The API server's "insecure-port" has been deprecated since 1.10, but never had a deadline for removal. Previous efforts to remove the port have been blocked by requirements for http healthz checks (#43784).

I propose publishing a deadline to remove the feature in v1.20. This means that in v1.19 we:

1. Update the deprecation notice to indicate that removal will happen in v1.20 (rather than a "future release")
2. Add an [action required] release note to highlight the removal
3. Figure out a path forward to meeting healthz or other requriments

For item 3, there are already out-of-tree solutions available today, such as a healthz-only proxy which can serve the same API on the same port, and authenticates as a user that only has access to healthz.

/cc @justinsb @micahhausler @deads2k @liggitt
/sig auth api-machinery
/milestone v1.20
/kind cleanup
/priority important-longterm