Upgrading Kubernetes

Notes and requirements for NDS-413. We're talking about upgrading from Kubernetes 1.2.x to 1.4 for the beta release. This page captures the risks and benefits of upgrading each component. What version should we be running? Why? What's changed?

CoreOS
Docker
- MTU
Kubernetes
- network (calico)
- storage drivers (dynamic provisioning)
- Federation/ubernetes
- upgrade paths
- performance/bugs
- log rotation
etcd
development environment (how to spin up a dev cluster)
ansible
Qualys vulnerabilities (Curl).

CoreOS

https://coreos.com/releases/
Current stable release is 1185.5.0 (12/7)
- Docker 1.11.2
- etcd2 2.3.7

Docker

I see nothing particular in 1.12 that we care about.

MTU

https://github.com/docker/docker/issues/22028 (closed) "docker 1.10, 1.11 do not infer MTU from eth0; docker 1.9 does"
- "this was a deliberate change, and specifying the MTU is the solution for this"
https://github.com/docker/docker/issues/22297 (closed) "containers in docker 1.11 does not get same MTU as host"
- "In another PR (#18108) it was decided to drop the behavior where the mtu for the containers running on the default bridge network would be inherited from the host (there were valid concerns with that approach and @phemmer IIRC lead the discussion)"
https://github.com/docker/docker/pull/18108 (closed) "don't try to use default route MTU as container MTU"
- "Trying to use the default route's MTU as the container (bridge) MTU is a bad idea:..."