WIP Add ProviderID

The cluster autoscaler expects this to be set on both machines
and nodes, and typically the cluster-api provider will set the
value in the spec for the machine e.g

https://github.com/openshift/cluster-api-provider-aws/blob/master/pkg/actuators/machine/reconciler.go#L280

In the baremetal case though there's no "provider" to set the value
on the node, so we also update that correspondingly (TODO)

https://bugzilla.redhat.com/show_bug.cgi?id=1852959

pkg/cloud/baremetal/actuators/machine/actuator.go

@@ -260,6 +260,11 @@ func (a *Actuator) Update(ctx context.Context, machine *machinev1beta1.Machine)
 		return err
 	}
 
+	err = a.ensureProviderID(ctx, machine, host)
+	if err != nil {
+		return err
+	}
+
 	if err := a.handleNodeFinalizer(ctx, machine); err != nil {
 		return err
 	}
@@ -498,6 +503,19 @@ func (a *Actuator) ensureAnnotation(ctx context.Context, machine *machinev1beta1
 	return true, a.client.Update(ctx, machine)
 }
 
+func (a *Actuator) ensureProviderID(ctx context.Context, machine *machinev1beta1.Machine, host *bmh.BareMetalHost) (error) {
+	if host.Status.Provisioning.ID != "" {
+		providerID := "baremetal:" + host.Status.Provisioning.ID
+		existingProviderID := machine.Spec.ProviderID
+		if existingProviderID == nil || *existingProviderID != providerID {
+			log.Printf("Setting ProviderID %s for machine %s.", providerID, machine.Name)
+			machine.Spec.ProviderID = &providerID
+			return a.client.Update(ctx, machine)
+		}
+	}
+	return nil
+}
+
 // handleNodeFinalizer adds finalizer to Node if not already exists
 // it also store the node annotations and labels on Machine annotations
 // upon node deletion