CKAD 考試習題練習，Kubernetes

如何參與 CNCF 的 Kubernetes 項目呢？https://github.com/tanjunchen/ParticipateCommunity
Kubernetes CKAD 練習

# 核心概念（13％）
# 多容器 Pod（10％）
# Pod 設計（20％）
# 狀態持久性（8％）
# 配置（18％）
# 可觀察性（18％）
# 服務和網絡（13％）

# 瞭解 Kubernetes API 原語，創建和配置基本 Pod

1. 列出集羣中的所有命名空間

kubectl get namespaces
kubectl get ns

2. 列出所有命名空間中的所有 Pod

kubectl get po --all-namespaces

3. 列出特定命名空間中的所有 Pod

kubectl get pod -n kube-system
kubectl get pod -n 命名空間名稱

4. 列出特定命名空間中的所有 Service

kubectl get svc --all-namespaces
kubectl get svc -n 命名空間名稱
kubectl get svc -n default

5. 用 json 路徑表達式列出所有顯示名稱和命名空間的 Pod

kubectl get pods -o=jsonpath="{. items[*]['metadata. name','metadata. namespace']}" --all-namespaces --sort-by=metadata. name

kubectl get pods -o=jsonpath="{. items[*]['metadata. name','metadata. namespace']}" --all-namespaces

6. 在默認命名空間中創建一個 Nginx Pod，並驗證 Pod 是否正在運行

kubectl run nginx --image=nginx
以上命令
kubectl run --generator=deployment/apps. v1 is DEPRECATED and will be removed in a future version.  Use kubectl run --generator=run-pod/v1 or kubectl create instead

kubectl run nginx --image=nginx --restart=Never
會直接產生 nginx  後面不會產生隨機數

7. 使用 yaml 文件創建相同的 Nginx Pod

kubectl run nginx --image=nginx --restart=Never --dry-run -o yaml > nginx. yaml

nginx. yaml 爲

```
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: nginx
  name: nginx
spec:
  containers:
  - image: nginx
    name: nginx
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Never
status: {}
```

8. 輸出剛創建的 Pod 的 yaml 文件

kubectl get po nginx -o yaml

9. 輸出剛創建的 Pod 的 yaml 文件，並且其中不包含特定於集羣的信息

kubectl get po nginx -o yaml --export

```
Flag --export has been deprecated, This flag is deprecated and will be removed in future. 
apiVersion: v1
kind: Pod
metadata:
  annotations:
    cni. projectcalico. org/podIP: 10. 244. 1. 4/32
    cni. projectcalico. org/podIPs: 10. 244. 1. 4/32
  creationTimestamp: null
  labels:
    run: nginx
  name: nginx
  selfLink: /api/v1/namespaces/default/pods/nginx
spec:
  containers:
  - image: nginx
    imagePullPolicy: Always
    name: nginx
    resources: {}
    terminationMessagePath: /dev/termination-log
    terminationMessagePolicy: File
    volumeMounts:
    - mountPath: /var/run/secrets/kubernetes. io/serviceaccount
      name: default-token-6t2vf
      readOnly: true
  dnsPolicy: ClusterFirst
  enableServiceLinks: true
  nodeName: k8s-node01
  priority: 0
  restartPolicy: Never
  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: default-token-6t2vf
    secret:
      defaultMode: 420
      secretName: default-token-6t2vf
status:
  phase: Pending
  qosClass: BestEffort
```

10. 獲取剛剛創建的 Pod 的完整詳細信息

kubectl describe pod nginx

```
Name:         nginx
Namespace:    default
Priority:     0
Node:         k8s-node01/192. 168. 17. 151
Start Time:   Sun, 05 Jan 2020 18:57:52 -0800
Labels:       run=nginx
Annotations:  cni. projectcalico. org/podIP: 10. 244. 1. 4/32
              cni. projectcalico. org/podIPs: 10. 244. 1. 4/32
Status:       Running
IP:           10. 244. 1. 4
IPs:
  IP:  10. 244. 1. 4
Containers:
  nginx:
    Container ID:   docker://3d9b8b7aba7c10b3f1fbdd470dee702bc5c0e70a46157674574b3b20bd629335
    Image:          nginx
    Image ID:       docker-pullable://nginx@sha256:b2d89d0a210398b4d1120b3e3a7672c16a4ba09c2c4a0395f18b9f7999b768f2
    Port:           <none>
    Host Port:      <none>
    State:          Running
      Started:      Sun, 05 Jan 2020 18:57:57 -0800
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes. io/serviceaccount from default-token-6t2vf (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  default-token-6t2vf:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-6t2vf
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node. kubernetes. io/not-ready:NoExecute for 300s
                 node. kubernetes. io/unreachable:NoExecute for 300s
Events:
  Type    Reason     Age   From                 Message
  ----    ------     ----  ----                 -------
  Normal  Scheduled  14m   default-scheduler    Successfully assigned default/nginx to k8s-node01
  Normal  Pulling    14m   kubelet, k8s-node01  Pulling image "nginx"
  Normal  Pulled     14m   kubelet, k8s-node01  Successfully pulled image "nginx"
  Normal  Created    14m   kubelet, k8s-node01  Created container nginx
  Normal  Started    14m   kubelet, k8s-node01  Started container nginx
```

