Configuring ALB Ingress Controller

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Available in VPC

You can route traffic by integrating Kubernetes Ingress with Load Balancer through ALB Ingress Controller.

When Ingress is created in the Kubernetes system, ALB Ingress Controller uses the values set at Ingress to create a Load Balancer instance. When an instance is created, the Ingress Rule uses the set service's node port as the port value to create a target group and register it to the instance.

Install ALB Ingress Controller

To prepare the ALB Ingress Controller after installing in the cluster:

1. Install the ALB Ingress Controller by running the command corresponding to each Region:

   Note

   If the cluster’s hypervisor is KVM, you can use ALB Ingress Controller without installation as it is included by default.

   • alb-ingress-controller is created in the kube-system namespace, and necessary ServiceAccount, ClusterRole, ClusterRoleBinding, and IngressClass are created together.

   • Korea

     kubectl --kubeconfig=$KUBE_CONFIG apply -f https://raw.githubusercontent.com/NaverCloudPlatform/nks-alb-ingress-controller/main/docs/install/pub/install.yaml
     

     • In Kubernetes versions below 1.19, install https://raw.githubusercontent.com/NaverCloudPlatform/nks-alb-ingress-controller/v0.3.1/docs/install/pub/install.yaml.

   • Singapore

     kubectl --kubeconfig=$KUBE_CONFIG apply -f https://raw.githubusercontent.com/NaverCloudPlatform/nks-alb-ingress-controller/main/docs/install/pub-sg/install.yaml
     

     • In Kubernetes versions below 1.19, install https://raw.githubusercontent.com/NaverCloudPlatform/nks-alb-ingress-controller/v0.3.1/docs/install/pub-sg/install.yaml.

   • Japan

     kubectl --kubeconfig=$KUBE_CONFIG apply -f https://raw.githubusercontent.com/NaverCloudPlatform/nks-alb-ingress-controller/main/docs/install/pub-jp/install.yaml
     

     • In Kubernetes versions below 1.19, install https://raw.githubusercontent.com/NaverCloudPlatform/nks-alb-ingress-controller/v0.3.1/docs/install/pub-jp/install.yaml.

2. Check if the ALB Ingress Controller is running normally.

kubectl --kubeconfig=$KUBE_CONFIG get pods -n kube-system -l app.kubernetes.io/name=alb-ingress-controller

3. Add the spec.ingressClassName: alb field to the resources of Ingress.
   • In Kubernetes versions below 1.19, add kubernetes.io/ingress.class: alb annotation.

ALB Ingress Controller setting and annotation

Default ALB Ingress Controller setting

The default setting of the ALB Ingress Controller is as follows:

• Service type: NodePort
  All services to be exposed through Ingress must be created in the NodePort type.
• Default Rule
  Default Rule is applied when there is no matching rule, and it can be set in spec.defaultBackend.
  You cannot configure rules and use-annotations separately, and a default target group set to Port 80 is created if not configured.
• Rule Priority
  Priority is determined according to the order of rules defined in Ingress. The priority of the topmost rule is set to 1.

ALB Ingress Controller annotation

You can use annotations in Kubernetes Ingress and service objects to change settings.

Use the required annotations while referring to the following table: All annotations of the ALB Ingress Controller start with alb.ingress.kubernetes.io/.

• alb.ingress.kubernetes.io/actions.${actionName}: Additional functions of the Listener Rule can be set by writing a string in the JSON format according to the actions model. Set the service.name of the rule set to the Ingress you want to use as ${actionName} and set service.port.name as use-annotation to have the annotation applied.

• alb.ingress.kubernetes.io/conditions.${conditionName}: In addition to the Host and Path conditions defined in Ingress, other conditions can be additionally set by writing a string in the JSON format according to the conditions model. These conditions are applied to the service with the serviceName that matches ${conditionName} in Ingress Rule.

Example codes

For detailed example of ALB Ingress Controller, see ALB Ingress Controller use cases.