本文介绍通过Kubernetes Deployment对象如何去运行一个应用.
You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using Minikube, or you can use one of these Kubernetes playgrounds:
To check the version, enter kubectl version
.
你可以通过创建一个Kubernetes Deployment对象来运行一个应用, 可以在一个YAML文件中描述Deployment. 例如, 下面这个YAML文件描述了一个运行nginx:1.7.9 Docker镜像的Deployment:
deployment.yaml docs/tasks/run-application
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通过YAML文件创建一个Deployment:
kubectl create -f https://k8s.io/docs/tasks/run-application/deployment.yaml
展示Deployment相关信息:
kubectl describe deployment nginx-deployment
user@computer:~/website$ kubectl describe deployment nginx-deployment
Name: nginx-deployment
Namespace: default
CreationTimestamp: Tue, 30 Aug 2016 18:11:37 -0700
Labels: app=nginx
Annotations: deployment.kubernetes.io/revision=1
Selector: app=nginx
Replicas: 2 desired | 2 updated | 2 total | 2 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 1 max unavailable, 1 max surge
Pod Template:
Labels: app=nginx
Containers:
nginx:
Image: nginx:1.7.9
Port: 80/TCP
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
Progressing True NewReplicaSetAvailable
OldReplicaSets: <none>
NewReplicaSet: nginx-deployment-1771418926 (2/2 replicas created)
No events.
列出deployment创建的pods:
kubectl get pods -l app=nginx
NAME READY STATUS RESTARTS AGE
nginx-deployment-1771418926-7o5ns 1/1 Running 0 16h
nginx-deployment-1771418926-r18az 1/1 Running 0 16h
展示某一个pod信息:
kubectl describe pod
该处 <pod-name>
指某一pod的名称.
你可以通过更新一个新的YAML文件来更新deployment. 下面的YAML文件指定该deployment镜像更新为nginx 1.8.
deployment-update.yaml docs/tasks/run-application
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应用新的YAML:
kubectl apply -f https://k8s.io/docs/tutorials/stateless-application/deployment-update.yaml
查看该deployment创建的pods以新的名称同时删除旧的pods:
kubectl get pods -l app=nginx
你可以通过应用新的YAML文件来增加Deployment中pods的数量. 该YAML文件将replicas
设置为4, 指定该Deployment应有4个pods:
deployment-scale.yaml docs/tasks/run-application
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应用新的YAML文件:
kubectl apply -f https://k8s.io/docs/tutorials/stateless-application/deployment-scale.yaml
验证Deployment有4个pods:
kubectl get pods -l app=nginx
输出的结果类似于:
NAME READY STATUS RESTARTS AGE
nginx-deployment-148880595-4zdqq 1/1 Running 0 25s
nginx-deployment-148880595-6zgi1 1/1 Running 0 25s
nginx-deployment-148880595-fxcez 1/1 Running 0 2m
nginx-deployment-148880595-rwovn 1/1 Running 0 2m
通过名称删除deployment:
kubectl delete deployment nginx-deployment
创建一个多副本应用首选方法是使用Deployment,反过来使用ReplicaSet. 在Deployment和ReplicaSet加入到Kubernetes之前, 多副本应用通过ReplicationController来配置.
此页是否对您有帮助?
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