Introduction
Kubernetes, with its robust container orchestration capabilities, has become the de facto platform for deploying and managing containerized applications. As organizations embrace cloud-native architecture, the need for dynamic and efficient scaling of workloads becomes paramount.
Enter Kubernetes Karpenter, an innovative tool that simplifies and automates the process of scaling workloads, enabling developers to focus on building applications rather than worrying about infrastructure management.
In this blog post, we’ll explore Kubernetes Karpenter, its features, benefits, and how it streamlines autoscaling in Kubernetes clusters.
What is Kubernetes Karpenter?
Kubernetes Karpenter is an open-source, community-driven project designed to enhance the scaling capabilities of Kubernetes. It’s built to handle the complexities of managing compute resources efficiently while ensuring optimal utilization and cost-effectiveness. Karpenter operates as a Kubernetes controller, extending Kubernetes’ Horizontal Pod Autoscaler (HPA) by automating the scaling process and implementing more intelligent scaling strategies.
Features and Benefits
Intelligent Autoscaling: Kubernetes Karpenter analyzes historical workload patterns, resource usage, and cluster metrics to make informed decisions about scaling. This intelligence helps in preventing over-provisioning, reducing costs, and optimizing resource allocation.
Resource Packets: Karpenter introduces the concept of “Resource Packets,” which enables fine-grained control over the resource allocation for a group of related pods. This feature ensures that pods sharing the same resource requirements can be packed together efficiently, improving cluster utilization.
Cluster Efficiency: The tool optimizes cluster utilization by dynamically packing pods into nodes, even those with low resource requirements. This helps to maximize the number of workloads a cluster can support, reducing the need for extensive infrastructure.
Spot Instance Support: Karpenter allows you to utilize spot instances from cloud providers, taking advantage of cost savings while maintaining resilience through intelligent workload placement.
Node Maintenance Tolerance: It gracefully handles node terminations due to maintenance, ensuring minimal disruption to running workloads.
Customizable Scaling Strategies: Karpenter is highly configurable, allowing you to define custom scaling strategies based on your specific application requirements.
How Kubernetes Karpenter Works
Karpenter operates as a Kubernetes custom controller, continuously monitoring the cluster’s state and analyzing the resource utilization metrics. When it identifies a need to scale, it utilizes the HPA to create or delete pods to meet the desired scaling requirements. The intelligence behind Karpenter lies in its ability to make these scaling decisions smarter, considering historical usage patterns and resource packing to optimize the cluster’s efficiency.
Getting Started with Kubernetes Karpenter
- Installation: Kubernetes Karpenter can be installed as a Kubernetes custom controller. Users can deploy it via YAML manifests or use package managers like Helm or Kustomize.
- Configuration: After installation, Karpenter can be configured using CRDs (Custom Resource Definitions). This allows users to define custom scaling strategies, resource packets, and other parameters as per their requirements.
- Observability: Karpenter provides metrics and logs that give insights into its scaling decisions and resource allocation, making it easier to monitor and troubleshoot the scaling behavior.
Installation
- Set environment variables
export KARPENTER_VERSION=v0.29.2
export AWS_PARTITION="aws" # if you are not using standard partitions, you may need to configure to aws-cn / aws-us-gov
export CLUSTER_NAME="${USER}-karpenter-demo"
export AWS_DEFAULT_REGION="us-west-2"
export AWS_ACCOUNT_ID="$(aws sts get-caller-identity --query Account --output text)"
export TEMPOUT=$(mktemp)
2. Install Karpenter Helm Chart in Cluster
# Logout of helm registry to perform an unauthenticated pull against the public ECR
helm registry logout public.ecr.aws
helm upgrade --install karpenter oci://public.ecr.aws/karpenter/karpenter --version ${KARPENTER_VERSION} --namespace karpenter --create-namespace \
--set serviceAccount.annotations."eks\.amazonaws\.com/role-arn"=${KARPENTER_IAM_ROLE_ARN} \
--set settings.aws.clusterName=${CLUSTER_NAME} \
--set settings.aws.defaultInstanceProfile=KarpenterNodeInstanceProfile-${CLUSTER_NAME} \
--set settings.aws.interruptionQueueName=${CLUSTER_NAME} \
--set controller.resources.requests.cpu=1 \
--set controller.resources.requests.memory=1Gi \
--set controller.resources.limits.cpu=1 \
--set controller.resources.limits.memory=1Gi \
--wait
To check Karpenter is running you can check the Pods, Deployment and Service are Running.
kubectl get pods --namespace karpenter
output:
NAME READY STATUS RESTARTS AGE karpenter-75f6596894-pgrsd 1/1 Running 0 48s karpenter-75f6596894-t4mrx 1/1 Running 0 48s
Conclusion
Kubernetes Karpenter brings a powerful set of features to the table, making autoscaling in Kubernetes more efficient, cost-effective, and intelligent. By leveraging historical usage patterns and optimizing resource allocation, Karpenter streamlines the process of managing compute resources, allowing developers to focus on building and deploying applications with confidence.
As cloud-native workloads continue to grow, Kubernetes Karpenter proves to be a valuable addition to the Kubernetes ecosystem, helping organizations unlock the full potential of their Kubernetes clusters while driving resource efficiency and cost savings. Embrace Kubernetes Karpenter today and take your Kubernetes scaling to the next level!
REFERENCES
https://karpenter.sh/v0.5.5/getting-started/
https://www.replex.io/blog/kubernetes-in-production-best-practices-for-cluster-autoscaler-hpa-and-vpa
https://aws.amazon.com/blogs/aws/introducing-karpenter-an-open-source-high-performance-kubernetes-cluster-autoscaler/
https://blog.sivamuthukumar.com/karpenter-scaling-nodes-seamlessly-in-aws-eks
https://towardsdev.com/karpenter-vs-cluster-autoscaler-dd877b91629b
https://www.infoq.com/news/2022/01/karpenter-kubernetes-autoscaler/
https://ec2spotworkshops.com/karpenter/050_karpenter/install_karpenter.html
