Kubernetes Create LimitRange CLI Plugin

A kubectl plugin for creating LimitRange resources with specified CPU and memory limits in Kubernetes namespaces.

Overview

This plugin provides a command-line interface for easily creating LimitRange resources in your Kubernetes cluster. It extends the kubectl create command to support creating LimitRange resources directly. It supports both client-side and server-side dry runs and outputs in YAML or JSON formats for previewing the resource before creation.

Features

• Create LimitRange resources with configurable CPU and memory limits.
• Supports dry-run modes (client and server) to preview the resource without applying it.
• Outputs resource definitions in YAML or JSON format.
• Easy to use with intuitive command flags.

Installation

Ensure you have Go installed and kubectl configured on your system. Clone this repository and run:

go build cmd/kubectl-create-lr/kubectl-create-limitrange.go

Move the binary to a directory in your PATH:

mv kubectl-create-limitrange /usr/local/bin/

Run tests

go test ./pkg/cmd/... -v

Usage

Basic Example

kubectl create limitrange my-limitrange --namespace=my-namespace --max-cpu="1" --min-cpu=100m --max-memory=500Mi --min-memory=100Mi

Client-Side Dry Run

kubectl create limitrange my-limitrange --namespace=my-namespace --max-cpu="2" --dry-run=client -o yaml

Server-Side Dry Run

kubectl create limitrange my-limitrange --namespace=my-namespace --max-cpu="1" --dry-run=server -o json

No Dry Run Example

kubectl create limitrange my-limitrange --namespace=my-namespace --max-cpu="1" --min-cpu=100m --max-memory=500Mi --min-memory=100Mi

Command Flags

• --max-cpu: Maximum CPU limit for containers.
• --min-cpu: Minimum CPU limit for containers.
• --default-cpu: Default CPU limit for containers.
• --default-request-cpu: Default CPU request for containers.
• --max-memory: Maximum memory limit for containers.
• --min-memory: Minimum memory limit for containers.
• -n, --namespace: Namespace for the limitrange resource (shorthand for --namespace).
• --dry-run: Dry-run mode (client or server).
• -o, --output: Output format (yaml or json).

Example Commands

• Create a limitrange with CPU and memory limits:

  kubectl create limitrange my-limitrange --namespace=my-namespace --max-cpu="1" --min-cpu=100m --max-memory=500Mi --min-memory=100Mi

• Client-side dry-run:

  kubectl create limitrange my-limitrange --namespace=my-namespace --max-cpu="2" --min-cpu=500m --dry-run=client -o yaml

• Server-side dry-run:

  kubectl create limitrange my-limitrange --namespace=my-namespace --default-cpu=500m --default-request-cpu=200m --dry-run=server -o json

Requirements

• Go 1.24 or later.
• kubectl configured on your system.

Contributing

Feel free to contribute by submitting issues or pull requests. Any help to enhance the functionality or add new features is welcome!