Tech Tip – Configuring RKE2 Nginx Ingress using a HelmChartConfig Resource

The RKE2 documentation is there, but, well, it is not quite as detailed as I have seen in other areas. This is a quick tip for customizing your Nginx Ingress controllers when using RKE2

Using Nginx Ingress in RKE2

By default, an RKE2 cluster deploys the nginx-ingress Helm chart. That’s great, except that you may need to customize that chart. This is where the HelmChartConfig resource is used.

RKE2 uses HelmChartConfig custom resource definitions (CRDs) to allow you to set configuration options for their default Helm deployments. This is pretty useful, and seemed straightforward, except I had a hard time figuring out HOW to set the options.

Always easier than I expect

The RKE2 documentation points you to the nginx-ingress chart, but it took me a bit to realize that the connection was as simple as setting the valuesContent value in the HelmChartConfig spec to whatever values I wanted to pass in to Nginx.

apiVersion: helm.cattle.io/v1
kind: HelmChartConfig
metadata:
  name: rke2-ingress-nginx
  namespace: kube-system
spec:
  valuesContent: |-
    controller:
      config:
        use-forwarded-headers: "true"
        proxy-buffer-size: "256k"
        proxy-buffer-number: "4"
        large-client-header-buffers: "4 16k"
      metrics:
        enabled: true
        serviceMonitor:
          enabled: true
          additionalLabels:
            cluster: nonproduction

The above sets some configuration values in the controller AND enables metrics collection using the ServiceMonitor object. For Nginx, valid values for valuesContent are the same as values in the chart’s values.yaml file.

Works with other charts

RKE2 provides additional charts that can be deployed and customized with similar methods. There are charts which are deployed by default, and they provide instructions on disabling them. However, the same HelmChartConfig method above can be used to customize the chart installs as well.