ASK集群无需管理节点，无需进行节点的安全维护等运维操作，满足您对应用托管的免运维诉求，让您关注在应用而非底层基础设施管理。本文介绍如何通过ASK部署在线web应用，实现应用免运维托管。

背景信息

ASK支持标准Kubernetes的语义和API，您可以一键创建Deployment/StatefulSet/Jobs/Service/Ingress/CRD等资源，也可以使用Helm部署各种Kubernetes生态应用。

操作步骤

  1. 通过kubectl连接Kubernetes集群。
  2. 按照以下内容创建名为nginx的YAML文件。
    apiVersion: v1
kind: Service
metadata:
  name: nginx-service
spec:
  ports:
  - port: 80
    protocol: TCP
  selector:
    app: nginx
  type: LoadBalancer
---
apiVersion: apps/v1beta2
kind: Deployment
metadata:
  name: nginx-deploy
  labels:
    app: nginx
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image:  nginx:alpine
        ports:
        - containerPort: 80
        resources:
          requests:
            cpu: "2"
            memory: "4Gi"
  3. 部署Nginx示例应用。
    kubectl apply -f nginx.yaml
    service/nginx-service created
deployment.apps/nginx-deploy created
  4. 查看Pod和Serivce状态，并通过SLB IP访问Nginx应用。
    1. 查看Pod状态。
      kubectl get pod
      nginx-deploy-55d8dcf755-bxk8n   1/1     Running   0          36s
nginx-deploy-55d8dcf755-rchhq   1/1     Running   0          36s
    2. 查看Serivce状态。
      kubectl get svc
      NAME            TYPE           CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
kubernetes      ClusterIP      172.**.*.*     <none>        443/TCP        10d
nginx-service   LoadBalancer   172.19.*.***   47.57.**.**   80:32278/TCP   39s
    3. 通过SLB IP访问Nginx应用。
      curl 47.57.**.**
      <!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
...
</html>
  5. 扩容Deployment。
    1. 查看Deployment。
      kubectl get deploy
      NAME           READY   UP-TO-DATE   AVAILABLE   AGE
nginx-deploy   2/2     2            2           9m32s
    2. 扩容Deployment。
      kubectl scale deploy nginx-deploy --replicas=10
      deployment.extensions/nginx-deploy scaled
    3. 查看扩容后的Pod。
      kubectl get pod
      NAME                            READY   STATUS    RESTARTS   AGE
nginx-deploy-55d8dcf755-8jlz2   1/1     Running   0          39s
nginx-deploy-55d8dcf755-9jbzk   1/1     Running   0          39s
nginx-deploy-55d8dcf755-bqhcz   1/1     Running   0          38s
nginx-deploy-55d8dcf755-bxk8n   1/1     Running   0          10m
nginx-deploy-55d8dcf755-cn6x9   1/1     Running   0          38s
nginx-deploy-55d8dcf755-jsqjn   1/1     Running   0          38s
nginx-deploy-55d8dcf755-lhp8l   1/1     Running   0          38s
nginx-deploy-55d8dcf755-r2clb   1/1     Running   0          38s
nginx-deploy-55d8dcf755-rchhq   1/1     Running   0          10m
nginx-deploy-55d8dcf755-xspnt   1/1     Running   0          38s
  6. 配置HPA，可以让应用随着负载压力自动进行弹性扩容。当应用的CPU负载增高时，将水平扩容出更多的Pod副本。
    1. 将应用副本缩容到1个。
      kubectl scale deploy nginx-deploy --replicas=1
      deployment.extensions/nginx-deploy scaled
    2. 查看Pod。
      kubectl get pod
      NAME                            READY   STATUS    RESTARTS   AGE
nginx-deploy-55d8dcf755-rchhq   1/1     Running   0          16m
    3. 配置HPA。
      kubectl autoscale deployment nginx-deploy --cpu-percent=50 --min=1 --max=10
      horizontalpodautoscaler.autoscaling/nginx-deploy autoscaled
    4. 查看HPA。
      kubectl get hpa
      NAME           REFERENCE                 TARGETS   MINPODS   MAXPODS   REPLICAS   AGE
nginx-deploy   Deployment/nginx-deploy   0%/30%    1         10        1          35s