Node Problem Detector custom scripts

Adding our own scripts to https://github.com/kubernetes/node-problem-detector and sharing them in case you might find those handy for you use cases.

The scripts details can be found in /config/plugin/ but ultimately, they are:

launch-config-drift: a way to check if your instances launch template has diverged from your asg launch template
spot-termination: uses the meta-data/spot/instance-action endpoint to check EC2 Spot Instance interruption notice
local-dns-resolver: checks the response status value received (if any) from the local dns resolver ip
upstream-dns-resolver: check if we receive an IPv4 address for a given A record.
uptime: every 5 seconds, checks if the information detailing how long the system has been on since its last restart is acceptable (to us the threshold being 604800 seconds)

Notes

July 2024 - The custom node problem detector image is now stored in the uswitch/node-problem-detector repository on Quay.