Building a Continuous Deployment Pipeline Using LKE (Part 9): Installing Traefik

Slide deck: Cloud Native Continuous Deployment with GitLab, Helm, and Linode Kubernetes Engine: Installing Traefik (Slide #143)

Traefik is a popular Ingress Controller for Kubernetes, which manages external access to the cluster and provides load balancing functionality. This section discusses installing Traefik, configuring an Ingress within our YAML file, and testing things out.

• Main guide: Building a Continuous Deployment Pipeline Using LKE
• Previous section: Part 8: ExternalDNS
• Next section: Part 10: Installing metrics-server

Here’s a copy of the text contained within this section of the presentation. A link to the source file can be found within each slide of the presentation. Some formatting may have been changed.

• Traefik is going to be our Ingress Controller

• Let’s install it with a Helm chart, in its own namespace

• First, let’s add the Traefik chart repository:

  helm repo add traefik https://helm.traefik.io/traefik
  

• Then, install the chart:

  helm upgrade --install traefik traefik/traefik \ --create-namespace --namespace traefik \ --set "ports.websecure.tls.enabled=true"
  

(that option that we added enables HTTPS, it will be useful later!)

• Let’s create an Ingress resource!

• If we’re using Kubernetes 1.20 or later, we can simply do this:

  kubectl create ingress web \--rule=ingress-is-fun.cloudnative.party/*=web:80
  

  (make sure to update and use your own domain)

• Check that the Ingress was correctly created:

  kubectl get ingress
  kubectl describe ingress
  

If we’re using Kubernetes 1.19 or earlier, we’ll need some YAML

• This is how we do it with YAML:

  kubectl apply -f- <<EOF
  apiVersion: networking.k8s.io/v1
  kind: Ingress
  metadata:
    name: web
  spec:
    rules:
    - host: ingress-is-fun.cloudnative.party
      http:
        paths:
        - path: /
          backend:
            serviceName: web
            servicePort: 80
  EOF
  

• Note how we used the latest v1 Ingress version on the previous YAML, as the vibeta1 api version has been deprecated.

• Try to connect to the Ingress host name (in my example, http://ingress-is-fun.cloudnative.party/)
• Normally, it doesn’t work (yet) 🤔
• Let’s look at kubectl get ingress again
• ExternalDNS is trying to create records mapping HOSTS to ADDRESS
• But the ADDRESS field is currently empty!
• We need to tell Traefik to fill that ADDRESS field

• There is a “magic” flag to tell Traefik to update the address status field

• Let’s update our Traefik install:

  helm upgrade --install traefik traefik/traefik \
      --create-namespace --namespace traefik \
      --set "ports.websecure.tls.enabled=true" \
      --set "providers.kubernetesIngress.publishedService.enabled=true"
  

• Check the output of kubectl get ingress (there should be an address now)
• Check the logs of ExternalDNS (there should be a mention of the new DNS record)
• Try again to connect to the HTTP address (now it should work)
• Note that some of these operations might take a minute or two (be patient!)