ubuntu
    image: ubuntu
    securityContext:
      runAsUser: 0
      capabilities:
        add: ["SYS_TIME"]

11
Export the logs of the e-com-1123 pod to the file /opt/outputs/e-com-1123.logs
It is in a different namespace. Identify the namespace first.

정답

k get po --all-namespaces 
k logs e-com-1123 -n e-commerce 
k logs e-com-1123 -n e-commerce > /opt/outputs/e-com-1123.logs

12
Create a Persistent Volume with the given specification.

정답

controlplane ~ ➜  cat 12.yaml 
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv-analytics
spec:
  capacity:
    storage: 100Mi
  accessModes:
    - ReadWriteMany
  hostPath:
    path: "/pv/data-analytics"

13
Create a redis deployment using the image redis:alpine with 1 replica and label app=redis. Expose it via a ClusterIP service called redis on port 6379. Create a new Ingress Type NetworkPolicy called redis-access which allows only the pods with label access=redis to access the deployment.

정답
먼저 deploy만들고 yaml파일에서 label 추가해줌

k create deployment redis --image=redis:alpine --replicas=1
k get deployments.apps redis -o yaml > redis.yaml
vi redis.yaml 
k apply -f redis.yaml 

deployment expose

   59  k expose deployment/redis --type="ClusterIP" --port 6379

networkpolicy만들기

• 내가 만든 것

controlplane ~ ✖ cat 13.yaml 
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: redis-access
  namespace: default
spec:
  podSelector:
    matchLabels:
       app: redis
  policyTypes:
  - Ingress
  ingress:
  - from:
    - podSelector:
        matchLabels:
          access: redis

• 솔루션: port가 추가되어 있음

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: redis-access
  namespace: default
spec:
  podSelector:
    matchLabels:
       app: redis
  policyTypes:
  - Ingress
  ingress:
  - from:
    - podSelector:
        matchLabels:
          access: redis
    ports:
     - protocol: TCP
       port: 6379

14
Create a Pod called sega with two containers:
Container 1: Name tails with image busybox and command: sleep 3600.
Container 2: Name sonic with image nginx and Environment variable: NGINX_PORT with the value 8080.

참고
https://kubernetes.io/docs/tasks/inject-data-application/define-environment-variable-container/#using-environment-variables-inside-of-your-config

정답

apiVersion: v1
kind: Pod
metadata:
  name: sega
spec:
  containers:
  - image: busybox
    name: tails
    command:
    - sleep
    - "3600"
  - image: nginx
    name: sonic
    env:
    - name: NGINX_PORT
      value: "8080"