Function updateRoleLabels

pkg/reconciler/instance/metadata.go:166–218

Make sure that primary and replicas are correctly labelled as such Returns true if the instance needed updating

(
	ctx context.Context,
	cluster *apiv1.Cluster,
	instance *corev1.Pod,
)

//
// Returns true if the instance needed updating
func updateRoleLabels(
	ctx context.Context,
	cluster *apiv1.Cluster,
	instance *corev1.Pod,
) bool {
	contextLogger := log.FromContext(ctx)

	// No current primary, no work to do
	if cluster.Status.CurrentPrimary == "" {
		return false
	}

	if !utils.IsPodActive(*instance) {
		contextLogger.Trace("Ignoring not active Pod during label update",
			"pod", instance.Name, "status", instance.Status)
		return false
	}

	if instance.Labels == nil {
		instance.Labels = make(map[string]string)
	}

	// it is important to note that even if utils.ClusterRoleLabelName is deprecated,
	// we still ensure that the values are aligned between the two fields
	//nolint:staticcheck
	podRole, hasRole := instance.Labels[utils.ClusterRoleLabelName]
	newPodRole, newHasRole := instance.Labels[utils.ClusterInstanceRoleLabelName]

	switch instance.Name {
	case cluster.Status.CurrentPrimary:
		if !hasRole || podRole != specs.ClusterRoleLabelPrimary || !newHasRole ||
			newPodRole != specs.ClusterRoleLabelPrimary {
			contextLogger.Info("Setting primary label", "pod", instance.Name)
			utils.SetInstanceRole(&instance.ObjectMeta, specs.ClusterRoleLabelPrimary)
			return true
		}

	default:
		// This intentionally overwrites the transient ClusterRoleLabelUnhealthy value
		// that the failover path sets on the old primary. This function is only reached
		// once CurrentPrimary == TargetPrimary (the failover guard in the reconcile loop
		// returns early otherwise), so by the time we get here the old primary has been
		// demoted and "replica" is the correct label.
		if !hasRole || podRole != specs.ClusterRoleLabelReplica || !newHasRole ||
			newPodRole != specs.ClusterRoleLabelReplica {
			contextLogger.Info("Setting replica label", "pod", instance.Name)
			utils.SetInstanceRole(&instance.ObjectMeta, specs.ClusterRoleLabelReplica)
			return true
		}
	}

	return false
}

// updateOperatorLabels ensures that the instances are labelled as instances,
// and have the correct instance name