Serving Multiple Ingresses through a single AWS Load Balancer - AWS Load Balancer Operator | Networking

Creating multiple ingresses through a single AWS Load Balancer

You can route the traffic to different services that are part of a single domain through a single AWS Load Balancer (ALB). Each Ingress resource provides different endpoints of the domain.

Creating multiple ingresses through a single AWS Load Balancer

You can route the traffic to multiple Ingresses through a single AWS Load Balancer (ALB) by using the CLI.

Prerequisites

You have an access to the OpenShift CLI (oc).

Procedure

Create an IngressClassParams resource YAML file, for example, sample-single-lb-params.yaml, as follows:

apiVersion: elbv2.k8s.aws/v1beta1 (1)
kind: IngressClassParams
metadata:
  name: single-lb-params (2)
spec:
  group:
    name: single-lb (3)

1	Defines the API group and version of the `IngressClassParams` resource.
2	Specifies the name of the `IngressClassParams` resource.
3	Specifies the name of the `IngressGroup`. All Ingresses of this class belong to this `IngressGroup`.

Create an IngressClassParams resource by running the following command:
```
$ oc create -f sample-single-lb-params.yaml
```

Create an IngressClass resource YAML file, for example, sample-single-lb-class.yaml, as follows:

apiVersion: networking.k8s.io/v1 (1)
kind: IngressClass
metadata:
  name: single-lb (2)
spec:
  controller: ingress.k8s.aws/alb (3)
  parameters:
    apiGroup: elbv2.k8s.aws (4)
    kind: IngressClassParams (5)
    name: single-lb-params (6)

1	Defines the API group and version of the `IngressClass` resource.
2	Specifies the name of the `IngressClass`.
3	Defines the controller name. `ingress.k8s.aws/alb` denotes that all Ingresses of this class should be managed by the `aws-load-balancer-controller`.
4	Defines the API group of the `IngressClassParams` resource.
5	Defines the resource type of the `IngressClassParams` resource.
6	Defines the name of the `IngressClassParams` resource.

Create an IngressClass resource by running the following command:
```
$ oc create -f sample-single-lb-class.yaml
```

Create an AWSLoadBalancerController resource YAML file, for example, sample-single-lb.yaml, as follows:

apiVersion: networking.olm.openshift.io/v1
kind: AWSLoadBalancerController
metadata:
  name: cluster
spec:
  subnetTagging: Auto
  ingressClass: single-lb (1)

1	Defines the name of the `IngressClass` resource.

Create an AWSLoadBalancerController resource by running the following command:
```
$ oc create -f sample-single-lb.yaml
```

Create an Ingress resource YAML file, for example, sample-multiple-ingress.yaml, as follows:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-1 (1)
  annotations:
    alb.ingress.kubernetes.io/scheme: internet-facing (2)
    alb.ingress.kubernetes.io/group.order: "1" (3)
    alb.ingress.kubernetes.io/target-type: instance (4)
spec:
  ingressClassName: single-lb (5)
  rules:
  - host: example.com (6)
    http:
        paths:
        - path: /blog (7)
          pathType: Prefix
          backend:
            service:
              name: example-1 (8)
              port:
                number: 80 (9)
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-2
  annotations:
    alb.ingress.kubernetes.io/scheme: internet-facing
    alb.ingress.kubernetes.io/group.order: "2"
    alb.ingress.kubernetes.io/target-type: instance
spec:
  ingressClassName: single-lb
  rules:
  - host: example.com
    http:
        paths:
        - path: /store
          pathType: Prefix
          backend:
            service:
              name: example-2
              port:
                number: 80
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-3
  annotations:
    alb.ingress.kubernetes.io/scheme: internet-facing
    alb.ingress.kubernetes.io/group.order: "3"
    alb.ingress.kubernetes.io/target-type: instance
spec:
  ingressClassName: single-lb
  rules:
  - host: example.com
    http:
        paths:
        - path: /
          pathType: Prefix
          backend:
            service:
              name: example-3
              port:
                number: 80

1	Specifies the name of an ingress.
2	Indicates the load balancer to provision in the public subnet and makes it accessible over the internet.
3	Specifies the order in which the rules from the Ingresses are matched when the request is received at the load balancer.
4	Indicates the load balancer will target OpenShift nodes to reach the service.
5	Specifies the Ingress Class that belongs to this ingress.
6	Defines the name of a domain used for request routing.
7	Defines the path that must route to the service.
8	Defines the name of the service that serves the endpoint configured in the ingress.
9	Defines the port on the service that serves the endpoint.

Create the Ingress resources by running the following command:
```
$ oc create -f sample-multiple-ingress.yaml
```