kube-component-options.md

Configuring Kubernetes Components

Under certain scenarios, users might want to set flags that are not set by default, or they might want to override the value of certain flags that are passed to the Kubernetes components.

Each Kubernetes component has a corresponding section in the plan file, through which specific configuration flags can be set or overridden. There is a subset of protected flags that cannot be overridden, as they depend on configuration that is managed by KET.

When using this feature, you must keep in mind that an invalid configuration could prevent the cluster from functioning properly.

Configuring the API Server

The Kubernetes API Server options can be set or overridden in the plan file using the cluster.kube_apiserver.option_overrides field.

For example:

cluster:
...
  kube_apiserver:
    option_overrides:
      "audit-log-path": "/var/log/kube-apiserver.log"
      "event-ttl": "2h0m0s"
      "runtime-config": "batch/v2alpha1=true"

Configuring the Controller Manager

The Kubernetes Controller Manager options can be set or overridden in the plan file using the cluster.kube_controller_manager.option_overrides field.

Configuring the Scheduler

The Kubernetes Scheduler options can be set or overridden in the plan file using the cluster.kube_scheduler.option_overrides field.

Configuring the Kubelet

The Kubelet options can be set or overridden in the plan file using the cluster.kubelet.option_overrides field. This configuration is applied to all Kubelets in the cluster.

The Kubelet options can also be set at the node level using the kubelet.option_overrides field of each node.

For example:

cluster:
  kubelet:
    option_overrides:
      max-pods: 50
...
...
worker:
  expected_count: 1
  nodes:
    host: my-worker
    ip: 10.0.20.1
    kubelet:
      option_overrides:
        max-pods: 120

Configuring the Kube Proxy

The Kube Proxy options can be set or overridden in the plan file using the cluster.kube_proxy.option_overrides field.