You do not need to create or manage nodes in serverless Kubernetes (ASK) clusters. This frees you from maintaining cloud resources of your applications and allows you to focus on your business development instead of managing the underlying infrastructure. This topic describes how to deploy web applications in ASK clusters.

Background information

ASK cluster support standard Kubernetes semantics and API operations. You can create cluster resources with a few clicks, such as Deployments, StatefulSets, Jobs, services, Ingresses, and custom resources. You can also use Helm to deploy a variety of Kubernetes-native applications in ASK clusters.

Procedure

  1. Use kubectl to connect to a cluster.
  2. Create an nginx.yaml file and copy the following content into the file.
    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. Run the following command to deploy an NGINX application in the ASK cluster.
    kubectl apply -f nginx.yaml
# Output:
service/nginx-service created
deployment.apps/nginx-deploy created
  4. Run the following command to view the status of pods and services deployed in the cluster. You can use the IP address of the created SLB instance to access the NGINX application.
    kubectl get pod
# Output:
NAME                            READY   STATUS    RESTARTS   AGE
nginx-deploy-55d8dcf755-bxk8n   1/1     Running   0          36s
nginx-deploy-55d8dcf755-rchhq   1/1     Running   0          36s

kubectl get svc
# Output:
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

curl 47.57. **. **
# Output:
<! DOCTYPE html>
<html>
<head>
<title>Welcome to nginx! </title>
...
</html>
  5. Run the following command to scale out the NGINX Deployment.
    kubectl get deploy
# Output:
NAME           READY   UP-TO-DATE   AVAILABLE   AGE
nginx-deploy   2/2     2            2           9m32s

kubectl scale deploy nginx-deploy --replicas=10
# Output:
deployment.extensions/nginx-deploy scaled

kubectl get pod
# Output:
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. Run the following command to configure scaling settings for Horizontal Pod Autoscaler (HPA). HPA automatically scales out the Deployment when the CPU usage exceeds the specified threshold.
    kubectl scale deploy nginx-deploy --replicas=1
# Output:
deployment.extensions/nginx-deploy scaled

kubectl get pod
# Output:
NAME                            READY   STATUS    RESTARTS   AGE
nginx-deploy-55d8dcf755-rchhq   1/1     Running   0          16m

kubectl autoscale deployment nginx-deploy --cpu-percent=50 --min=1 --max=10
# Output:
horizontalpodautoscaler.autoscaling/nginx-deploy autoscaled

kubectl get hpa
# Output:
NAME           REFERENCE                 TARGETS   MINPODS   MAXPODS   REPLICAS   AGE
nginx-deploy   Deployment/nginx-deploy   0%/30%    1         10        1          35s