This is a Bug Report

Problem:
Broken link to UAA setup instructions http://apigee.com/about/blog/engineering/kubernetes-authentication-enterprise
according to wayback machine this was removed circa 2017

Proposed Solution:
remove link or change link to UAA github site https://github.com/cloudfoundry/uaa
Also propose updating Dex setup instructions to 2018 New Stack article by Joel Speed https://thenewstack.io/single-sign-kubernetes-command-line-experience/

Page to Update:
https://kubernetes.io/docs/reference/access-authn-authz/authentication