Expose Node labels via downward API

[docandrew]

Enhancement Description

• One-line enhancement description (can be used as a release note): Expose node labels via downward API
• Kubernetes Enhancement Proposal:
• Discussion Link:
• Primary contact (assignee):
• Responsible SIGs: sig-node
• Enhancement target (which target equals to which milestone):
  • Alpha release target (x.y):
  • Beta release target (x.y):
  • Stable release target (x.y):
• Alpha
  • KEP (k/enhancements) update PR(s):
  • Code (k/k) update PR(s):
  • Docs (k/website) update PR(s):

Please keep this description up to date. This will help the Enhancement Team to track the evolution of the enhancement efficiently.

[docandrew]

/sig node