add buffer chart example

[colearendt]

TODO:

• revisit defaults
• strip out unnecessary elements
• add extraObjects or helpers for deploying priorityClasses (although that could also be considered to be at the wrong "level" / hierarchy)
• add ci / testing / linting

[jonlinca]

Thanks for incorporating this. As a reference, this is how we implemented ours. The numbers aren't as important as the globalDefault

# priority.yaml

apiVersion: scheduling.k8s.io/v1
kind: PriorityClass
metadata:
 name: placeholder
value: 0
preemptionPolicy: Never
globalDefault: false
description: 'placeholder'
---
apiVersion: scheduling.k8s.io/v1
kind: PriorityClass
metadata:
 name: normal
value: 1
preemptionPolicy: Never
globalDefault: true # default
description: 'normal'

# placeholder.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: placeholder
spec:
  replicas: 4 # this is implementation specific
  selector:
    matchLabels:
      app: placeholder
  template:
    metadata:
      labels:
        app: placeholder
  spec:
    terminationGracePeriodSeconds: 0 # important
    priorityClassName: placeholder # important
    nodeSelector:
      rsc: content # this is implementation specific
    containers:
    - image: k8s.gcr.io/pause
      name: placeholder
      resources:
        requests:
          memory: 1024M

References:

• https://itnext.io/how-to-faster-node-scale-your-kubernetes-cluster-2c988c7c7d08
• https://learnk8s.io/kubernetes-autoscaling-strategies