What is Helm

• Chart: folder with Chart.yaml + templates/ + values.yaml
• Release: deployed instance of chart (namespaced)
• Values: override defaults per environment
• Helm Hub / Artifact Hub: public chart registry
• OCI support: Helm 3.8+ push charts to OCI registries (ghcr, ECR)

# Install chart
helm install my-release bitnami/postgresql \
  --set primary.persistence.size=100Gi \
  --set auth.postgresPassword=secret

# values-prod.yaml override
helm upgrade my-release bitnami/postgresql \
  -f values-prod.yaml

• K8s Operator
• GitOps
• ArgoCD

Helm Charts are the core component of Helm, serving as a collection of files that describe a related set of Kubernetes resources. A Chart is essentially a directory that contains all the necessary YAML files, including templates and configuration values, to deploy an application on Kubernetes. Each Chart usually includes:

• Chart.yaml: Contains metadata about the Chart, such as its name, version, and description.
• templates/: A folder that holds template files which define the Kubernetes resources (like Deployments, Services, etc.) that will be created.
• values.yaml: This file provides default configuration values that can be overridden by users during installation.

By using Charts, developers can manage complex applications with ease, encapsulating multiple Kubernetes resources within a single package. This encapsulation allows for easier version control and sharing across teams.

Helm provides a command-line interface that simplifies the management of Kubernetes applications. Below are some of the most commonly used Helm commands:

• helm repo add REPO_NAME REPO_URL: Adds a new Helm repository to your local configuration.
• helm search repo KEYWORD: Searches for Charts in the added repositories that match the specified keyword.
• helm install RELEASE_NAME CHART: Installs a Chart into your Kubernetes cluster, creating a new release.
• helm upgrade RELEASE_NAME CHART: Upgrades an existing release to a new version of a Chart.
• helm uninstall RELEASE_NAME: Removes a release from your Kubernetes cluster.

For example, to install the popular Nginx Ingress Controller using a Helm Chart, you would run:

This command will deploy the Nginx Ingress Controller with the release name 'my-nginx-ingress'. You can further customize the installation by providing a custom values.yaml file:

By leveraging these commands, you can efficiently manage applications on your Kubernetes cluster.

When evaluating tools for managing Kubernetes configurations, Helm and Kustomize frequently come into play. Both serve distinct purposes and have their strengths and weaknesses.

Helm is primarily a package manager, allowing users to deploy and manage applications as Charts. It simplifies the installation process and offers features like versioning, templating, and dependency management. However, it introduces complexity with templating and requires a learning curve to understand how to create and manage Charts effectively.

Kustomize, on the other hand, focuses on customizing raw Kubernetes manifests. It does not package resources like Helm but instead allows users to overlay configurations on top of existing YAML files. This approach is simpler for straightforward configurations and doesn't require the creation of a package. Kustomize is part of the Kubernetes ecosystem and can be used natively with kubectl apply -k.

Here’s a quick comparison:

• Use Case: Helm is better for deploying complex applications with multiple dependencies, while Kustomize is more suited for simple customization of existing configurations.
• Templating: Helm uses a templating engine, allowing for dynamic configuration, whereas Kustomize strictly relies on overlays.
• Learning Curve: Helm has a steeper learning curve due to its packaging and templating features, while Kustomize is more intuitive for users familiar with raw YAML.

Choosing between Helm and Kustomize ultimately depends on your specific needs and the complexity of your Kubernetes applications.