所有命令都验证过，有更好的方式，欢迎留言~~~

CKA 习题和真题汇总

• CKA考试经验：报考和考纲 

• CKA ：2019年12月英文原题和分值 

• CKA考试习题：K8S基础概念--API 对象
• CKA考试习题：调度管理- nodeAffinity、podAffinity、Taints
• CKA考试习题：K8S日志、监控与应用管理
• CKA考试习题：网络管理-Pod网络、Ingress、DNS
• CKA考试习题：存储管理-普通卷、PV、PVC
• CKA考试习题：安全管理--Network Policy、serviceaccount、clusterrole
• CKA考试习题：k8s故障排查  
• CKA真题：题目和解析-1  
• CKA真题：题目和解析-2  
• CKA真题：题目和解析-3  
• CKA真题：题目和解析-4  
• CKA真题：题目和解析-5  
• CKA真题：题目和解析-6  

• CKA真题：手动配置TLS BootStrap

更多CKA资料或交流：可加 wei  xin ：wyf19910905

13、不要以持久卷方式挂载

Set configuration context $ kubectl config use-context k8s

Create a pod as follow：

Name：non-persistent-redis

Container image: redis

Name-volume with name: cache-control

Mount path: /data/redis

It should launch in the pre-pod namespace and the volums MUST NOT be persistent

创建一个pod，名为non-presistent-redis,

挂载存储卷，卷名为：cache-control，挂载到本地的：/data/redis目录下，

在名称空间pre-prod里做，不要以持久卷方式挂载。

 

解析：

没有明确要求挂载在node主机上的具体位置，使用随机位置emptyDir:{} ,

如果明确挂载到主机的指定位置和地址，则使用hostPath

答：

emptyDir:{}

 

[root@vms31 opt]# kubectl run non-persistent-redis  --image=redis --generator=run-pod/v1 --dry-run -o yaml > ./13.yaml
[root@vms31 opt]# vim 13.yaml 
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: non-persistent-redis
  name: non-persistent-redis
spec:
  volumes:
  - name: cache-control
    emptyDir: {}
  containers:
  - image: redis
    imagePullPolicy: IfNotPresent
    name: non-persistent-redis
    resources: {}
    volumeMounts:
    - mountPath: /data/redis
      name: cache-control
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}
[root@vms31 opt]# kubectl create ns pre-pod
namespace/pre-pod created
[root@vms31 opt]# kubectl get ns
NAME               STATUS    AGE
default            Active    174d
kube-public        Active    174d
kube-system        Active    174d
ns001              Active    174d
pre-pod            Active    5s
production         Active    174d
website-frontend   Active    1h
[root@vms31 opt]# kubectl apply -f 13.yaml -n pre-pod 
pod/non-persistent-redis created
[root@vms31 opt]# kubectl get pods -n pre-pod 
NAME                   READY     STATUS    RESTARTS   AGE
non-persistent-redis   1/1       Running   0          9s

hostPath

apiVersion: v1
kind: Pod
metadata:
  name: non-presistent-redis
  namespace: pre-prod
spec:
  containers:
  - image: redis
    name: redis
    volumeMounts:
    - mountPath: /data/redis
      name: cache-control
  volumes:
  - name: cache-control
    hostPath:
      # directory location on host
      path: /data/redis
      # this field is optional
      type: DirectoryOrCreate

 

官方文档：

https://kubernetes.io/docs/concepts/storage/volumes/

https://kubernetes.io/docs/concepts/storage/volumes/#emptydir

 

14、Scale：扩缩容

Set configuration context $ kubectl config use-context k8s

Scale the deployment webserver to 6 pods

答：

[root@vms31 opt]# kubectl get deployments.
NAME        DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
nginx-app   3         3         3            3           11h
webserver   1         1         1            1           174d
[root@vms31 opt]# kubectl scale deployment/webserver --replicas=6
deployment.extensions/webserver scaled
[root@vms31 opt]# kubectl get deployments.
NAME        DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
nginx-app   3         3         3            3           11h
webserver   6         6         6            1           174d

 

官网链接： https://kubernetes.io/docs/reference/kubectl/cheatsheet/

 

15、统计node是ready状态，（不包含node的污点，没有调度的）

Set configuration context $ kubectl config use-context k8s

check to see how many nodes are ready （not including nodes tained NoSchedule) and write the number to /opt/nodenum

检查有多少nodes是ready状态，（不包含node的污点，没有调度的），写入数量到 /opt/nodenum

答：

 

# grep -w是精确匹配
# 通过下面命令，统计Ready数量N
kubectl get node | grep -w  Ready | wc -l                              
 

# 通过下面命令，统计NoSchedule和Taints数量M

kubectl describe nodes | grep Taints | grep -I NoSchedule | wc -l  


# 答案填写N减去M得到的值  

echo 2 > /opt/nodenum

 

16、统计pod的CPU

Set configuration context $ kubectl config use-context k8s

From the pod label name=cpu-utilizer, find pods running high CPU workloads and write the name of the pod consuming most CPU to the file /opt/cpu.txt

从标签为 name=cpu-utilizer的所有pod里面，找出cpu使用最高的那个pod，并写入到/opt/cpu.txt（这个文件已经存在）

答：

kubectl top pods -l name=cpu-utilizer -n kube-system

echo '[找到的pod名]' >> /opt/cpu.txt

 

# 如果是找node，则使用

kubectl top nodes