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k8s基本概念-如何使用Deployments

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k8s基本概念-如何使用Deployments

2018/1/5

Deployments 使用示例

  • 創建一個 app
  • 查看 app 狀態
  • 更新 app
  • 回滾 app
  • 擴縮容 app
  • 刪除 app
創建一個 app
  • 通過 yaml 配置文件來定義 Deployment

    • 關於 apiVersion 的寫法,請參考:
    • https://github.com/kubernetes/kubernetes/blob/630dbedef9de9ef678f16132796b103b8a03fcda/pkg/api/testing/defaulting_test.go
    • 關於 metadata 中的 name
    • 定義來 deployment 的名稱
    • 同一個 namespace 下名稱不能重復
    • 關於 metadata 中的 labels
    • k/v 鍵值對
    • key 的命名規則
      • 必須
      • 包含一個可選的 prefix 和 name 並小於 64 字符
      • name 以字母和數字 [a-z0-9A-Z] 開頭和結尾,中間可以是 dashes (-),underscores (_),dots (.),字母和數字
      • prefix 是可選的,類似這樣:"kubernetes.io/" 暫不討論
    • Value 的命名規則
      • 可以為空,或小於 64 字符
      • 以字母和數字 [a-z0-9A-Z] 開頭和結尾,中間可以是 dashes (-),underscores (_),dots (.),字母和數字
    • 關於 metadata 中的 namespace
    • 默認使用 default
      [root@tvm-00 ~]# cat ~/k8s_install/test/whoami/app.yaml
      apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
      kind: Deployment
      metadata:
      name: test-deployment-app-whoami
      labels:
      app: whoami
      spec:
      replicas: 3
      selector:
      matchLabels:
      app: whoami
      template:
      metadata:
      labels:
      app: whoami
      spec:
      containers:
      - name: whoami
        image: opera443399/whoami:0.9
        ports:
          - containerPort: 80
  • 運行 app
    ### 註意:使用 --record 可以記錄指令的 history 便於後續 rolling update 選擇
    [root@tvm-00 ~]# kubectl apply -f ~/k8s_install/test/whoami/app.yaml --record
    deployment "test-deployment-app-whoami" created
查看 app 狀態
  • 查看信息
    [root@tvm-00 ~]# kubectl get deployments
    NAME                         DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
    test-deployment-app-whoami   3         3         3            3           5m
    [root@tvm-00 ~]# kubectl get rs
    NAME                                    DESIRED   CURRENT   READY     AGE
    test-deployment-app-whoami-6cf9cd6bf4   3         3         3         5m
    [root@tvm-00 ~]# kubectl get pods
    NAME                                          READY     STATUS    RESTARTS   AGE
    test-deployment-app-whoami-6cf9cd6bf4-59h9x   1/1       Running   0          5m
    test-deployment-app-whoami-6cf9cd6bf4-978ht   1/1       Running   0          5m
    test-deployment-app-whoami-6cf9cd6bf4-w5dhk   1/1       Running   0          5m
    [root@tvm-00 ~]# kubectl get pods --show-labels
    NAME                                          READY     STATUS    RESTARTS   AGE       LABELS
    test-deployment-app-whoami-6cf9cd6bf4-59h9x   1/1       Running   0          7m        app=whoami,pod-template-hash=2795782690
    test-deployment-app-whoami-6cf9cd6bf4-978ht   1/1       Running   0          7m        app=whoami,pod-template-hash=2795782690
    test-deployment-app-whoami-6cf9cd6bf4-w5dhk   1/1       Running   0          7m        app=whoami,pod-template-hash=2795782690
更新 app
  • 試著更新 1 次鏡像後,查看信息,重點留意版本歷史
    
    ### 更新 image 為其他版本:
    [root@tvm-00 ~]# kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7
    deployment "test-deployment-app-whoami" image updated

