新版CKA考试已于2020年9月1日正式上线！
考试模式：线上考试
考试时间：2小时
认证有效期：3年
软件版本：Kubernetes v1.19
重考政策：可接受1次重考
经验水平：中級
题目数量：17题
题库量小：随机的题目重复率极高

考试时可打开两个浏览器Tab，一个是考试窗口，一个用来查阅官方文档](https://kubernetes.io/docs/)

01 Task - 英文

Create a new ClusterRole named deployment-clusterrole that only allows the creation of the following resource types:

• Deployment

• StatefulSet

• DaemonSet
  Create a new ServiceAccount named cicd-token in the existing namespace app-team1.
  Limited to namespace app-team1, bind the new ClusterRole deployment-clusterrole to the new ServiceAccount cicd-token.

  kubectl create ns app-team1 kubectl create serviceaccount cicd-token -n app-team1 kubectl create clusterrole deployment-clusterrole --verb=create --resource=deployment,statefulset,daemonset

  #limted to the namespace app-team1。需要限制的是namespace级别，clusterrolebinding为设置全局，rolebinding正确 kubectl create rolebinding cicd-clusterrole --clusterrole=deployment-clusterrole --serviceaccount=app-team1:cicd-token

02 Task - 英文

Set the node named ek8s-node-1 as unavaliable and reschedule all the pods running on it.

1kubectl cordon ek8s-node-1
2kubectl drain ek8s-node-1 --delete-local-data --ignore-daemonsets --force

03 Task - 英文

Given an existing Kubernetes cluster running version 1.18.8，upgrade all of Kubernetes control plane and node components on the master node only to version 1.19.0。

You are also expected to upgrade kubelet and kubectl on the master node。

Be sure to drain the master node
before upgrading it and uncordon it after the upgrade.
Do not upgrade the worker nodes,etcd,the container manager,the CNI plugin,the DNS service or any other addons.

1apt update
2apt-cache policy kubeadm
3apt-get update && apt-get install -y --allow-change-held-packages kubeadm=1.19.0
4kubeadm version #检查kubeadm版本
5kubectl drain master --ignore-daemonsets --delete-local-data --force #腾空控制平面节点
6sudo kubeadm upgrade plan # 命令查看可升级的版本信息
7sudo kubeadm upgrade apply v1.19.0 --etcd-upgrade=false #查看版本信息时，排除etcd从3.4.3-0升到3.4.7-0
8kubectl uncordon master
9sudo kubeadm upgrade node #升级其他控制面节点
10apt-get update && apt-get install -y --allow-change-held-packages kubelet=1.19.0 kubectl=1.19.0
11#升级其他控制面节点
12sudo systemctl daemon-reload
13sudo systemctl restart kubelet

04 Task - 中文

首先，为运行在https://127.0.0.1:2379 上的现有etcd 实例创建快照并将快照保存到/data/backup/etcd-snapshot.db。

为给定实例创建快照预计能在几秒钟内完成。如果该操作似乎挂起，则命令可能有问题。用ctrl+c 来取消操作，然后重试。

然后还原位于/var/data/etcd-snapshot-previous.db的现有先前快照。

提供了以下TLS证书和密钥，以通过etcdctl连接到服务器。

• ca证书：/opt/KUIN00601/ca.crt
• 客户端证书：/opt/KUIN00601/etcd-client.crt
• 客户端密钥：/opt/KUIN00601/etcd-client.key

1ETCDCTL_API=3 etcdctl --endpoint=https://127.0.0.1:2379 --cert-file=/opt/KUIN00601/etcd-client.crt --key-file=/opt/KUIN00601/etcd-client.key --ca-file=/opt/KUIN00601/ca.crt snapshot save /data/backup/etcd-snapshot.db
2
3ETCDCTL_API=3 etcdctl --endpoint=https://127.0.0.1:2379 --cert-file=/opt/KUIN00601/etcd-client.crt --key-file=/opt/KUIN00601/etcd-client.key --ca-file=/opt/KUIN00601/ca.crt snapshot restore /var/data/etcd-snapshot-previous.db

05 Task - 英文

Create a new NetworkPolicy named allow-port-from-namespace to allow Pods in the existing namespace internal to connect to port 8080 of other Pods in the same namespace.
Ensure that the new NetworkPolicy:

• does not allow access to Pods not listening on port 8080.

