kubernetes资源对象Deployment

最新推荐文章于 2024-11-08 20:02:54 发布

TongLe0623

最新推荐文章于 2024-11-08 20:02:54 发布

阅读量786

点赞数

分类专栏： kubernetes

本文链接：https://blog.youkuaiyun.com/qq_16538827/article/details/119816660

版权

kubernetes 专栏收录该内容

28 篇文章

订阅专栏

Deployment 是什么？

Deployment 为 Pod 和 Replica Set（下一代 Replication Controller）提供声明式更新。你只需要在 Deployment 中描述你想要的目标状态是什么，Deployment controller 就会帮你将 Pod Replica Set 的实际状态改变到你的目标状态。你可以定义一个全新的Deployment，也可以创建一个新的替换旧的 Deployment。

一个典型的用例如下：

使用 Deployment 来创建 ReplicaSet。ReplicaSet 在后台创建 pod。检查启动状态，看它是成功还是失败。
然后，通过更新 Deployment 的 PodTemplateSpec 字段来声明 Pod 的新状态。这会创建一个新的 ReplicaSet，Deployment 会按照控制的速率将 pod 从旧的ReplicaSet 移动到新的 ReplicaSet 中。
如果当前状态不稳定，回滚到之前的 Deployment revision。每次回滚都会更新Deployment 的 revision。扩容 Deployment 以满足更高的负载。
暂停 Deployment 来应用 PodTemplateSpec 的多个修复，然后恢复上线。
根据 Deployment 的状态判断上线是否 hang 住了。
清除旧的不必要的 ReplicaSet。

Deployment 为 Pod 和 ReplicaSet 提供了一个声明式定义 (declarative) 方法，用来替代以前的 ReplicationController 来方便的管理应用。

简单的Nginx.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: 3 #3个副本
  template:
    metadata:
      lables:
        app: nginx
    spec:
      containers:
      - name: nginx
        image:nginx:1.8
        ports:
        - containerPort: 80

扩容、修改副本数量：

kubectl scale deployment nginx-deployment --replicas 10

如果集群支持 horizontal pod autoscaling 的话，还可以为 Deployment 设置自动扩展：

kubectl autoscale deployment nginx-deployment --min=10 --max=15 --cpu
-percent=80

更新镜像：

kubectl set image deployment/nginx-deployment nginx=nginx:1.9.1

回滚：

kubectl rollout undo deployment/nginx-deployment

创建Deployment示例：

kubectl create -f tomcat-deployment.yaml --record #创建deployment
deployment "nginx-deployment" created

[root@master yaml]# kubectl get deployments      #查看详情
NAME            DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
myapp-deploy    2         2         2            2           17d
tomcat-deploy   2         2         2            2           17d

将 kubectl 的 —record 的 flag 设置为 true 可以在 annotation 中记录当前命令创建或者升级了该资源。这在未来会很有用，例如，查看在每个 Deployment revision 中执行了哪些命令。

[root@master yaml]# kubectl get pods --show-labels
NAME                             READY     STATUS    RESTARTS   AGE       LABELS
myapp-deploy-55c6785644-57t85    1/1       Running   0          17d       app=myapp,pod-template-hash=1172341200,release=canary
myapp-deploy-55c6785644-rn7x6    1/1       Running   0          17d       app=myapp,pod-template-hash=1172341200,release=canary
mytomcat                         1/1       Running   2          98d       name=mytomcat
nginx-pod                        1/1       Running   0          3d        app=nginx
tomcat-deploy-58488bcdcd-9xbgz   1/1       Running   0          17d       app=tomcat,pod-template-hash=1404467878,release=canary
tomcat-deploy-58488bcdcd-gnm84   1/1       Running   0          17d       app=tomcat,pod-template-hash=1404467878,release=canary
webapp-f8h5v                     1/1       Running   2          104d      app=webapp
webapp-flpqz                     1/1       Running   2          96d       app=webapp

