Container Service for Kubernetes:Expose services with ALB Ingress

On cluster creation

1. Log on to the ACK console and click Create Kubernetes Cluster.

2. In the Component Configuration step, go to the Ingress section and select ALB Ingress.

3. This example uses the New option. Follow the on-screen instructions to create the cluster.

   ALB Instance		Description
   New		Automatically creates an ALB instance, an AlbConfig, and an IngressClass. ALB instance: Automatically creates a standard, pay-as-you-go, public or private ALB instance in the cluster's VPC and configures an HTTP:80 listener. AlbConfig and IngressClass: Automatically creates the corresponding AlbConfig and IngressClass resources in the cluster and associates them with the ALB instance.
   Select Existing VPC This option is available only when the cluster is configured to use an existing Virtual Private Cloud (VPC).		Uses an existing ALB instance and automatically creates an AlbConfig and an IngressClass. The specified ALB instance must be a Standard or WAF-enhanced edition, be in the same VPC as the cluster, and not be associated with another cluster.
   None		Installs only the ALB Ingress Controller component. You must manually create an AlbConfig and an IngressClass later. This is suitable for scenarios where you need to customize the ALB instance configuration.

For an existing cluster

1. Log on to the ACK console. In the left navigation pane, click Clusters.

2. On the Clusters page, click the name of your cluster. In the left navigation pane, click Components and Add-ons.

3. Use the search box or click the Networking tab to find the component. On the ALB Ingress Controller component card, click Install in the lower-right corner.

4. This example uses the New option. Click OK.

   ALB Instance		Description
   New		Automatically creates an ALB instance, an AlbConfig, and an IngressClass. ALB instance: Automatically creates a standard, pay-as-you-go, public or private ALB instance in the cluster's VPC and configures an HTTP:80 listener. AlbConfig and IngressClass: Automatically creates the corresponding AlbConfig and IngressClass resources in the cluster and associates them with the ALB instance.
   Existing		Uses an existing ALB instance and automatically creates an AlbConfig and an IngressClass. The specified ALB instance must be a Standard or WAF-enhanced edition, be in the same VPC as the cluster, and not be associated with another cluster.
   None		Installs only the ALB Ingress Controller component. You must manually create an AlbConfig and an IngressClass later. This is suitable for scenarios where you need to customize the ALB instance configuration.

Console

1. On the Clusters page, click the name of your cluster. In the left navigation pane, click Workloads > Deployments.

2. Click Create from YAML. Select Custom from the Sample Template drop-down list. Then, copy the following content into the template editor and click Create.

   Sample application YAML

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: coffee
     namespace: default
   spec:
     replicas: 2
     selector:
       matchLabels:
         app: coffee
     template:
       metadata:
         labels:
           app: coffee
       spec:
         containers:
         - name: coffee
           image: registry.cn-hangzhou.aliyuncs.com/acs-sample/nginxdemos:latest
           ports:
           - containerPort: 80
   ---
   apiVersion: v1
   kind: Service
   metadata:
     name: coffee-svc
     namespace: default
   spec:
     ports:
     - port: 80
       targetPort: 80
       protocol: TCP
     selector:
       app: coffee
     type: ClusterIP  # When you use the flannel network plugin, the backend Service of an ALB Ingress supports only the NodePort and LoadBalancer types.

3. In the confirmation dialog box, click View and verify that the Pod status is Running.

kubectl

1. Connect to a cluster by using kubectl.

2. Create a file named coffee-deployment-service.yaml that contains the following content.

   Sample application YAML

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: coffee
     namespace: default
   spec:
     replicas: 2
     selector:
       matchLabels:
         app: coffee
     template:
       metadata:
         labels:
           app: coffee
       spec:
         containers:
         - name: coffee
           image: registry.cn-hangzhou.aliyuncs.com/acs-sample/nginxdemos:latest
           ports:
           - containerPort: 80
   ---
   apiVersion: v1
   kind: Service
   metadata:
     name: coffee-svc
     namespace: default
   spec:
     ports:
     - port: 80
       targetPort: 80
       protocol: TCP
     selector:
       app: coffee
     type: ClusterIP  # When you use the flannel network plugin, the backend Service of an ALB Ingress supports only the NodePort and LoadBalancer types.

3. Create the Deployment and Service for the sample application.

   kubectl apply -f coffee-deployment-service.yaml

4. Verify that the Pod status is Running.

    kubectl get pod -l app=coffee

   Expected output:

   NAME                      READY   STATUS    RESTARTS   AGE
   coffee-84bd6*****-*****   1/1     Running   0          4m22s
   coffee-84bd6*****-*****   1/1     Running   0          4m22s

Console

1. In the navigation pane on the left, choose Network > Ingresses. Select the default namespace and click Create Ingress.

2. Specify the following Ingress parameters and click OK.

   • Name: coffee-ingress

   • Domain Name: ingress-demo.com

   • Mappings: Path: /coffee, Match Rule: Prefix, Service: coffee-svc, Port: 80.

     Matching rule (pathType)	Description
     Prefix	Matches the request path based on its prefix. For example, requests for /coffee/1 or /coffee/buy/1 are matched, but requests for /cof or /coffeebuy/1 are not.
     Exact	Matches the request path exactly. Only requests for /coffee are matched.
     ImplementationSpecific	The matching behavior depends on the Ingress controller implementation. For the ALB Ingress Controller, this type is equivalent to an Exact match.

3. Obtain the Endpoint address.

   An ALB Ingress takes about 10 seconds to take effect. You can click the refresh button to get the endpoint information. If the endpoint is not updated after a long time, click the Ingress name and go to the Events tab to troubleshoot issues.

   In the Endpoint column of the Ingress list, find the ALB endpoint address, which is in a format similar to alb-<instance_id>.cn-wulanchabu.alb.aliyuncsslb.com.

4. Test access to the domain and endpoint. An HTTP status code of 200 indicates that the ALB Ingress is working correctly.

   curl -H "Host:ingress-demo.com" http://<endpoint_address>/coffee -s -o /dev/null -w "%{http_code}\n"

kubectl

1. Create a file named coffee-ingress.yaml with the following content. Then, run the kubectl apply -f coffee-ingress.yaml command to create the ALB Ingress.

   apiVersion: networking.k8s.io/v1
   kind: Ingress
   metadata:
     name: coffee-ingress
     namespace: default
   spec:
     ingressClassName: alb
     rules:
     - host: ingress-demo.com
       http:
         paths:
         - path: /coffee
           backend:
             service: 
               name: coffee-svc
               port:
                 number: 80
           pathType: Prefix

   Matching rule (pathType)	Description
   Prefix	Matches the request path based on its prefix. For example, requests for /coffee/1 or /coffee/buy/1 are matched, but requests for /cof or /coffeebuy/1 are not.
   Exact	Matches the request path exactly. Only requests for /coffee are matched.
   ImplementationSpecific	The matching behavior depends on the Ingress controller implementation. For the ALB Ingress Controller, this type is equivalent to an Exact match.

2. View the Ingress and obtain the endpoint address from the ADDRESS field.

   kubectl get ingress coffee-ingress -o jsonpath='{.status.loadBalancer.ingress[0].hostname}'

   Expected output:

   alb-******************.cn-wulanchabu.alb.aliyuncsslb.com

3. Test access to the domain and endpoint. An HTTP status code of 200 indicates that the ALB Ingress is working correctly.

   curl -H "Host:ingress-demo.com" http://<endpoint_address>/coffee -s -o /dev/null -w "%{http_code}\n"