11. 刪除剛創建的 Pod

kubectl delete pod nginx
kubectl delete -f yaml 文件

12. 強制刪除剛創建的 Pod

kubectl delete po nginx --grace-period=0 --force

warning: Immediate deletion does not wait for confirmation that the running resource has been terminated.  The resource may continue to run on the cluster indefinitely. 
pod "nginx" force deleted

13. 創建版本爲 1. 17. 4 的 Nginx Pod，並將其暴露在端口 80 上

kubectl run nginx --image=nginx:1. 17. 4 --restart=Never --port=80

kubectl run nginx --image=nginx:1. 17. 4 --restart=Never --port=80 --dry-run -o yaml

```
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: nginx
  name: nginx
spec:
  containers:
  - image: nginx:1. 17. 4
    name: nginx
    ports:
    - containerPort: 80
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Never
status: {}
```

14. 將剛創建的容器的鏡像更改爲 1. 15-alpine，並驗證該鏡像是否已更新

kubectl set image pod/nginx nginx=nginx:1. 15-alpine

kubectl edit po nginx

kubectl get po nginx -w

15. 對於剛剛更新的 Pod，將鏡像版本改回 1. 17. 1，並觀察變化

kubectl set image pod/nginx nginx=nginx:1. 17. 1

kubectl edit po nginx

kubectl get po nginx -w

16. 在不用 describe 命令的情況下檢查鏡像版本

kubectl get po nginx -o=jsonpath='{. spec. containers[]. image}{"\n"}'

17. 創建 Nginx Pod 並在 Pod 上執行簡單的 shell

kubectl run nginx --image=nginx --restart=Never
kubectl exec -it nginx /bin/bash

18. 獲取剛剛創建的 Pod 的 IP 地址

kubectl get po nginx -o wide

19. 創建一個 busybox Pod，在創建它時運行命令 ls 並檢查日誌

kubectl run busybox --image=busybox --restart=Never -- ls

kubectl logs busybox

```
bin
dev
etc
home
proc
root
sys
tmp
usr
var
```

20. 如果 Pod 崩潰了，請檢查 Pod 的先前日誌

kubectl logs busybox -p

21. 用命令 sleep 3600 創建一個 busybox Pod

kubectl run busybox --image=busybox --restart=Never -- /bin/sh -c "sleep 3600"

22. 檢查 busybox Pod 中 Nginx Pod 的連接

kubectl get pod nginx -o wide

kubectl exec -it busybox -- wget -o- 上述命令列出的 ip 地址

23. 創建一個能回顯消息“How are you”的 busybox Pod，並手動將其刪除

kubectl run busybox --image=busybox --restart=Never -it -- echo "How are you"
kubectl delete po busybox

24. 創建一個 Nginx Pod 並列出具有不同複雜度（verbosity）的 Pod

kubectl run nginx --image=nginx --restart=Never --port=80
kubectl get po nginx --v=7
```
I0105 20:54:25.780863  118442 loader.go:375] Config loaded from file:  /home/k8s-master/.kube/config
I0105 20:54:25.790538  118442 round_trippers.go:420] GET https://192.168.17.150:6443/api/v1/namespaces/default/pods/nginx
I0105 20:54:25.790575  118442 round_trippers.go:427] Request Headers:
I0105 20:54:25.790584  118442 round_trippers.go:431]     Accept: application/json;as=Table;v=v1beta1;g=meta.k8s.io, application/json
I0105 20:54:25.790591  118442 round_trippers.go:431]     User-Agent: kubectl/v1.16.3 (linux/amd64) kubernetes/b3cbbae
I0105 20:54:25.797321  118442 round_trippers.go:446] Response Status: 200 OK in 6 milliseconds
NAME    READY   STATUS    RESTARTS   AGE
nginx   1/1     Running   3          91m

