Configure node selector for MetalLB speaker¶

By default, MetalLB speakers are deployed on all Kubernetes 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 the MetalLB speaker node selector:

Using kubeconfig of the management cluster, open the Cluster object of the managed cluster for editing:

kubectl --kubeconfig <pathToManagementClusterKubeconfig> -n <TargetClusterProjectName> edit cluster <TargetClusterName>

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.

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.

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
```
The addition of a node label that is not available in the list of allowed node labels is restricted.