Review “Resource metrics” pipeline

[sftim]

Page to review
https://kubernetes.io/docs/tasks/debug-application-cluster/resource-metrics-pipeline/ mentions Kubernetes v1.8
Review this page, removing references to Kubernetes versions that are earlier than what's supported, and revising wording to suit.

Why is this needed
The documentation usually can and should assume that the reader is running a version of Kubernetes that is at least as new as the oldest version still supported.

Comments
/kind cleanup

[miteshskj]

@sftim - Is the intent to remove all references to versions (eg: feature foo was introduced in 1.x) or just where it's a requirement (eg: feature foo works with 1.+ or minimum version required is 1.x)? where 1.x is an unsupported version.

[aimeeu]

/priority important-longterm

[sftim]

@miteshskj All references to unsupported versions. Anyone interested in history would, I think, be more likely to look at release notes or Git commit logs anyway.

Imagine that all pages start with “The following text assumes your cluster is running Kubernetes v1.12 or newer” (v1.12 because right now v1.12 is the oldest supported version), and that's why you can omit information about older versions.

However one possible exception, feature state. Ingress is in beta and has been since v1.1
The feature-state shortcode for Ingress correctly lists v1.1 as the version it went beta in. That'll be true forever, no matter how many later releases come out.
If / when Ingress goes GA then the feature-state on that page will update, of course.

[miteshskj]

/assign