注意：你必须在 Deployment 中的 selector 指定正确 pod template label（在该示例中是 app = myapp ），不要跟其他的 controller 搞混了（包括 Deployment、ReplicaSet、Replication Controller 等）。Kubernetes 本身不会阻止你这么做，如果你真的这么做了，这些 controller 之间会相互打架，并可能导致不正确的行为。

[root@master yaml]# kubectl describe deployments
Name:                   myapp-deploy
Namespace:              default
CreationTimestamp:      Mon, 02 Aug 2021 07:36:29 +0000
Labels:                 app=myapp
                        release=canary
Annotations:            deployment.kubernetes.io/revision=1
                        kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"name":"myapp-deploy","namespace":"default"},"spec":{"replicas":2,"selector":{...
Selector:               app=myapp,release=canary
Replicas:               2 desired | 2 updated | 2 total | 2 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  25% max unavailable, 25% max surge
Pod Template:
  Labels:  app=myapp
           release=canary
  Containers:
   myapp:
    Image:        ikubernetes/myapp:v2
    Port:         80/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  <none>
NewReplicaSet:   myapp-deploy-55c6785644 (2/2 replicas created)
Events:          <none>


Name:                   tomcat-deploy
Namespace:              default
CreationTimestamp:      Mon, 02 Aug 2021 07:49:00 +0000
Labels:                 app=tomcat
                        release=canary
Annotations:            deployment.kubernetes.io/revision=1
                        kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"name":"tomcat-deploy","namespace":"default"},"spec":{"replicas":2,"selector":...
Selector:               app=tomcat,release=canary
Replicas:               2 desired | 2 updated | 2 total | 2 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  25% max unavailable, 25% max surge
Pod Template:
  Labels:  app=tomcat
           release=canary
  Containers:
   tomcat:
    Image:        tomcat:7-alpine
    Ports:        8080/TCP, 8009/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  <none>
NewReplicaSet:   tomcat-deploy-58488bcdcd (2/2 replicas created)
Events:          <none>
[root@master yaml]# kubectl describe myapp
the server doesn't have a resource type "myapp"
[root@master yaml]# kubectl get rs
NAME                       DESIRED   CURRENT   READY     AGE
myapp-deploy-55c6785644    2         2         2         17d
tomcat-deploy-58488bcdcd   2         2         2         17d
[root@master yaml]# kubectl describe myapp-deploy
the server doesn't have a resource type "myapp-deploy"
[root@master yaml]# kubectl describe deployments
Name:                   myapp-deploy
Namespace:              default
CreationTimestamp:      Mon, 02 Aug 2021 07:36:29 +0000
Labels:                 app=myapp
                        release=canary
Annotations:            deployment.kubernetes.io/revision=1
                        kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"name":"myapp-deploy","namespace":"default"},"spec":{"replicas":2,"selector":{...
Selector:               app=myapp,release=canary
Replicas:               2 desired | 2 updated | 2 total | 2 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  25% max unavailable, 25% max surge
Pod Template:
  Labels:  app=myapp
           release=canary
  Containers:
   myapp:
    Image:        ikubernetes/myapp:v2
    Port:         80/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  <none>
NewReplicaSet:   myapp-deploy-55c6785644 (2/2 replicas created)
Events:          <none>


Name:                   tomcat-deploy
Namespace:              default
CreationTimestamp:      Mon, 02 Aug 2021 07:49:00 +0000
Labels:                 app=tomcat
                        release=canary
Annotations:            deployment.kubernetes.io/revision=1
                        kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"name":"tomcat-deploy","namespace":"default"},"spec":{"replicas":2,"selector":...
Selector:               app=tomcat,release=canary
Replicas:               2 desired | 2 updated | 2 total | 2 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  25% max unavailable, 25% max surge
Pod Template:
  Labels:  app=tomcat
           release=canary
  Containers:
   tomcat:
    Image:        tomcat:7-alpine
    Ports:        8080/TCP, 8009/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  <none>
NewReplicaSet:   tomcat-deploy-58488bcdcd (2/2 replicas created)
Events:          <none>