README.md

Episode 131 : No mo' yolo with Validating Admission Controllers

• Hosted by @ciberkleid and @pczarkowski
• 09/11/2020

Table of Contents

• 00:00:00 - Welcome to TGIK!
• 00:04:27 - Week in Review
• 00:19:50 - What are Admission Controllers?
• 00:30:57 - Validating Admission Controller webhook
• 01:14:29 - Mutating Admission Controller webhook

Week in Review

Core K8s

• 1.19.1 is out, here's the changelog
• Point releases v1.19.2/1.18.9/v1.17.12 are scheduled for September 16
• Proposal for WG Reliability
• Check out the blog post on warnings
• Steering Committee Election Update
  • Nomination/exception processes are now closed.
• KubeCon videos are now all on YouTube if you wanna catch up.

K8s and Cloud Native Ecosystem

• The Jetstack folks outline performing a live CNI migration
• Jakub Pavlik looks at Kubernetes Storage performance comparison
• CrunchyData has released a postgres operator
• Bookmark this - https://k8syaml.com/

Show Notes

Reference docs:

• https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers

Examples:

1. Validating Admissions Controller from Eric Shanks' The IT Hollow blog

   • Write-up and code repo
   • This controller is written in Python and provides a clear and simple example of the minimum controller & webhook requirements
   • Slightly modified fork (uses a cert manager & includes a kind cluster config file)

2. Mutating Admissions Controller by Paul

   • Code repo
   • This controller is written in Golang and uses ytt to manipulate the incoming request; the controller is generic and reads the specific ytt manipulations from a ConfigMap
   • Includes steps to run locally, deploy with kubectl, or deploy using helm