Expose Storage Metrics

[jingxu97]

Feature Description

• One-line feature description (can be used as a release note): Expose storage metrics to end users
• Primary contact (assignee): @vkamra @jingxu97
• Responsible SIGs: @kubernetes/sig-storage-feature-requests
• Design proposal link (community repo): Proposal for Exposing Storage Metrics community#855
• Reviewer(s) - (for LGTM) recommend having 2+ reviewers (at least one from code-area OWNERS file) agreed to review. Reviewers from multiple companies preferred: @derekwaynecarr, @vishh, @dashpole
• Approver (likely from SIG/area to which feature belongs): @thockin, @vishh, @derekwaynecarr
• Feature target (which target equals to which milestone):
  • Stable release target (x.y): 1.8/1.9

[tamalsaha]

cc: @aerokite

[idvoretskyi]

@jingxu97 please, update the features tracking board with the relevant data.