RedSwitches
7 min read · Aug 7, 2024
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Kubernetes (also known as K8) is an open-source system designed to automate the deployment, scaling, and management of applications in containers. With the increasing complexity of Kubernetes containerized applications, deploying them manually can be cumbersome and lead to errors.
Helm, a package manager for Kubernetes, simplifies deployment and management of applications.
It automates the creation, packaging, configuration, and deployment of Kubernetes applications by combining the configuration files into a single reusable package.
In this tutorial, we will discuss Helm in detail. We will discuss the benefits and capabilities of the package manager and then see how Helm charts help speed up application deployment.
If Kubernetes were an operating system, Helm would be its package management, just as Ubuntu uses APT and CentOS uses YUM.
Helm deploys packaged applications to Kubernetes using charts, which bundle all pre-configured application resources and versions into a single, manageable package.
Helm’s straightforward CLI commands make installing, upgrading, fetching dependencies, and configuring Kubernetes installations easy. The best part is that you can discover software packages in repositories or generate custom bundles.
Given the complexity and versatility, managing Kubernetes clusters can be tricky. Helm simplifies this by automating the maintenance of complex YAML files by packaging them into charts and deploying them to a Kubernetes cluster.
This process smoothens the learning curve and resolves any dependency-related problems.
Helm groups all Kubernetes resources (Pods, Deployments, Services, etc.) for an application into a single unit called a Helm chart. This Helm chart streamlines an easy deployment and upgradation.
Helm enforces a consistent way to structure application deployments. This reduces errors and makes deployments easier to understand and manage for teams across different environments (development, staging, production).
Helm charts can also be reused in various environments by simply adjusting configurations within the chart. This ensures consistency and saves time when deploying across a workflow.
Helm keeps a versioned record of each chart installation and change. Using simple commands, users can simply roll back to a prior version or upgrade to a newer version. This makes managing deployments more reliable and less risky.
Helm provides a range of capabilities designed to simplify and enhance the management of Kubernetes applications.
Helm allows users to easily deploy and test environments, which speeds up the transition from development to testing and production.
Some of the capabilities of Helm are:
Helm packages applications into charts (Collections of files that describe a related set of Kubernetes resources). These can be shared and reused.
Helm allows for the deployment of complex applications with a single command. It also tracks versions of the releases, making it easy to upgrade applications and find the status of the release.
Helm uses values files to manage configuration settings for charts. These files allow users to override default settings, making customizing deployments for different environments easy.
Helm makes managing multiple environments (e.g., development, staging, production) easy by using different values files for the same chart.
Helm can be integrated into CI/CD pipelines to automate the deployment and management of applications. This enables continuous delivery practices and improves deployment consistency.
Helm integrates with Kubernetes’ role-based access control (RBAC) and other security policies, ensuring that deployments adhere to organizational security standards.
Helm simplifies managing applications in Kubernetes clusters by introducing the concept of Helm charts.
Helm charts are packages comprising YAML files and templates that translate into Kubernetes manifest files. They are designed for reusability across different environments, minimizing complexity and redundancy.
Components
A Helm chart typically consists of three main parts:
chart.yaml
This file defines metadata about the chart, such as its name, version, dependencies on other charts, and a brief description.
Templates
These are YAML templates that contain the actual Kubernetes resource manifests. Helm uses these templates to generate the final deployment manifests during installation.
values.yaml (Optional)
This file defines configuration values that can be used to customize the application deployment. You can provide different values files for different environments (development, staging, production) to tailor the deployment to each environment’s needs.
The following table summarizes the components of the Helm chart.
The working of Helm charts is based on three main concepts:
Chart: A preconfigured template for Kubernetes resources.
Release: A chart deployed to a Kubernetes cluster using Helm.
Repository: Publicly available Charts.
Let us discuss these in detail.
Helm chart repositories function like software package repositories. They store Helm charts, making them easily discoverable and reusable by the community.
When working with them, the first step involves searching for existing Helm charts in public repositories or in local chart stores.
Helm offers two primary ways to search for charts:
- helm search hub
- helm search repo
The helm search hub command searches the Artifact Hub, a central repository that aggregates charts from various sources. It provides a comprehensive search across a vast collection of charts.
The helm search repo command searches Helm chart repositories added locally to the Helm client using the helm repo add command. These repositories can be public or private.
Once you search the repositories using the above commands, available charts appear in the search results. To narrow down your query, add a specific search term.
For instance:
# helm search hub wordpress
Once you have the desired chart, you use the Helm CLI to install it onto your Kubernetes cluster.
Execute the following command to install the chart.
# helm install <release name> <chart name>
Here,
<release name>: This is a unique name assigned to the new application deployment.
<chart name>: This specifies the name of the Helm chart to be used.
Finally, the application will be installed using the Helm charts and is called Release.
Helm releases are straightforward to manage and roll back if needed to undo any undesired changes.
Helm is a critical Kubernetes tool, streamlining deployment complexities with its robust capabilities. Its ability to manage charts and releases simplifies the orchestration of applications across clusters, offering flexibility and scalability.
Whether configuring new installations or rolling back changes, Helm’s efficiency in handling Kubernetes resources ensures smoother operations and enhances overall deployment workflows.
Q. What is Helm?
Helm is a tool that streamlines creating, managing, and deploying applications on Kubernetes. It is essentially a packaging format for Kubernetes resources, making deploying applications on a Kubernetes cluster easier.
Q. How does Helm work?
Helm allows users to define and package their Kubernetes resources as a chart package. This package includes all the necessary configuration files and metadata to deploy the application on a Kubernetes cluster with a single command.
Q. What are Helm Charts?
Helm Charts are the collection of files that define a Kubernetes application. They contain pre-configured Kubernetes resources, such as deployment configurations, services, and ingress rules, packaged in a standardized format.
Q. Why is Helm beneficial for deploying applications?
Helm simplifies the process of deploying complex applications on Kubernetes clusters. Providing a streamlined packaging format and default configuration values enables users to deploy and manage applications quickly.
Q. How can Helm be used for deploying Docker images?
Helm can be used to deploy applications that are packaged as Docker images. Users can specify the Docker image information and other configurations in the Helm Chart to orchestrate the deployment.
Q. What is the process of installing Helm?
The Helm installation involves downloading and installing the Helm binary on your machine, which serves as the client for interacting with the Helm server. Once installed, you can start creating and deploying applications using Helm commands.
Q. How can Helm Charts be upgraded?
To upgrade Helm Charts, users can use the helm upgrade command, which allows them to update the existing deployment with new configurations, versions, or settings. This helps in maintaining and evolving applications over time.
Q. How does Helm utilize the values file and templates Directory?
Helm uses the values file to store default values that can be customized for different deployments. The templates Directory Contains the templates written in Golang, which are combined with the configuration values from the values file to generate Kubernetes manifests. This process allows for flexible and consistent deployment across K8s clusters with a single package.
Q. Can Helm manage dependencies from multiple sources and cloud providers?
Yes, Helm can manage dependencies from multiple sources, including cloud providers and other external repositories. By running the helm dependency update command, Helm can fetch and update these dependencies for a single chart, ensuring all required components are up-to-date and compatible. This is particularly useful for managing complex applications that rely on various source projects.
Q. How can I monitor and roll back releases using Helm?
You can monitor the status of your Helm releases using the Helm status command, which provides detailed information about the current state of your deployments. If needed, you can roll back to a previous release easily.