```

25. 使用自定義列 PODNAME 和 PODSTATUS 列出 Nginx Pod

kubectl get po nginx -o=custom-columns="POD_NAME:.metadata.name,POD_STATUS:.status.containerStatuses"

```
nginx      [map[containerID:docker://9ff65fc8e8771aa9bc069735a7d9bffa915737cdc8da2f491e330c9c11082ebb image:nginx:latest imageID:docker-pullable://nginx@sha256:b2d89d0a210398b4d1120b3e3a7672c16a4ba09c2c4a0395f18b9f7999b768f2 lastState:map[terminated:map[containerID:docker://ade08d0814b2073079bbad9ebf51b3a3fa2af2df4a411f99b255a78d3b669eeb exitCode:0 finishedAt:2020-01-06T03:34:31Z reason:Completed startedAt:2020-01-06T03:31:59Z]] name:nginx ready:true restartCount:3 started:true state:map[running:map[startedAt:2020-01-06T03:34:31Z]]]]
```

26. 列出所有按名稱排序的 Pod

kubectl get po --sort-by=.metadata.name

27. 列出所有按創建時間排序的 Pod

kubectl get po --sort-by=.metadata.creationTimestamp

28. 用“ls; sleep 3600;”“echo Hello World; sleep 3600;”及“echo this is the third container; sleep 3600”三個命令創建一個包含三個 busybox 容器的 Pod，並觀察其狀態

sudo vim multi-containers.yaml

apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: busybox
  name: busybox
spec:
  containers:
  - args:
    - bin/sh
    - -c
    - ls; sleep 3600
    image: busybox
    name: busybox1
    resources: {}
  - args:
    - bin/sh
    - -c
    - echo Hello World;sleep 3600
    image: busybox
    name: busybox2
    resources: {}
  - args:
    - bin/sh
    - -c
    - echo this is third containers;sleep 3600
    image: busybox
    name: busybox3
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Never
status: {}

29. 檢查剛創建的每個容器的日誌

kubectl get po

kubectl logs busybox -c busybox1
kubectl logs busybox -c busybox2
kubectl logs busybox -c busybox3

30. 檢查第二個容器 busybox2 的先前日誌（如果有）

kubectl logs busybox -c busybox2 --previous

31. 在上述容器的第三個容器 busybox3 中運行命令 ls

kubectl exec busybox -c busybox3 -- ls

32. 顯示以上容器的 metrics，將其放入 file.log 中並進行驗證

kubectl top pod busybox --containers > file.log && cat file.log

33. 用主容器 busybox 創建一個 Pod，並執行“while true; do echo ‘Hi I am from Main container’ >> /var/log/index.html; sleep 5; done”，並帶有暴露在端口 80 上的 Nginx 鏡像的 sidecar 容器。用 emptyDir Volume 將該卷安裝在 /var/log 路徑（用於 busybox）和 /usr/share/nginx/html 路徑（用於nginx容器）。驗證兩個容器都在運行。

kubectl run muilti-containers-pod --image=busybox --restart=Never --dry-run -o yaml > nulti-containers-pod.yaml

```
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: muilti-containers-pod
  name: muilti-containers-pod
spec:
  volumes: 
  - name: var-logs
    emptyDir: {}
  containers:
  - image: busybox
    command: ["/bin/sh"]
    args: ["-c", "while true; do echo 'Hi I am from Main container' >> /var/log/index.html; sleep 5; done"]
    name: main-containers
    resources: {}
    volumeMounts: 
    - name: var-logs
      mountPath: /var/log
  - image: nginx
    name: sidercar-container
    resources: {}
    ports: 
      - containerPort: 80
    volumeMounts: 
    - name: var-logs
      mountPath: /usr/share/nginx/html
  dnsPolicy: ClusterFirst
  restartPolicy: Never
status: {}
```
kubectl create -f multi-containers-pod.yaml

34. 進入兩個容器並驗證 main.txt 是否存在，並用 curl localhost 從 sidecar 容器中查詢 main. txt

kubectl exec -it muilti-containers-pod -c main-container -- sh
cat var/log/index.html
kubectl exec -it muilti-containers-pod -c sidercar-container -- sh
cat /usr/share/nginx/html/index.html

35. 獲取帶有標籤信息的 Pod

kubectl get po --show-labels

36. 創建 5 個 Nginx Pod，其中兩個標籤爲 env = prod，另外三個標籤爲 env = dev

kubectl run nginx-dev1 --image=nginx --restart=Never --labels=env=dev
kubectl run nginx-dev2 --image=nginx --restart=Never --labels=env=dev
kubectl run nginx-dev3 --image=nginx --restart=Never --labels=env=dev

kubectl run nginx-pro1 --image=nginx --restart=Never --labels=env=pro
kubectl run nginx-pro2 --image=nginx --restart=Never --labels=env=pro

