Machine Bootstrap Configuration

When creating a cluster managed by Cluster API, you have to define how new machines joining the cluster should be bootstrapped.

This is achieved by defining one or more BootstrapConfigTemplate resources.

For example, if you are using the kubeadm bootstrap provider.

---
apiVersion: bootstrap.cluster.x-k8s.io/v1beta2
kind: KubeadmConfigTemplate
metadata:
  name: my-cluster-workers
spec:
  template:
    spec:
      joinConfiguration:
        nodeRegistration:
          criSocket: /var/run/containerd/containerd.sock
          kubeletExtraArgs:
          - name: cloud-provider
            value: external
      users:
      - name: my-cluster-admin
        sshAuthorizedKeys:
        - '...'
        sudo: ALL=(ALL) NOPASSWD:ALL

See documentation for the specific bootstrap provider for more details.

Important

Depending on the bootstrap provider you are planning to use, some additional prerequisites should be satisfied before configuring a cluster with Cluster API. See Required configuration for common providers for more details.

Tip

If you are using ClusterClass, the ClusterClass author will take ownership of the responsibility of defining BootstrapConfigTemplate resources, hiding all the complexity.

ClusterClass users can configure machine bootstrap options directly from the Cluster object. See Cluster Creation.