kuma - exposing your application to the external world

To expose your application to the world, let use the demo app given by Kong/Kuma. This means we don't need to do port forward to post a payload to our app here. We can do it via localhost. 

Run the following command. I assume you have installed  your kuma control plane.

To install the demo app.

kubectl apply -f https://raw.githubusercontent.com/kumahq/kuma-counter-demo/refs/heads/main/k8s/000-with-kuma.yaml

Once you have installed it, then please the following so we can see the layout:

kubectl port-forward svc/demo-app -n kuma-demo 5050:5050

The demo app should just look like this 

Let's expose it to the external world now via port 80 and not 8080 as specified in the documentation. we can do that by creating MeshGatewayInstance, MeshGateway and MeshHttpRoute. We are also creating the MeshTrafficPermission here.

Run the following yaml.

---

apiVersion: kuma.io/v1alpha1

kind: MeshGatewayInstance

metadata:

  name: edge-gateway

  namespace: kuma-demo

spec:

  replicas: 1

  serviceType: LoadBalancer

---

apiVersion: kuma.io/v1alpha1

kind: MeshGateway

mesh: default

metadata:

  name: edge-gateway

  namespace: kuma-demo

spec:

  conf:

    listeners:

      - port: 80

        protocol: HTTP

  selectors:

    - match:

        kuma.io/service: edge-gateway_kuma-demo_svc

---

apiVersion: kuma.io/v1alpha1

kind: MeshHTTPRoute

metadata:

  name: demo-app-edge-gateway

  namespace: kuma-system

spec:

  targetRef:

    kind: MeshGateway

    name: edge-gateway

  to:

    - targetRef:

        kind: Mesh

      rules:

        - default:

            backendRefs:

              - kind: MeshService

                name: demo-app

                namespace: kuma-demo

                port: 5050

          matches:

            - path:

                type: PathPrefix

                value: /

---

apiVersion: kuma.io/v1alpha1

kind: MeshTrafficPermission

metadata:

  namespace: kuma-demo

  name: demo-app

spec:

  targetRef:

    kind: Dataplane

    labels:

      app: demo-app

  from:

    - targetRef:

        kind: MeshSubset

        tags:

          kuma.io/service: edge-gateway_kuma-demo_svc

      default:

        action: Allow

You will see that we have an additional pod call edge-gateway.

Then try to discover the service load balancer IP address. Since i am using Docker desktop, it will be localhost. 

Once I have those resource created, I can just run 

Invoke-WebRequest -Uri http://localhost:80/api/counter -Method POST -verbose

Then you can see my counter starts to increment.