查看信息

[root@tvm-00 ~]# kubectl rollout status deployments/test-deployment-app-whoami
deployment "test-deployment-app-whoami" successfully rolled out
[root@tvm-00 ~]# kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
test-deployment-app-whoami 3 3 3 3 11m
[root@tvm-00 ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
test-deployment-app-whoami-68c6cd964 3 3 3 42s
test-deployment-app-whoami-6cf9cd6bf4 0 0 0 11m
[root@tvm-00 ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
test-deployment-app-whoami-68c6cd964-bfznh 1/1 Running 0 54s
test-deployment-app-whoami-68c6cd964-r7vp5 1/1 Running 0 56s
test-deployment-app-whoami-68c6cd964-vssrj 1/1 Running 0 53s

[root@tvm-00 ~]# kubectl describe deployments/test-deployment-app-whoami
Name: test-deployment-app-whoami
Namespace: default
CreationTimestamp: Wed, 27 Dec 2017 17:44:30 +0800
Labels: app=whoami
Annotations: deployment.kubernetes.io/revision=2
kubectl.kubernetes.io/last-applied-configuration=(略)
kubernetes.io/change-cause=kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7
Selector: app=whoami
Replicas: 3 desired
3 updated 3 total 3 available 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 25% max unavailable, 25% max surge
Pod Template:
Labels: app=whoami
Containers:
whoami:
Image: opera443399/whoami:0.7
Port: 80/TCP
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason

Available True MinimumReplicasAvailable
Progressing True NewReplicaSetAvailable
OldReplicaSets: <none>
NewReplicaSet: test-deployment-app-whoami-68c6cd964 (3/3 replicas created)
Events:
Type Reason Age From Message


Normal ScalingReplicaSet 12m deployment-controller Scaled up replica set test-deployment-app-whoami-6cf9cd6bf4 to 3
Normal ScalingReplicaSet 1m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 1
Normal ScalingReplicaSet 1m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 2
Normal ScalingReplicaSet 1m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 2
Normal ScalingReplicaSet 1m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 1
Normal ScalingReplicaSet 1m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 3
Normal ScalingReplicaSet 1m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 0

[root@tvm-00 ~]# kubectl rollout history deployments/test-deployment-app-whoami
deployments "test-deployment-app-whoami"
REVISION CHANGE-CAUSE
1 kubectl apply --filename=/root/k8s_install/test/whoami/app.yaml --record=true
2 kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7


