`no matches for kind "HorizontalPodAutoscaler" in version "autoscaling/v2beta2"` error during a Helm upgrade after upgrading Kubernetes to 1.26

We have recently upgraded our Kubernetes cluster to 1.26.

We are now receiving the following error when attempting helm upgrades on the Kong deployment and the upgrade fails:

Error: unable to build kubernetes objects from current release manifest: resource mapping not found for name: "kong" namespace: "kong" from "": no matches for kind "HorizontalPodAutoscaler" in version "autoscaling/v2beta2"

This issue occurs because autoscaling/v2beta2 has been removed as of Kubernetes version 1.26. Possibly due to using an outdated Helm chart to install Kong, your helm release secret/configmap (where the current configuration from your helm deployment is stored) still has an entry for autoscaling/v2beta2.

In order to remedy this we need to take the following steps:

• Get the name of the Secret or Configmap associated with the latest deployed release:
  • Secrets backend: kubectl get secret -l owner=helm,status=deployed,name=<release_name> --namespace <release_namespace> | awk '{print $1}' | grep -v NAME
  • ConfigMap backend: kubectl get configmap -l owner=helm,status=deployed,name=<release_name> --namespace <release_namespace> | awk '{print $1}' | grep -v NAME
• Get latest deployed release details:
  • Secrets backend: kubectl get secret <release_secret_name> -n <release_namespace> -o yaml > release.yaml
  • ConfigMap backend: kubectl get configmap <release_configmap_name> -n <release_namespace> -o yaml > release.yaml
• Backup the release in case you need to restore if something goes wrong:
  • cp release.yaml release.bak
  • In case of emergency, restore: kubectl apply -f release.bak -n <release_namespace>
• Decode the release object:
  • Secrets backend: cat release.yaml | grep -oP '(?<=release: ).*' | base64 -d | base64 -d | gzip -d > release.data.decoded
  • ConfigMap backend: cat release.yaml | grep -oP '(?<=release: ).*' | base64 -d | gzip -d > release.data.decoded
• Open the decoded object in a text editor (we recommend Visual Studio Code), CTRL-F for v2beta2 and change this to v2
• Encode the edited release object:
  • Secrets backend: cat release.data.decoded | gzip | base64 | base64
  • ConfigMap backend: cat release.data.decoded | gzip | base64
• Create a patch.json file locally with the following fields:

{
  "data": {
    "release": "YOUR_NEW_ENCODED_RELEASE_DATA"
  }
}

Ensure that there are no whitespaces or line breaks in the encoded release object (many text editors/linux shells will add line breaks)

• Apply the patch to your secret with the following command:

kubectl patch secret <secret_name> -n <secret_namespace> --patch-file=patch.json

You should now be able to helm upgrade normally.