37. 確認所有 Pod 都使用正確的標籤創建

kubectl get po --show-labels

```
nginx-dev1                  1/1     Running   0          2m2s    env=dev
nginx-dev2                  1/1     Running   0          63s     env=dev
nginx-dev3                  1/1     Running   0          57s     env=dev
nginx-pro1                  1/1     Running   0          52s     env=pro
nginx-pro2                  1/1     Running   0          46s     env=pro
```

38. 獲得帶有標籤 env=dev 的 Pod

kubectl get pods -l env=dev

```
nginx-dev1   1/1     Running   0          4m55s
nginx-dev2   1/1     Running   0          3m56s
nginx-dev3   1/1     Running   0          3m50s
```

39. 獲得帶標籤 env=dev 的 Pod 並輸出標籤

kubectl get pods -l env=dev --show-labels

40. 獲得帶有標籤 env=pro 的 Pod

kubectl get pods -l env=pro

```
NAME         READY   STATUS    RESTARTS   AGE
nginx-pro1   1/1     Running   0          8m25s
nginx-pro2   1/1     Running   0          8m19s
```

41. 獲得帶標籤 env=prod 的 Pod 並輸出標籤

kubectl get pods -l env=pro --show-labels

42. 獲取帶有標籤 env 的 Pod

kubectl get po -L env

43. 獲得帶標籤 env=dev、env=pro 的 Pod

kubectl get po -l 'env in (dev,pro)'

44. 獲取帶有標籤 env=dev 和 env=pro 的 Pod 並輸出標籤

kubectl get po -l 'env in (dev,pro)' --show-labels

45. 將其中一個容器的標籤更改爲 env=uat 並列出所有要驗證的容器

kubectl label pod/nginx-pro1 env=aa --overwrite
kubectl get pods --show-labels

46. 刪除剛纔創建的 Pod 標籤，並確認所有標籤均已刪除

kubectl label pod nginx-dev{1..3} env-
kubectl label pod nginx-pro{1..2} env-
kubectl get pods --show-labels

47. 爲所有 Pod 添加標籤 app = nginx 並驗證

kubectl label pod nginx-dev{1..3} app=nginx
kubectl label pod nginx-pro{1..2} app=nginx
kubectl get pods --show-labels

48. 獲取所有帶有標籤的節點（如果使用 minikube，則只會獲得主節點）

kubectl get nodes --show-labels

```
NAME         STATUS   ROLES    AGE   VERSION   LABELS
k8s-master   Ready    master   13d   v1.16.3   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-master,kubernetes.io/os=linux,node-role.kubernetes.io/master=
k8s-node01   Ready    <none>   13d   v1.16.3   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node01,kubernetes.io/os=linux
k8s-node02   Ready    <none>   13d   v1.16.3   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node02,kubernetes.io/os=linux
```

49. 標記節點（如果正在使用，則爲 minikube）nodeName = nginxnode

kubectl label node minikube nodeName=nginxnode

50. 建一個標籤爲 nginx=dev 的 Pod 並將其部署在此節點上

kubectl label node k8s-node01  nginx=dev
kubectl label node k8s-node02  nginx=pro


參考文獻
medium.com/bb-tutorials-and-thoughts/practice-enough-with-these-questions-for-the-ckad-exam

# Pod 設計、狀態持久性


52. 使用節點選擇器驗證已調度的 Pod

pod.yaml
```
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: nginx
  name: nginx
spec:
  containers:
  - image: nginx
    name: nginx
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Never
  nodeSelector: 
  nginx: dev
status: {}
```

在 50 基礎上

kubectl describe po nginx | grep Node-Selectors

```
Node-Selectors:  nginx=dev
```

  
53. 驗證我們剛剛創建的 Pod Nginx 是否具有 nginx=dev 這個標籤

kubectl describe po nginx | grep Labels

```
Labels:       run=nginx
```

54. 用 name=webapp 註釋 Pod nginx-dev.*、nginx-pro.*

kubectl annotate po nginx-dev{1..3} name=webapp
kubectl annotate po nginx-pro{1..2} name=webapp

55. 驗證已正確註釋的 Pod

kubectl describe po nginx-dev{1..3} | grep -i annotations
kubectl describe po nginx-pro{1..2} | grep -i annotations

56. 刪除 Pod 上的註釋並驗證

kubectl annotate po nginx-dev{1..3} name-
kubectl annotate po nginx-pro{1..2} name-
kubectl describe po nginx-dev{1..3} | grep -i annotations
kubectl describe po nginx-pro{1..2} | grep -i annotations