- 再更新 1 次鏡像後,再次查看信息
```bash
[root@tvm-00 ~]# kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.8
deployment "test-deployment-app-whoami" image updated
[root@tvm-00 ~]# kubectl rollout status deployments/test-deployment-app-whoami
deployment "test-deployment-app-whoami" successfully rolled out
[root@tvm-00 ~]# kubectl get deployments
NAME                         DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
test-deployment-app-whoami   3         3         3            3           17m
[root@tvm-00 ~]# kubectl get rs
NAME                                    DESIRED   CURRENT   READY     AGE
test-deployment-app-whoami-68b94dd7bf   3         3         3         46s
test-deployment-app-whoami-68c6cd964    0         0         0         6m
test-deployment-app-whoami-6cf9cd6bf4   0         0         0         17m
[root@tvm-00 ~]# kubectl get pods
NAME                                          READY     STATUS    RESTARTS   AGE
test-deployment-app-whoami-68b94dd7bf-5g89x   1/1       Running   0          45s
test-deployment-app-whoami-68b94dd7bf-75xjd   1/1       Running   0          52s
test-deployment-app-whoami-68b94dd7bf-pchpw   1/1       Running   0          49s
[root@tvm-00 ~]# kubectl describe deployments/test-deployment-app-whoami
Name:                   test-deployment-app-whoami
Namespace:              default
CreationTimestamp:      Wed, 27 Dec 2017 17:44:30 +0800
Labels:                 app=whoami
Annotations:            deployment.kubernetes.io/revision=3
                        kubectl.kubernetes.io/last-applied-configuration=(略)
                        kubernetes.io/change-cause=kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.8
Selector:               app=whoami
Replicas:               3 desired | 3 updated | 3 total | 3 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  25% max unavailable, 25% max surge
Pod Template:
  Labels:  app=whoami
  Containers:
   whoami:
    Image:        opera443399/whoami:0.8
    Port:         80/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  <none>
NewReplicaSet:   test-deployment-app-whoami-68b94dd7bf (3/3 replicas created)
Events:
  Type    Reason             Age              From                   Message
  ----    ------             ----             ----                   -------
  Normal  ScalingReplicaSet  18m              deployment-controller  Scaled up replica set test-deployment-app-whoami-6cf9cd6bf4 to 3
  Normal  ScalingReplicaSet  7m               deployment-controller  Scaled up replica set test-deployment-app-whoami-68c6cd964 to 1
  Normal  ScalingReplicaSet  7m               deployment-controller  Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 2
  Normal  ScalingReplicaSet  7m               deployment-controller  Scaled up replica set test-deployment-app-whoami-68c6cd964 to 2
  Normal  ScalingReplicaSet  7m               deployment-controller  Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 1
  Normal  ScalingReplicaSet  7m               deployment-controller  Scaled up replica set test-deployment-app-whoami-68c6cd964 to 3
  Normal  ScalingReplicaSet  7m               deployment-controller  Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 0
  Normal  ScalingReplicaSet  2m               deployment-controller  Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 1
  Normal  ScalingReplicaSet  2m               deployment-controller  Scaled down replica set test-deployment-app-whoami-68c6cd964 to 2
  Normal  ScalingReplicaSet  2m               deployment-controller  Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 2
  Normal  ScalingReplicaSet  2m (x3 over 2m)  deployment-controller  (combined from similar events): Scaled down replica set test-deployment-app-whoami-68c6cd964 to 0
[root@tvm-00 ~]# kubectl rollout history deployments/test-deployment-app-whoami
deployments "test-deployment-app-whoami"
REVISION  CHANGE-CAUSE
1         kubectl apply --filename=/root/k8s_install/test/whoami/app.yaml --record=true
2         kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7
3         kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.8

### 符合預期,我們現在有了 3 個版本
回滾 app
  • 回滾到上一個版本
    
    [root@tvm-00 ~]# kubectl rollout undo deployments/test-deployment-app-whoami
    deployment "test-deployment-app-whoami"
    [root@tvm-00 ~]# kubectl rollout history deployments/test-deployment-app-whoami
    deployments "test-deployment-app-whoami"
    REVISION  CHANGE-CAUSE
    1         kubectl apply --filename=/root/k8s_install/test/whoami/app.yaml --record=true
    3         kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.8
    4         kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7

[root@tvm-00 ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
test-deployment-app-whoami-68b94dd7bf 0 0 0 16m
test-deployment-app-whoami-68c6cd964 3 3 3 22m
test-deployment-app-whoami-6cf9cd6bf4 0 0 0 33m

[root@tvm-00 ~]# kubectl describe deployments/test-deployment-app-whoami
Name: test-deployment-app-whoami
Namespace: default
CreationTimestamp: Wed, 27 Dec 2017 17:44:30 +0800
Labels: app=whoami
Annotations: deployment.kubernetes.io/revision=4
kubectl.kubernetes.io/last-applied-configuration=(略)
kubernetes.io/change-cause=kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7
Selector: app=whoami
Replicas: 3 desired
3 updated 3 total 3 available 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 25% max unavailable, 25% max surge
Pod Template:
Labels: app=whoami
Containers:
whoami:
Image: opera443399/whoami:0.7
Port: 80/TCP
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason

Available True MinimumReplicasAvailable
Progressing True NewReplicaSetAvailable
OldReplicaSets: <none>
NewReplicaSet: test-deployment-app-whoami-68c6cd964 (3/3 replicas created)
Events:
Type Reason Age From Message


Normal ScalingReplicaSet 27m deployment-controller Scaled up replica set test-deployment-app-whoami-6cf9cd6bf4 to 3
Normal ScalingReplicaSet 17m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 2
Normal ScalingReplicaSet 17m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 2
Normal ScalingReplicaSet 17m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 1
Normal ScalingReplicaSet 17m deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 3
Normal ScalingReplicaSet 16m deployment-controller Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 0
Normal ScalingReplicaSet 11m deployment-controller Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 1
Normal ScalingReplicaSet 11m deployment-controller Scaled down replica set test-deployment-app-whoami-68c6cd964 to 2
Normal ScalingReplicaSet 11m deployment-controller Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 2
Normal ScalingReplicaSet 1m (x2 over 17m) deployment-controller Scaled up replica set test-deployment-app-whoami-68c6cd964 to 1
Normal DeploymentRollback 1m deployment-controller Rolled back deployment "test-deployment-app-whoami" to revision 2
Normal ScalingReplicaSet 1m (x8 over 11m) deployment-controller (combined from similar events): Scaled down replica set test-deployment-app-whoami-68b94dd7bf to 0


- 回滾到指定的版本
```bash
[root@tvm-00 ~]# kubectl rollout undo deployments/test-deployment-app-whoami --to-revision=1
deployment "test-deployment-app-whoami"
[root@tvm-00 ~]# kubectl rollout history deployments/test-deployment-app-whoami
deployments "test-deployment-app-whoami"
REVISION  CHANGE-CAUSE
3         kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.8
4         kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7
5         kubectl apply --filename=/root/k8s_install/test/whoami/app.yaml --record=true

