karpenter-generate

This is a simple CLI tool to generate AWS Karpenter Custom Kubernetes Resources (Nodepool & EC2NodeClass) from AWS EKS Managed Nodegroup information. It will merge similar CRDs if they are equal which reduce number of generated resources. The generated resources can be stored in as a yaml manifest file or can be directly applied to the cluster.

Warning

The tool can only generate v1beta resources for Karpenter on AWS. Compatible with Karpenter v.0.32.0 onwards

Example Usage

For All Managed Nodegroups

karpenter-generate --cluster <Cluster_Name> --karpenter-nodegroup fargate (If Karpenter is deployed on Fargate)

## OR ##

karpenter-generate --cluster <Cluster_Name> --karpenter-nodegroup <Managed Node Group Name>

For specific Managed Nodegroup

To generate Karpenter Custom Resources for a specific Managed Nodegroup.

karpenter-generate --cluster <Cluster_Name> --karpenter-nodegroup fargate --nodegroup <Managed_Nodegroup_Name>

Prerequisites

• Propely Configured AWS CLI

Installation

MacOS & Linux

Use Homebrew and run following command.

brew tap punkwalker/tap
brew install karpenter-generate

Manually (Linux/Windows)

Downloaded archive file from release artifacts. Download the archive file from relase page according to the Architecture of your machine

OS	Arch	Download
Linux	AMD64/x86_64	Link
	ARM64	Link
Windows	AMD64/x86_64	Link
	ARM64	Link

After downloading the archive, extract it and copy the binary/executable to /usr/local/bin for Linux. For Windows, run the karpenter-generate.exe from extracted folder.

Using generated CRDs

1. Install Karpenter

   Follow instructions from Karpenter installation and install Karpenter v0.32.0+. (Recommended: Deploy Karpenter on Fargate)

2. Generate Custom Resources using karpenter-generate

   Run following commands to generate the resources and store in a file.

   $ karpenter-generate --cluster <Cluster_Name> --karpenter-nodegroup fargate > karpenter-resources.yaml
   

3. [Optional] Review generated resources or make any changes if desired.

4. Create resources

   Run following command to create resources using YAML file

   $ kubectl apply -f karpenter-resources.yaml
   

5. Scale down Managed Node Groups

   Once the resources are created successfully,

   • Taint Managed Node Group with following taint to evict pods:

     Key: karpenter-migration
     Value: true
     Effect: NoExecute
     
     ## OR Individual node can be tainted using below command ##
     
     $ kubectl taint node <node_name> karpenter-migration=true:NoExecute
     

   • Keep following karpenter pod logs to check if karpenter is scaling the nodes for evicted pods.
   • After all evicted pods are successfully scheduled on Karpneter nodes. Scale down Managed Node Groups to 0.

Help

karpeter-generate  --help

Description:
  A CLI tool to generate Karpenter Custom Resources such as
  Nodepools and EC2NodeClass from details of EKS Managed Nodegroup

Usage:
  karpenter-generate --cluster <Cluster Name> --karpenter-nodegroup <Karpenter Nodegroup Name> [flags]

Available Commands:
  version     Print the version and build information for karpenter-generate

Flags:
  --cluster string               name of the EKS cluster 
  --karpenter-nodegroup string   name of the EKS managed nodegroup running Karpenter deployment or Fargate
									 
Optiona Flags:
  --nodegroup string   name of the EKS managed nodegroup 
                       (default: all the nodegroups expectthe one running Karpenter)
  --region string      region of EKS cluster, overrides AWS CLI configuration/ENV values 
                       (default: AWS CLI configuration)
  --profile string     use the specific profile from your credential file 
                       (default: AWS CLI configuration)
  --output string      output format (yaml or json)
					   (default: yaml)
  -h, --help           help for karpenter-generate
	`

Contributing

Contributions are welcome! If you encounter any issues or have suggestions for improvements, please follow these steps:

1. Fork the repository.
2. Create a new branch for your feature or bug fix.
3. Make your changes and commit them with descriptive commit messages.
4. Push your changes to your forked repository.
5. Submit a pull request to the main repository.

Please ensure that your code adheres to the project's coding standards and includes appropriate tests.

License

This tool is licensed under the License Name License. See the LICENSE.md file for more information.