• does not allow access from Pods not in namespace internal.

  #network.yaml apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: allow-port-from-namespace namespace: internal spec: podSelector: matchLabels: {

  } policyTypes:

  • Ingress ingress:
  • from:
    • podSelector: {

  } ports: - protocol: TCP port: 8080 #spec.podSelector限定了这个namespace里的pod可以访问 kubectl create -f network.yaml

06 Task - 英文

Reconfigure the existing deployment front-end and add a port specifiction named http exposing port 80/tcp of the existing container nginx.

Create a new service named front-end-svc exposing the container prot http.

Configure the new service to also expose the individual Pods via a NodePort on the nodes on which they are scheduled.

1kubectl get deploy front-end
2kubectl edit deploy front-end -o yaml
3#port specification named http
4#service.yaml
5apiVersion: v1
6kind: Service
7metadata:
8  name: front-end-svc
9  labels:
10    app: nginx
11spec:
12  ports:
13  - port: 80
14    protocol: tcp
15    name: http
16  selector:
17    app: nginx
18  type: NodePort  
19#
20kubectl create -f service.yaml
21#
22kubectl get svc
23
24#或者一条命令搞定,注意会遗漏port specification named http
25kubectl expose deployment front-end --name=front-end-svc --port=80 --tarport=80 --type=NodePort

07 Task - 英文

Create a new nginx Ingress resource as follows:

• Name: ping
• Namespace: ing-internal
• Exposing service hi on path /hi using service port 5678

The avaliability of service hi can be checked using the following command,which should return hi:
curl -kL /hi

1vi ingress.yaml
2#
3apiVersion: networking.k8s.io/v1
4kind: Ingress
5metadata:
6  name: ping
7  namespace: ing-internal
8spec:
9  rules:
10  - http:
11      paths:
12      - path: /hi
13        pathType: Prefix
14        backend:
15          service:
16            name: hi
17            port:
18              number: 5678
19#              
20kubectl create -f ingress.yaml

08 Task - 英文

Scale the deployment presentation to 3 pods.

1kubectl get deployment
2kubectl scale deployment.apps/presentation --replicas=3

09 Task - 英文

Task

Schedule a pod as follows:

• name: nginx-kusc00401

• Image: nginx

• Node selector: disk-spinning

  #yaml apiVersion: v1 kind: Pod metadata: name: nginx-kusc00401 spec: containers:

  • name: nginx image: nginx imagePullPolicy: IfNotPresent nodeSelector: disk: spinning

  kubectl create -f node-select.yaml

10 Task - 英文

Task
Check to see how many nodes are ready (not including nodes tainted NoSchedule)and write the number to /opt/KUSC00402/kusc00402.txt.

1kubectl describe nodes | grep ready|wc -l
2kubectl describe nodes | grep -i taint | grep -i noschedule |wc -l
3echo 3 > /opt/KUSC00402/kusc00402.txt
4
5# 查询集群Ready节点数量
6kubectl get node | grep -i ready |wc -l
7# 找出节点taints、noSchedule
8kubectl describe nodes | grep -i taints | grep -i noschedule |wc -l
9#将得到的减数，写入到文件
10echo 2 > /opt/KUSC00402/kusc00402.txt

11 Task - 英文

Create a pod named kucc8 with a single app container for each of the following images running inside (there may be between 1 and 4 images specified):
nginx + redis + memcached + consul .

1kubectl run kucc8 --image=nginx --dry-run -o yaml > kucc8.yaml
2# vi kucc8.yaml
3apiVersion: v1
4kind: Pod
5metadata:
6  creationTimestamp: null
7  name: kucc8
8spec:
9  containers:
10  - image: nginx
11    name: nginx
12  - image: redis
13    name: redis
14  - image: memcached
15    name: memcached
16  - image: consul
17    name: consul
18#    
19kubectl create -f kucc8.yaml
20#12.07

12 Task - 英文

Task
Create a persistent volume whit name app-config, of capacity 1Gi and access mode ReadOnlyMany . the type of volume is hostPath and its location is /srv/app-config .

1#vi pv.yaml
2apiVersion: v1
3kind: PersistentVolume
4metadata:
5  name: app-config
6spec:
7  capacity:
8    storage: 1Gi
9  accessModes:
10    - ReadOnlyMany
11  hostPath:
12    path: /srv/app-config
13#
14kubectl create -f pv.yaml

13 Task - 英文

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.

