Ktharatt – Put Your Clusters to Sleep

Automate Kubernetes Cluster Naps

Ktharatt is a simple Kubernetes operator that applies sleep schedules to Karpenter-managed nodepools.

💸 The Problem

Karpenter does a great job autoscaling workloads in real-time, but it doesn’t help you scale down idle clusters during nights or weekends. Your cloud bill doesn’t sleep, even when your engineers do.

💡 The Solution

Define a SleepSchedule custom resource with a cron expression
At the defined time, Nodes are drained automatically, workloads evicted gracefully
Nodepools will not be selected for provisioning during the sleep period
When sleep ends, Nodepools wakes up and starts provisioning

🚀 Installation

helm repo add ktharatt https://riyasyash.github.io/ktharatt-charts
helm install ktharatt ktharatt/ktharatt

Once installed, create your first schedule like this:

apiVersion: schedule.ktharatt.io/v1alpha1
kind: Sleep
metadata:
  name: off-work-hours
spec:
  nodepools:
    - harness-ccm-default-spot
    - default
  timezone: Asia/Kolkata
  schedule: "00 22 * * *"
  duration: 12

---
apiVersion: schedule.ktharatt.io/v1alpha1
kind: Sleep
metadata:
  name: weekend-schedule
spec:
  nodepools:
    - harness-ccm-default-spot
    - default
  timezone: Asia/Kolkata
  schedule: "0 0 * * 6,0"
  duration: 23