57. 刪除到目前爲止我們創建的所有 Pod

kubectl delete pod --all

58. 創建一個名爲 webapp 的 Deployment，它帶有 5 個副本的鏡像 Nginx

kubectl create deployment  webapp --image=nginx --dry-run -o yaml > webapp-deployment.yaml
更改 webapp-deployment 的 replicas 爲 5

```
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: webapp
  name: webapp
spec:
  replicas: 5
  selector:
    matchLabels:
      app: webapp
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: webapp
    spec:
      containers:
      - image: nginx
        name: nginx
        resources: {}
status: {}
```


59. 用標籤獲取我們剛剛創建的 Deployment

kubectl get deploy webapp --show-labels

```
NAME     READY   UP-TO-DATE   AVAILABLE   AGE     LABELS
webapp   5/5     5            5           3m59s   app=webapp
```

60. 導出該 Deployment 的 yaml 文件

kubectl get deploy webapp -o yaml

```
apiVersion: apps/v1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "1"
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"creationTimestamp":null,"labels":{"app":"webapp"},"name":"webapp","namespace":"default"},"spec":{"replicas":5,"selector":{"matchLabels":{"app":"webapp"}},"strategy":{},"template":{"metadata":{"creationTimestamp":null,"labels":{"app":"webapp"}},"spec":{"containers":[{"image":"nginx","name":"nginx","resources":{}}]}}},"status":{}}
  creationTimestamp: "2020-01-08T05:52:11Z"
  generation: 1
  labels:
    app: webapp
  name: webapp
  namespace: default
  resourceVersion: "30357"
  selfLink: /apis/apps/v1/namespaces/default/deployments/webapp
  uid: defb62c1-1b1d-43db-ab43-5cfe90f67d68
spec:
  progressDeadlineSeconds: 600
  replicas: 5
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: webapp
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: webapp
    spec:
      containers:
      - image: nginx
        imagePullPolicy: Always
        name: nginx
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
status:
  availableReplicas: 5
  conditions:
  - lastTransitionTime: "2020-01-08T05:52:26Z"
    lastUpdateTime: "2020-01-08T05:52:26Z"
    message: Deployment has minimum availability.
    reason: MinimumReplicasAvailable
    status: "True"
    type: Available
  - lastTransitionTime: "2020-01-08T05:52:11Z"
    lastUpdateTime: "2020-01-08T05:52:29Z"
    message: ReplicaSet "webapp-58867d7bbb" has successfully progressed.
    reason: NewReplicaSetAvailable
    status: "True"
    type: Progressing
  observedGeneration: 1
  readyReplicas: 5
  replicas: 5
  updatedReplicas: 5
```

61. 獲取該 Deployment 的 Pod

kubectl get deploy --show-labels

```
NAME               READY   UP-TO-DATE   AVAILABLE   AGE    LABELS
nginx-deployment   3/3     3            3           19h    app=nginx
webapp             5/5     5            5           7m1s   app=webapp
```
kubectl get po -l app=webapp

```
NAME                      READY   STATUS    RESTARTS   AGE
webapp-58867d7bbb-4q5nn   1/1     Running   0          7m29s
webapp-58867d7bbb-9jxc7   1/1     Running   0          7m29s
webapp-58867d7bbb-hxfv6   1/1     Running   0          7m29s
webapp-58867d7bbb-qj2nk   1/1     Running   0          7m29s
webapp-58867d7bbb-wmms4   1/1     Running   0          7m29s
```

62. 將該 Deployment 從 5 個副本擴展到 20 個副本並驗證

kubectl scale deploy webapp --replicas=20

嘗試 --replicas=1000 機器配置過低 會發生問題

kubectl get po -l app=webapp

63. 獲取該 Deployment 的 rollout 狀態

kubectl rollout status deploy webapp

64. 獲取使用該 Deployment 創建的副本集

kubectl get rs -l app=webapp

65. 獲取該 Deployment 的副本集和 Pod 的 yaml

kubectl get rs -l app=webapp -o yaml
kubectl get po -l app=webapp -o yaml

66. 刪除剛創建的 Deployment，並查看所有 Pod 是否已被刪除

kubectl delete deploy webapp
kubectl get po -l app=webapp -w


67. 使用鏡像 nginx：1.17.1 和容器端口 80 創建 webapp Deployment，並驗證鏡像版本

kubectl create deploy webapp --image=nginx:1.17.1 --dry-run -o yaml > webapp.yaml

```
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: webapp
  name: webapp
spec:
  replicas: 1
  selector:
    matchLabels:
      app: webapp
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: webapp
    spec:
      containers:
      - image: nginx:1.17.1
        name: nginx
        ports: 
        - containerPort: 80
        resources: {}
status: {}
```

