This repo contains 2 implementations of k8s scheduler examples. The rules of scheduling pods is quite simple, but they can show you how to create your own schedulers in k8s.

1. A standalone scheduler server: hawq-scheduler
2. An example of second scheduler in k8s 1.11, using extenders: hawq-scheduler-extender

Hawq scheduler is a server that can run outside of k8s or in a container in k8s.

Hawq scheduler use client-go to get the pod that use hawq-scheduler as it's schedulerName. Here is an example for creating a pod using hawq-scheduler:

apiVersion: v1
kind: Pod
metadata:
  name: hawq-cluster-1-master-0
spec:
  containers:
    - name: hawq-master
      image: hawqbeijing/hawq_proxy:vcheng
  schedulerName: hawq-scheduler

With this type of scheduler, k8s has no idea if the scheduler is running or not, or even does not know it exist.

hawq scheduler extender can run with a registered k8s scheduler, it is set with a config file. Since k8s has moved scheduler extender from plugin to cmd recently, there is few examples on how to create a scheduler with extender. Well, this repo is what you can refer to :)

Read this link for more details