Configure node selectors for MetalLB speakers

By default, MetalLB speakers are deployed on all Kubernetes nodes except master nodes. You can configure MetalLB to run its speakers on a particular set of nodes. This decreases the number of nodes that should be connected to external network. In this scenario, only a few nodes are exposed for ingress traffic from the outside world.

To customize a node selector for a MetalLB speaker:

  1. Using kubeconfig of the MOSK management cluster, open the MOSK Cluster object for editing:

    kubectl --kubeconfig <pathToManagementClusterKubeconfig> -n <MOSKClusterNamespace> edit cluster <MOSKClusterName>

  2. In the spec:providerSpec:value:helmReleases section, add the speaker.nodeSelector field for metallb:

    spec:
  ...
  providerSpec:
    value:
      ...
      helmReleases:
      - name: metallb
        values:
          ...
          speaker:
            nodeSelector:
              metallbSpeakerEnabled: "true"

    The metallbSpeakerEnabled: "true" parameter in this example is the label on Kubernetes nodes where MetalLB speakers will be deployed. It can be an already existing node label or a new one.

    You can add user-defined labels to nodes using the nodeLabels field.

    This field contains the list of node labels to be attached to a node for the user to run certain components on separate cluster nodes. The list of allowed node labels is located in the Cluster object status providerStatus.releaseRef.current.allowedNodeLabels field.

    If the value field is not defined in allowedNodeLabels, a label can have any value. For example:

    allowedNodeLabels:
- displayName: Stacklight
  key: stacklight

    Before or after a machine deployment, add the required label from the allowed node labels list with the corresponding value to spec.providerSpec.value.nodeLabels in machine.yaml. For example:

    nodeLabels:
- key: stacklight
  value: enabled

    Adding of a node label that is not available in the list of allowed node labels is restricted.