[root@tvm-00 ~]# kubectl get rs
NAME                                    DESIRED   CURRENT   READY     AGE
test-deployment-app-whoami-68b94dd7bf   0         0         0         16m
test-deployment-app-whoami-68c6cd964    0         0         0         22m
test-deployment-app-whoami-6cf9cd6bf4   3         3         3         33m

[root@tvm-00 ~]# kubectl describe deployments/test-deployment-app-whoami
Name:                   test-deployment-app-whoami
Namespace:              default
CreationTimestamp:      Wed, 27 Dec 2017 17:44:30 +0800
Labels:                 app=whoami
Annotations:            deployment.kubernetes.io/revision=5
                        kubectl.kubernetes.io/last-applied-configuration=(略)
                        kubernetes.io/change-cause=kubectl apply --filename=/root/k8s_install/test/whoami/app.yaml --record=true
Selector:               app=whoami
Replicas:               3 desired | 3 updated | 3 total | 3 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  25% max unavailable, 25% max surge
Pod Template:
  Labels:  app=whoami
  Containers:
   whoami:
    Image:        opera443399/whoami:0.9
    Port:         80/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  <none>
NewReplicaSet:   test-deployment-app-whoami-6cf9cd6bf4 (3/3 replicas created)
Events:
  Type    Reason              Age                 From                   Message
  ----    ------              ----                ----                   -------
  Normal  ScalingReplicaSet   29m                 deployment-controller  Scaled up replica set test-deployment-app-whoami-6cf9cd6bf4 to 3
  Normal  ScalingReplicaSet   19m                 deployment-controller  Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 2
  Normal  ScalingReplicaSet   19m                 deployment-controller  Scaled up replica set test-deployment-app-whoami-68c6cd964 to 2
  Normal  ScalingReplicaSet   19m                 deployment-controller  Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 1
  Normal  ScalingReplicaSet   19m                 deployment-controller  Scaled up replica set test-deployment-app-whoami-68c6cd964 to 3
  Normal  ScalingReplicaSet   19m                 deployment-controller  Scaled down replica set test-deployment-app-whoami-6cf9cd6bf4 to 0
  Normal  ScalingReplicaSet   13m                 deployment-controller  Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 1
  Normal  ScalingReplicaSet   13m                 deployment-controller  Scaled down replica set test-deployment-app-whoami-68c6cd964 to 2
  Normal  ScalingReplicaSet   13m                 deployment-controller  Scaled up replica set test-deployment-app-whoami-68b94dd7bf to 2
  Normal  ScalingReplicaSet   3m (x2 over 19m)    deployment-controller  Scaled up replica set test-deployment-app-whoami-68c6cd964 to 1
  Normal  DeploymentRollback  3m                  deployment-controller  Rolled back deployment "test-deployment-app-whoami" to revision 2
  Normal  DeploymentRollback  29s                 deployment-controller  Rolled back deployment "test-deployment-app-whoami" to revision 1
  Normal  ScalingReplicaSet   27s (x12 over 13m)  deployment-controller  (combined from similar events): Scaled up replica set test-deployment-app-whoami-6cf9cd6bf4 to 3
  Normal  ScalingReplicaSet   27s                 deployment-controller  Scaled down replica set test-deployment-app-whoami-68c6cd964 to 1
  Normal  ScalingReplicaSet   26s                 deployment-controller  Scaled down replica set test-deployment-app-whoami-68c6cd964 to 0
擴縮容 app
  • 擴容
    
