Set kubelet parameters via a configuration file for RKE, RKE2 and K3s clusters

Article Number: 000021322

Environment

An RKE, RKE2 or K3s cluster

Situation

This article details how to configure the Kubernetes kubelet parameters by providing a custom configuration file in an RKE, RKE2, or K3s cluster. Whilst it is still possible to pass kubelet parameters as arguments, even though this is noted as deprecated in the Kubernetes documentation, the following steps enable deployment via a configuration file.

Resolution

RKE2/K3s Clusters

For standalone RKE2 or K3s clusters, refer to the RKE2 or K3s Kubelet configuration documentation.

For Rancher-provisioned RKE2 or K3s clusters, refer to the SUSE Knowledge Base article How to add a kubelet configuration file to nodes in a Rancher-provisioned RKE2 or K3s cluster.

RKE Clusters

Create the desired kubelet configuration file on each node within the cluster (e.g. /etc/kubernetes/kubeconfig.yml).

Add the required extra_args and extra_binds configuration to the kubelet service in the cluster configuration YAML, per the following example:

services:
[...]
  kubelet:
    extra_args:
      config: /etc/kubernetes/kubeletconfig.yml
    extra_binds:
      - "/etc/kubernetes/kubeletconfig.yml:/etc/kubernetes/kubeletconfig.yml"
[...]

For standalone RKE clusters, define these in the cluster.yml file, and invoke rke up to apply the changes.

For Rancher-provisioned RKE clusters, define these within the Cluster Management interface of the Rancher UI, as documented in Editing Clusters with YAML, and click Save to apply the changes.