1vi pvc.yaml
2#使用指定storageclass创建一个pvc
3apiVersion: v1
4kind: PersistentVolumeClaim
5metadata:
6  name: pv-volume
7spec:
8  accessModes:
9    - ReadWriteOnce
10  volumeMode: Filesystem  
11  resources:
12    requests:
13      storage: 10Mi
14  storageClassName: csi-hostpath-sc
15
16# vi pod-pvc.yaml
17apiVersion: v1
18kind: Pod
19metadata:
20  name: web-server
21spec:
22  containers:
23    - name: web-server
24      image: nginx
25      volumeMounts:
26      - mountPath: "/usr/share/nginx/html"
27        name: my-volume
28  volumes:
29    - name: my-volume
30      persistentVolumeClaim:
31        claimName: pv-volume
32# craete       
33kubectl create -f pod-pvc.yaml
34#edit 修改容量
35kubectl edit pvc pv-volume --record

14 Task - 英文

Task
Monitor the logs of pod bar and:

• Extract log lines corresponding to error unable-to-access-website

• Write them to /opt/KUTR00101/bar

  kubectl logs bar | grep 'unable-to-access-website' > /opt/KUTR00101/bar cat /opt/KUTR00101/bar

15 Task - 英文

Context
Without changing its existing containers,an existing Pod needs to be integrated into Kubernetes’s build-in logging architecture (e.g. kubectl logs). Adding a streaming sidecar container is a good and common way to accomplish this requirement.

Task
Add a busybox sidecar container to the existing Pod big-corp-app. The new sidecar container has to run the following command:

/bin/sh -c tail -n+1 -f /var/log/big-corp-app.log

Use a volume mount named logs to make the file /var/log/big-corp-app.log available to the sidecar container.

Don’t modify the existing container.
Don’t modify the path of the log file,both containers must access it at /var/log/big-corp-app.log.

1#
2kubectl get pod big-corp-app -o yaml 
3#
4apiVersion: v1
5kind: Pod
6metadata:
7  name: big-corp-app
8spec:
9  containers:
10  - name: big-corp-app
11    image: busybox
12    args:
13    - /bin/sh
14    - -c
15    - >
16      i=0;
17      while true;
18      do
19        echo "$(date) INFO $i" >> /var/log/big-corp-app.log;
20        i=$((i+1));
21        sleep 1;
22      done
23    volumeMounts:
24    - name: logs
25      mountPath: /var/log
26  - name: count-log-1
27    image: busybox
28    args: [/bin/sh, -c, 'tail -n+1 -f /var/log/big-corp-app.log']
29    volumeMounts:
30    - name: logs
31      mountPath: /var/log
32  volumes:
33  - name: logs
34    emptyDir: {
35   
36   }
37
38#验证：
39kubectl logs big-corp-app -c count-log-1

16 Task - 英文

Form the pod label name-cpu-loader,find pods running high CPU workloads and write the name of the pod consuming most CPU to the file /opt/KUTR00401/KURT00401.txt(which alredy exists).

查看Pod标签为name=cpu-user-loader 的CPU使用率并且把cpu使用率最高的pod名称写入/opt/KUTR00401/KUTR00401.txt文件里

1kubectl top pods -l name=name-cpu-loader --sort-by=cpu
2echo '排名第一的pod名称' >>/opt/KUTR00401/KUTR00401.txt

17 Task - 英文

Task
A Kubernetes worker node,named wk8s-node-0 is in state NotReady .
Investigate why this is the case,and perform any appropriate steps to bring the node to a Ready state,ensuring that any changes are made permanent.

Yon can ssh to teh failed node using:

ssh wk8s-node-o

You can assume elevated privileges on the node with the following command:

sudo -i

1#名为wk8s-node-1 的节点处于NotReady状态，将其恢复成Ready状态，并且设置为开机自启
2# 连接到NotReady节点
3ssh wk8s-node-0
4#获取权限
5sudo -i
6# 查看服务是否运行正常
7systemctl status kubelet 
8#如果服务非正常运行进行恢复
9systemctl start kubelet
10#设置开机自启
11systemctl enable kubelet