message ConfigMapEnvSource {
  // The ConfigMap to select from.
  optional LocalObjectReference localObjectReference = 1;

  // Specify whether the ConfigMap must be defined
  // +optional
  optional bool optional = 2;
}

// Selects a key from a ConfigMap.
// +structType=atomic
message ConfigMapKeySelector {
  // The ConfigMap to select from.
  optional LocalObjectReference localObjectReference = 1;

   ([#109525](https://github.com/kubernetes/kubernetes/pull/109525), [@jonyhy96](https://github.com/jonyhy96))

### Feature

- 'Added selector validation to `HorizontalPodAutoscaler`: when multiple HPAs
  select the same set of Pods, scaling now will be disabled for those HPAs with
  the reason `AmbiguousSelector`. This change also covers a case when multiple HPAs
  point to the same deployment.'