Kubernetes DNS Horror Stories - And How to Avoid Them
CNCF [Cloud Native Computing Foundation] via YouTube
Overview
Syllabus
Intro
Datadog
Challenges
What we did not expect
Outline
How it works (by default)
Accessing DNS
Theory: Scenario 2
In practice
Let's disable IPv6!
What triggers IPv6?
We use Go a lot
Subtle difference
CGO implementation
Coredns Autopath
Node-local-dns
Initial state
Pod A deleted
Source port reuse
Mitigation #2
Coredns getting OOM-killed
Proportional autoscaler
Staging fright on AWS
Upstream DNS issue
Something weird
DNS is broken for a single app
Sometimes it's not DNS
Our DNS setup
Conclusion • Running Kubernetes means running DNS DNS is hard, especially at scale
Taught by
CNCF [Cloud Native Computing Foundation]