Helm is a powerful package manager for Kubernetes that simplifies the deployment and management of applications. It allows you to define, install, and upgrade even complex Kubernetes applications with ease. Whether you’re a seasoned Helm user or just getting started, this Helm cheatsheet will provide you with a quick reference guide, including definitions and practical examples, to streamline your Kubernetes operations.
What is Helm?
Helm is a package manager for Kubernetes that streamlines the process of managing, installing, and upgrading applications in a Kubernetes cluster. It uses packages called Helm Charts, which are collections of YAML files defining Kubernetes resources and configurations. Helm simplifies complex deployment scenarios and helps maintain consistency across environments.
Basic Helm Commands
Here are some fundamental Helm commands you’ll frequently use:
helm install
Installs a Helm Chart into your Kubernetes cluster.
helm install my-release ./my-chart
helm upgrade
Upgrades an existing release to a new version.
helm upgrade my-release ./my-new-chart
helm uninstall
Uninstalls a release and removes all associated resources.
helm uninstall my-release
helm list
Lists all releases in the cluster.
helm list
Working with Helm Charts
Helm Charts are essential in Helm, as they define what will be deployed in your Kubernetes cluster. Here’s how you work with Helm Charts:
Creating a Helm Chart
Create a new Helm Chart structure with the create command:
helm create my-chart
Installing a Helm Chart
Install a Helm Chart into your cluster using helm install:
helm install my-release ./my-chart
Upgrading a Helm Chart
Upgrade an existing release with a new chart version:
helm upgrade my-release ./my-new-chart
Uninstalling a Helm Chart
Uninstall a release and remove its resources:
helm uninstall my-release
Customizing Helm Releases
Helm allows you to customize releases using various methods:
Values Files
Customize Helm Chart values by providing a values file:
helm install my-release ./my-chart -f my-values.yaml
Templates
Use Helm templates to generate Kubernetes manifests:
helm template ./my-chart
Advanced Helm Usage
Take your Helm skills to the next level with advanced features:
Helm Repositories
Add and manage Helm repositories for easy access to charts:
helm repo add stable https://charts.helm.sh/stable helm repo update
Hooks
Utilize Helm hooks to run specific actions during the Helm life-cycle:
hooks: - name: my-hook events: ["pre-install"] ...
Rollbacks
Rollback to a previous release version if an upgrade goes wrong:
helm rollback my-release 1
Conclusion
Helm is an indispensable tool for Kubernetes administrators and developers, making it easier to manage complex applications and their configurations. This cheatsheet should serve as a handy reference, whether you’re installing your first Helm Chart or diving into more advanced features like hooks and rollbacks. Helm empowers you to deploy and manage Kubernetes applications efficiently, contributing to a more streamlined and scalable Kubernetes infrastructure.