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

  • 创建一个 app
  • 查看 app 状态
  • 更新 app
  • 回滚 app
  • 扩缩容 app
  • 删除 app
创建一个 app

  • 通过 yaml 配置文件来定义 Deployment

    • 关于 apiVersion 的写法，请参考：
    • https://github.com/kubernetes/kubernetes/blob/630dbedef9de9ef678f16132796b103b8a03fcda/pkg/api/testing/defaulting_test.go
    • 关于 metadata 中的 name
    • 定义来 deployment 的名称
    • 同一个 namespace 下名称不能重复
    • 关于 metadata 中的 labels
    • k/v 键值对
    • key 的命名规则
      • 必须
      • 包含一个可选的 prefix 和 name 并小于 64 字符
      • name 以字母和数字 [a-z0-9A-Z] 开头和结尾，中间可以是 dashes (-)，underscores (_)，dots (.)，字母和数字
      • prefix 是可选的，类似这样："kubernetes.io/" 暂不讨论
    • Value 的命名规则
      • 可以为空，或小于 64 字符
      • 以字母和数字 [a-z0-9A-Z] 开头和结尾，中间可以是 dashes (-)，underscores (_)，dots (.)，字母和数字
    • 关于 metadata 中的 namespace
    • 默认使用 default 
      [[email protected] ~]# 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
  • 运行 app 
    ### 注意：使用 --record 可以记录指令的 history 便于后续 rolling update 选择
[[email protected] ~]# kubectl apply -f ~/k8s_install/test/whoami/app.yaml --record
deployment "test-deployment-app-whoami" created
查看 app 状态
  • 查看信息 
    [[email protected] ~]# kubectl get deployments
NAME                         DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
test-deployment-app-whoami   3         3         3            3           5m
[[email protected] ~]# kubectl get rs
NAME                                    DESIRED   CURRENT   READY     AGE
test-deployment-app-whoami-6cf9cd6bf4   3         3         3         5m
[[email protected] ~]# 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
[[email protected] ~]# 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
  • 试着更新 1 次镜像后，查看信息，重点留意版本历史 
    
### 更新 image 为其他版本：
[[email protected] ~]# kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.7
deployment "test-deployment-app-whoami" image updated

查看信息

[[email protected] ~]# kubectl rollout status deployments/test-deployment-app-whoami
deployment "test-deployment-app-whoami" successfully rolled out
[[email protected] ~]# kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
test-deployment-app-whoami 3 3 3 3 11m
[[email protected] ~]# 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
[[email protected] ~]# 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

[[email protected] ~]# 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

[[email protected] ~]# 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 次镜像后，再次查看信息
```bash
[[email protected] ~]# kubectl set image deployments/test-deployment-app-whoami whoami=opera443399/whoami:0.8
deployment "test-deployment-app-whoami" image updated
[[email protected] ~]# kubectl rollout status deployments/test-deployment-app-whoami
deployment "test-deployment-app-whoami" successfully rolled out
[[email protected] ~]# kubectl get deployments
NAME                         DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
test-deployment-app-whoami   3         3         3            3           17m
[[email protected] ~]# 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
[[email protected] ~]# 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
[[email protected] ~]# 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
[[email protected] ~]# 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

### 符合预期，我们现在有了 3 个版本
回滚 app
  • 回滚到上一个版本 
    
[[email protected] ~]# kubectl rollout undo deployments/test-deployment-app-whoami
deployment "test-deployment-app-whoami"
[[email protected] ~]# 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

[[email protected] ~]# 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

[[email protected] ~]# 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


- 回滚到指定的版本
```bash
[[email protected] ~]# kubectl rollout undo deployments/test-deployment-app-whoami --to-revision=1
deployment "test-deployment-app-whoami"
[[email protected] ~]# 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

[[email protected] ~]# 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

[[email protected] ~]# 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
扩缩容 app
  • 扩容 
    
### 调整副本数量到 10 个
[[email protected] ~]# kubectl scale deployments/test-deployment-app-whoami --replicas=10
deployment "test-deployment-app-whoami" scaled

查看信息

[[email protected] ~]# kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
test-deployment-app-whoami 10 10 10 10 39m
[[email protected] ~]# 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
[[email protected] ~]# 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


- 缩容
```bash
### 调整副本数量到 5 个
[[email protected] ~]# kubectl scale deployments/test-deployment-app-whoami --replicas=5
deployment "test-deployment-app-whoami" scaled

### 查看信息
[[email protected] ~]# kubectl get deployments
NAME                         DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
test-deployment-app-whoami   5         5         5            5           41m
[[email protected] ~]# 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
[[email protected] ~]# 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
删除
[[email protected] test]# kubectl delete deployments/test-deployment-app-whoami
deployment "test-deployment-app-whoami" deleted
[[email protected] test]# kubectl get deployments
No resources found.

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