68. 使用鏡像版本 1.17.4 更新 Deployment 並驗證

kubectl set image deploy/webapp nginx=nginx:1.17.4
kubectl get deploy  -o wide

```
NAME               READY   UP-TO-DATE   AVAILABLE   AGE    CONTAINERS   IMAGES         SELECTOR
nginx-deployment   3/3     3            3           20h    nginx        nginx:1.7.9    app=nginx
webapp             1/1     1            1           5m7s   nginx        nginx:1.17.4   app=webapp
```

kubectl describe deploy webapp | grep Image

```
  Image:        nginx:1.17.4
```

69. 檢查 rollout 歷史記錄，並確保更新後一切正常

kubectl rollout history deploy webapp

```
deployment.apps/webapp 
REVISION  CHANGE-CAUSE
1         <none>
2         <none>
```
kubectl get deploy webapp --show-labels
kubectl get rs -l app=webapp
kubectl get po -l app=webapp

70. 撤消之前使用版本 1.17.1 的 Deployment，並驗證鏡像是否還有老版本

kubectl rollout undo deploy webapp
kubectl rollout history deploy webapp
```
deployment.apps/webapp 
REVISION  CHANGE-CAUSE
2         <none>
3         <none>
```
kubectl describe deploy webapp | grep Image

71. 使用鏡像版本 1.16.1 更新 Deployment，並驗證鏡像、檢查 rollout 歷史記錄

kubectl set image deploy/webapp nginx=nginx:1.16.1
kubectl rollout status deploy webapp
```
Waiting for deployment "webapp" rollout to finish: 1 old replicas are pending termination...
Waiting for deployment "webapp" rollout to finish: 1 old replicas are pending termination...
deployment "webapp" successfully rolled out
```
kubectl rollout history deploy webapp

```
deployment.apps/webapp 
REVISION  CHANGE-CAUSE
2         <none>
3         <none>
4         <none>
```
```
kubectl describe deploy webapp | grep Image
  Image:        nginx:1.16.1
```

72. 將 Deployment 更新到鏡像 1.17.1 並確認一切正常

kubectl rollout undo deploy webapp --to-revision=3
kubectl rollout history deploy webapp
kubectl describe deploy webapp | grep Image

73. 使用錯誤的鏡像版本 1.100 更新 Deployment，並驗證有問題

kubectl set image deploy/webapp nginx=nginx:1.10000
kubectl rollout history deploy webapp
kubectl get pods
kubectl describe po pod名稱
Warning  Failed     2s (x2 over 52s)   kubelet, k8s-node01  Error: ImagePullBackOff

74. 撤消使用先前版本的 Deployment，並確認一切正常

kubectl rollout undo deploy webapp
kubectl rollout status deploy webapp
kubectl get pods

75. 檢查該 Deployment 的特定修訂版本的歷史記錄

kubectl rollout history deploy webapp --revision=特定版本記錄號


76. 暫停 Deployment rollout

kubectl rollout pause deploy  webapp


77. 用最新版本的鏡像更新 Deployment，並檢查歷史記錄

kubectl set image deploy/webapp nginx=nginx:lastest
kubectl rollout history deploy webapp

78. 恢復 Deployment rollout

kubectl rollout resume deploy  webapp

79. 檢查 rollout 歷史記錄，確保是最新版本

kubectl rollout history deploy webapp
kubectl rollout history deploy webapp --revision=9

80. 將自動伸縮應用到該 Deployment 中，最少副本數爲 10，最大副本數爲 20，
目標 CPU 利用率 85%，並驗證 hpa 已創建，將副本數從 1 個增加到 10 個

kubectl autoscale deploy webapp --min=10 --max=20 --cpu-percent=85
```
kubectl get hpa
NAME     REFERENCE           TARGETS         MINPODS   MAXPODS   REPLICAS   AGE
webapp   Deployment/webapp   <unknown>/85%   10        20        0          9s
```
kubectl get po -l app=webapp
```
NAME                      READY   STATUS    RESTARTS   AGE
webapp-7668577c8f-98ltc   1/1     Running   0          29s
webapp-7668577c8f-bjmhz   1/1     Running   0          29s
webapp-7668577c8f-cbl2k   1/1     Running   0          29s
webapp-7668577c8f-dnb5z   1/1     Running   0          2m54s
webapp-7668577c8f-dvfrt   1/1     Running   0          29s
webapp-7668577c8f-gcqgt   1/1     Running   0          29s
webapp-7668577c8f-ht8pg   1/1     Running   0          29s
webapp-7668577c8f-nhjzs   1/1     Running   0          29s
webapp-7668577c8f-nsmqd   1/1     Running   0          29s
webapp-7668577c8f-rjg58   1/1     Running   0          29s
```