    ### 調整副本數量到 10 個
    [root@tvm-00 ~]# kubectl scale deployments/test-deployment-app-whoami --replicas=10
    deployment "test-deployment-app-whoami" scaled

查看信息

[root@tvm-00 ~]# kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
test-deployment-app-whoami 10 10 10 10 39m
[root@tvm-00 ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
test-deployment-app-whoami-68b94dd7bf 0 0 0 23m
test-deployment-app-whoami-68c6cd964 0 0 0 29m
test-deployment-app-whoami-6cf9cd6bf4 10 10 10 39m
[root@tvm-00 ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
test-deployment-app-whoami-6cf9cd6bf4-2dd5m 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-4nx7x 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-bb7v7 1/1 Running 0 10m
test-deployment-app-whoami-6cf9cd6bf4-c7cht 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-dph22 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-jhtqz 1/1 Running 0 10m
test-deployment-app-whoami-6cf9cd6bf4-jjfp5 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-nlqq5 1/1 Running 0 36s
test-deployment-app-whoami-6cf9cd6bf4-px24h 1/1 Running 0 10m
test-deployment-app-whoami-6cf9cd6bf4-rldhd 1/1 Running 0 36s


- 縮容
```bash
### 調整副本數量到 5 個
[root@tvm-00 ~]# kubectl scale deployments/test-deployment-app-whoami --replicas=5
deployment "test-deployment-app-whoami" scaled

### 查看信息
[root@tvm-00 ~]# kubectl get deployments
NAME                         DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
test-deployment-app-whoami   5         5         5            5           41m
[root@tvm-00 ~]# kubectl get rs
NAME                                    DESIRED   CURRENT   READY     AGE
test-deployment-app-whoami-68b94dd7bf   0         0         0         25m
test-deployment-app-whoami-68c6cd964    0         0         0         30m
test-deployment-app-whoami-6cf9cd6bf4   5         5         5         41m
[root@tvm-00 ~]# kubectl get pods
NAME                                          READY     STATUS    RESTARTS   AGE
test-deployment-app-whoami-6cf9cd6bf4-2dd5m   1/1       Running   0          2m
test-deployment-app-whoami-6cf9cd6bf4-bb7v7   1/1       Running   0          12m
test-deployment-app-whoami-6cf9cd6bf4-c7cht   1/1       Running   0          2m
test-deployment-app-whoami-6cf9cd6bf4-jhtqz   1/1       Running   0          12m
test-deployment-app-whoami-6cf9cd6bf4-px24h   1/1       Running   0          12m
刪除
[root@tvm-00 test]# kubectl delete deployments/test-deployment-app-whoami
deployment "test-deployment-app-whoami" deleted
[root@tvm-00 test]# kubectl get deployments
No resources found.

k8s基本概念-如何使用Deployments