Traefik upgrade and tests

Upgrading older versions of k3s to a new one and having the old Traefik v1 seems to be a common issue that k3s users are facing. There are a several of issues which happen when upgrading without changing API resources (ingress):

• Failed to list *v1beta1.Ingress: the server could not find the requested resource (get ingresses.extensions)

• Issue #4967 · k3s-io/k3s · GitHub

The common solution which people recommend is simply upgrade Traefik. There are plenty of guides even official ones from Traefik. We recommend the following workflow with Helm:

Upgrade Traefik with Helm

Setup: From Kubernetes v1.20.x to v1.24.X with Traefik helm chart 1.8.1

1. Uninstall current Traefik version v1.8x.x helm uninstall traefik -n kube-system

2. Make sure Helm has everything it needs to install Traefik v2 helm repo add traefik https://helm.traefik.io/traefik helm repo update

3. Install new Traefik v2 (GitHub - traefik/traefik-helm-chart: Traefik v2 helm chart) helm install traefik traefik/traefik

4. Migrate your configurations and ingress definitions to the new Traefik v2 by using the official guides and tools:

   • Traefik V2 Migration Documentation - Traefik

   • GitHub - traefik/traefik-migration-tool: A migration tool from Traefik v1 to Traefik v2.