81. 通過刪除剛剛創建的 Deployment 和 hpa 來清理集羣

kubectl delete deploy webapp
kubectl delete hpa webapp

82. 用鏡像 node 創建一個 Job，並驗證是否有對應的 Pod 創建

kubectl create job nodeversion --image=node -- node v
kubectl get job -w
kubectl get pod

83. 獲取剛剛創建的 Job 的日誌

kubectl logs pod 名稱

84. 用鏡像 busybox 輸出 Job 的 yaml 文件，並回顯“Hello I am from job”

kubectl create job hello-job --image=busybox --dry-run -o yaml -- echo "Hello I am from job"

```
apiVersion: batch/v1
kind: Job
metadata:
  creationTimestamp: null
  name: hello-job
spec:
  template:
    metadata:
      creationTimestamp: null
    spec:
      containers:
      - command:
        - echo
        - Hello I am from job
        image: busybox
        name: hello-job
        resources: {}
      restartPolicy: Never
status: {}
```

85. 將上面的 yaml 文件複製到 hello-job.yaml 文件並創建 Job

kubectl create job hello-job --image=busybox --dry-run -o yaml -- echo "Hello I am from job" > hello-job.yaml

kubectl apply -f hello-job.yaml

86. 驗證 Job 並創建關聯的容器，檢查日誌

kubectl get pod
kubectl get po
 kubectl logs po 名稱

87. 刪除我們剛剛創建的 Job

kubectl delete job hello-job

88. 創建一個相同的 Job，並使它一個接一個地運行 10 次

kubectl create job hello-job --image=busybox --dry-run -o yaml -- echo "Hello I am from job" > 10-job.yaml

在 10-job.yaml 添加 completions: 10
```
apiVersion: batch/v1
kind: Job
metadata:
  creationTimestamp: null
  name: hello-job
spec:
  completions: 10
  template:
    metadata:
      creationTimestamp: null
    spec:
      containers:
      - command:
        - echo
        - Hello I am from Job
        image: busybox
        name: hello-job
        resources: {}
      restartPolicy: Never
status: {}
```
kubectl get job -w
kubectl get po
```
NAME          COMPLETIONS   DURATION   AGE
hello-job     9/10          53s        53s
nodeversion   1/1           3m14s      18m
hello-job     10/10         59s        59s
```


89. 運行 10 次，確認已創建 10 個 Pod，並在完成後刪除它們

kubectl delete job hello-job

90. 創建相同的 Job 並使它並行運行 10 次

kubectl create job hello-job --image=busybox --dry-run -o yaml -- echo "Hello I am from job" > 10-parallelism-job.yaml

```
apiVersion: batch/v1
kind: Job
metadata:
  creationTimestamp: null
  name: hello-job
spec:
  parallelism: 10
  template:
    metadata:
      creationTimestamp: null
    spec:
      containers:
      - command:
        - echo
        - Hello I am from Job
        image: busybox
        name: hello-job
        resources: {}
      restartPolicy: Never
status: {}
```

91. 並行運行 10 次，確認已創建 10 個 Pod，並在完成後將其刪除

kubectl get job -w
kubectl get po


92. 創建一個帶有 busybox 鏡像的 Cronjob，每分鐘打印一次來自 Kubernetes 集羣消息的日期和 hello

kubectl create cronjob date-job --image=busybox --schedule="*/1 * * * *" -- bin/sh -c "date; echo Hello from kubernetes cluster"

kubectl get cronjob

kubectl get po

kubectl logs pod 名稱

93. 輸出上述 cronjob 的 yaml 文件

kubectl get cj date-job -o yaml

```
apiVersion: batch/v1beta1
kind: CronJob
metadata:
  creationTimestamp: "2020-01-08T08:50:52Z"
  name: date-job
  namespace: default
  resourceVersion: "50543"
  selfLink: /apis/batch/v1beta1/namespaces/default/cronjobs/date-job
  uid: 22d49b8d-58ec-468a-b589-d5f60f0030c0
spec:
  concurrencyPolicy: Allow
  failedJobsHistoryLimit: 1
  jobTemplate:
    metadata:
      creationTimestamp: null
      name: date-job
    spec:
      template:
        metadata:
          creationTimestamp: null
        spec:
          containers:
          - command:
            - bin/sh
            - -c
            - date; echo Hello from kubernetes cluster
            image: busybox
            imagePullPolicy: Always
            name: date-job
            resources: {}
            terminationMessagePath: /dev/termination-log
            terminationMessagePolicy: File
          dnsPolicy: ClusterFirst
          restartPolicy: OnFailure
          schedulerName: default-scheduler
          securityContext: {}
          terminationGracePeriodSeconds: 30
  schedule: '*/1 * * * *'
  successfulJobsHistoryLimit: 3
  suspend: false
status:
  lastScheduleTime: "2020-01-08T08:51:00Z"
```

