Expose the VotingApp with an Ingress resource

  1. Traefik Ingress Controller

Since the cluster used in this section is based on k3s, it comes with Traefik Ingress Controller by default. This can be verified using the following command.

$ kubectl get po -n kube-system | grep traefik
helm-install-traefik-crd-vj4hz            0/1     Completed   0          56m
helm-install-traefik-qg2g5                0/1     Completed   1          56m
svclb-traefik-de21cf3d-vctd2              2/2     Running     0          56m
traefik-57b79cf995-vf6qh                  1/1     Running     0          56m
ℹ️
Traefik is one implementation of the Kubernetes Ingress Controller. Other implementations exist including nginx, HAProxy, …

Get the external IP of this load-balancer as you will need it in the next part.

$ kubectl get service -n kube-system | grep traefik
NAME      TYPE           CLUSTER-IP     EXTERNAL-IP    PORT(S)                      AGE
traefik          LoadBalancer   10.43.2.146   192.168.64.8   80:32667/TCP,443:32545/TCP   57m

In this example, the external IP address is 192.168.64.8. This is the IP address of the Ubuntu VM you created using Multipass, in a previous step.

  1. In a file named ingress.yaml, define the specification for an Ingress resource with the following characteristics:
  • Name: vote
  • ingressClassName: traefik
  • All requests to the URL vote.votingapp.com should be redirected to port 80 of the vote-ui service
  • All requests to the URL result.votingapp.com should be redirected to port 80 of the result-ui service

Update your /etc/hosts file so that the URLs vote.votingapp.com and result.votingapp.com resolve to the IP address of the Ingress Controller (the one you get before)

Then you should modify your /etc/hosts file to add the following entry:

...
IP_OF_YOUR_VM vote.votingapp.com result.votingapp.com
If you do not have the necessary permissions to modify your /etc/hosts file, you can use the nip.io service and set the domain names vote.IP_OF_YOUR_VM.nip.io / result.IP_OF_YOUR_VM.nip.io instead of vote.votingapp.com / result.votingapp.com in your Ingress resource definition.

  1. Deploy the application and verify that the vote interface is available at http://vote.votingapp.com and the result interface is available at http://result.votingapp.com (or at http://vote.IP_OF_YOUR_VM.nip.io / http://result.IP_OF_YOUR_VM.nip.io if you are using the nip.io approach).

  2. Delete the application.


Solution
  1. The specification for the Ingress resource is as follows:
ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: vote
spec:
ingressClassName: traefik
rules:
- host: vote.votingapp.com
  http:
    paths:
    - path: /
      pathType: Prefix
      backend:
        service:
          name: vote-ui
          port:
            number: 80
- host: result.votingapp.com
  http:
    paths:
    - path: /
      pathType: Prefix
      backend:
        service:
          name: result-ui
          port:
            number: 80
  1. Deploy the application with the following command from the manifests directory:
kubectl apply -f .

You can then access the different interfaces using real domain names instead of a port number.

Vote

Result

  1. Delete the application with the following command from the manifests directory:
kubectl delete -f .