Scalable Human Blog

Welcome, dear readers! Today, we’ll delve into the world of Kubernetes Helm, a powerful package manager that has transformed the way we deploy and manage applications on Kubernetes clusters. In this post, we’ll explore the history of Helm, discuss its benefits and drawbacks, walk through the general setup process, and examine some common Helm commands. So, let’s set sail and navigate the waters of Kubernetes Helm together!

A Brief History of Kubernetes Helm

Helm, often referred to as the “package manager for Kubernetes,” originated in 2015 as a project by Deis, which was later acquired by Microsoft. Helm quickly gained traction within the Kubernetes community for its ability to simplify the deployment and management of applications. Now maintained by the Cloud Native Computing Foundation (CNCF), Helm has become an essential tool in the Kubernetes ecosystem.

Benefits of Using Helm

1. Simplified deployment: Helm streamlines the deployment process by packaging Kubernetes resources into easily distributable units called “charts.”
2. Version control: Helm charts support versioning, allowing you to manage and track different releases of your applications.
3. Reusability: Helm charts can be templated and parameterised, promoting reusability and reducing redundancy across multiple environments.
4. Extensive community support: Helm’s popularity means you can find a vast repository of pre-built charts for common applications, saving time and effort.

General Setup Steps

1. Install the Helm CLI: Download and install the Helm command-line interface (CLI) on your local machine.
2. Configure your Kubernetes cluster: Ensure your Kubernetes cluster is up and running, and your kubectl context is set correctly.
3. Add repositories: Add the desired chart repositories, like the official Helm repository or any custom repositories.
4. Deploy applications: Install applications using the helm install command, referencing the desired chart from the repositories.

General File Structure and Purpose

When creating a Helm chart, you’ll find a standard file structure that helps organize your application’s resources and configurations. Let’s take a look at this structure and the purpose of each file:

1. Chart.yaml: This is the main metadata file that contains information about the chart, such as its name, version, description, and any dependencies.
2. values.yaml: This file holds default configuration values that can be overridden during chart installation or upgrade. It allows for customization and parameterization of the chart.
3. templates/: This directory contains the Kubernetes resource templates, defined using the Go template language. These templates reference the values from values.yaml and are rendered into the actual Kubernetes resources during chart installation or upgrade.
   • templates/deployment.yaml: Describes a Deployment resource for managing the application’s replica sets and rolling updates.
   • templates/service.yaml: Describes a Service resource for exposing the application to the network.
   • templates/ingress.yaml: (Optional) Describes an Ingress resource for managing external access to the application.
   • templates/configmap.yaml: (Optional) Describes a ConfigMap resource for managing application configuration data.
   • templates/secret.yaml: (Optional) Describes a Secret resource for managing sensitive data, like API keys or credentials.
4. charts/: (Optional) This directory contains any subcharts or dependencies, which are other Helm charts that can be included as part of the current chart.
5. templates/tests/: (Optional) This directory holds test definitions that can be run against the deployed release to verify its functionality.
6. templates/NOTES.txt: (Optional) A plain text file that can include helpful information or instructions for users, displayed after the chart is installed.
7. .helmignore: (Optional) Similar to a .gitignore file, it lists files and directories that should be excluded from the chart package.

Common Helm Commands and Their Purposes

1. helm install: Deploy a new release of an application using the specified chart.
2. helm upgrade: Update an existing release with a new version or configuration.
3. helm rollback: Roll back a release to a previous version.
4. helm list: Display a list of deployed releases.
5. helm search: Search for available charts in the repositories.
6. helm repo: Manage your chart repositories, including adding, updating, and removing them.
7. helm uninstall: Remove a release from your Kubernetes cluster.

Final Note

In this blog post, we’ve navigated the waters of Kubernetes Helm, exploring its history, benefits, and drawbacks. We’ve also outlined the general setup process and examined some common Helm commands. Helm has proven to be an invaluable tool for simplifying application deployment and management in the Kubernetes ecosystem. As you continue your Kubernetes journey, remember to consider Helm as a trusted companion to streamline your deployment process and bolster your application management capabilities. Happy sailing!

📚 Further Reading & Related Topics

If you’re working with Kubernetes and looking to streamline your deployments, these related articles will provide valuable insights:

• Spring Boot and Docker: Containerizing Your Application – Learn how to containerize your Spring Boot applications effectively, a crucial step before managing deployments with Helm.

• Unleashing the Power of Customization: Maven Builds with Plugins and Profiles – Discover how build customization plays a role in optimizing your Kubernetes deployments, ensuring seamless integration with CI/CD pipelines.