94. 驗證 cronJob 爲每分鐘運行創建一個單獨的 Job 和 Pod，並驗證 Pod 的日誌

kubectl get job
kubectl get po
kubectl logs date-job-<jobid>-<pod>

95. 刪除 cronJob，並驗證所有關聯的 Job 和 Pod 也都被刪除

kubectl delete cj date-job
// verify pods and jobs
kubectl get po
kubectl get job

96. 列出集羣中的持久卷

kubectl get pv

97. 創建一個名爲 task-pv-volume 的 PersistentVolume，其 storgeClassName 爲 manual，storage 爲 10Gi，accessModes 爲 ReadWriteOnce，hostPath 爲 /mnt/data

task-pv-volume.yaml

```
apiVersion: v1
kind: PersistentVolume
metadata:
  name: task-pv-volume
  labels: 
    type: local
spec:
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  storageClassName: manual
  hostPath: 
    path: "/mnt/data"
```
kubectl get pv

```
NAME             CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   REASON   AGE
task-pv-volume   10Gi       RWO            Retain           Available           manual                  88s
```



98. 創建一個存儲至少 3Gi、訪問模式爲 ReadWriteOnce 的 PersistentVolumeClaim，並確認它的狀態是否是綁定的

kubectl create -f task-pv-claim.yaml
kubectl get pvc

```
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: task-pv-claim
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 3Gi
  storageClassName: manual
```

99. 刪除我們剛剛創建的持久卷和 PersistentVolumeClaim

kubectl delete pvc task-pv-claim
kubectl delete pv task-pv-volume

100. 使用鏡像 Redis 創建 Pod，並配置一個在 Pod 生命週期內可持續使用的卷

redis-storage.yaml
```
apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
  - name: redis
    image: redis
    volumeMounts:
    - name: redis-storage
      mountPath: /data/redis
  volumes:
  - name: redis-storage
    emptyDir: {}
```

101. 在上面的 Pod 中執行操作，並在 /data/redis 路徑中創建一個名爲 file.txt 的文件，其文本爲“This is the file”，然後打開另一個選項卡，再次使用同一 Pod 執行，並驗證文件是否在同一路徑中

kubectl exec -it redis /bin/sh

cd /data/redis

echo "This is the file" > file.txt

102. 刪除上面的 Pod，然後從相同的 yaml 文件再次創建，並驗證路徑 /data/redis 中是否沒有 file.txt

kubectl delete po redis

kubectl apply -f redis-storage.yaml

kubectl exec -it redis /bin/sh

cat /data/redis/file.txt
cat: /data/redis/file.txt: No such file or directory

103. 創建一個名爲 task-pv-volume 的 PersistentVolume，其 storgeClassName 爲 manual，storage 爲 10Gi，accessModes 爲 ReadWriteOnce，hostPath 爲 /mnt/data；並創建一個存儲至少 3Gi、訪問模式爲 ReadWriteOnce 的 PersistentVolumeClaim，並確認它的狀態是否是綁定的

kubectl create -f task-pv-volume.yaml
kubectl create -f task-pv-claim.yaml
kubectl get pv
kubectl get pvc

配置如下所述：
task-pv-volume.yaml
```
apiVersion: v1
kind: PersistentVolume
metadata:
  name: task-pv-volume
  labels: 
    type: local
spec:
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  storageClassName: manual
  hostPath: 
    path: "/mnt/data"
```
task-pv-claim.yaml
```
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: task-pv-claim
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 3Gi
  storageClassName: manual
```


104. 用容器端口 80 和 PersistentVolumeClaim task-pv-claim 創建一個 Nginx 容器，且具有路徑“/usr/share/nginx/html”

task-pv-pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: task-pv-pod
spec:
  containers:
    - name: task-pv-container
      image: nginx
      ports:
        - containerPort: 80
          name: "http-server"
      volumeMounts:
      - mountPath: "/usr/share/nginx/html"
        name: task-pv-storage
  volumes:
    - name: task-pv-storage
      persistentVolumeClaim:
        claimName: task-pv-claim

kubectl get pv
NAME             CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                   STORAGECLASS   REASON   AGE
task-pv-volume   10Gi       RWO            Retain           Bound    default/task-pv-claim   manual                  85m

kubectl get pvc
NAME            STATUS   VOLUME           CAPACITY   ACCESS MODES   STORAGECLASS   AGE
task-pv-claim   Bound    task-pv-volume   10Gi       RWO            manual         10m

待完善

參考文獻
https://medium.com/bb-tutorials-and-thoughts/practice-enough-with-these-questions-for-the-ckad-exam-2f42d1228552