Helm – Kubernetes Package Manager and Installation in Local Machine

Pre-requisite: Helm, Kubernetes 

Helm is a CNCF graduate project. It is a Kubernetes package manager that simplifies the process of deploying and running applications on a Kubernetes cluster. It provides an easy way to package Kubernetes applications in charts, which can be easily deployed, installed, and updated using the Helm CLI. Helm was first created in 2015 by Deis, a company that Microsoft eventually purchased. With a wide community of contributors and users that use it to manage their Kubernetes deployments, it has since grown to be one of the most well-liked tools in the Kubernetes ecosystem.

Helm Key Features

Application deployment: Helm simplifies the deployment of complex applications by giving a single package that contains all the settings and resources required for Kubernetes. Developers can accomplish this with Helm by packaging the application as charts, which makes it simple to install and manage using the Helm CLI. By eliminating the need to manually create and manage each individual Kubernetes resource, the deployment to the Kubernetes cluster is made simple.

Distribution of the Application: Helm provides a central repository for the storage and exchange of charts. The Helm Chart Repository, which allows developers to share their charts, also makes it simple to search and install charts from a single location. To distribute charts within their organization, developers can also establish their private repository.

Application Versioning: Helm charts can be versioned, which makes it simple to go back to a previous release of an application if necessary. This assists in preventing downtime brought on by application problems or failures. Helm charts may be readily upgraded or downgraded by users, and developers can easily track changes to their applications over time by versioning them.

App Reusability: Helm charts facilitate communication and cut down on effort duplication when utilized by numerous teams and projects. This aids in creating an ecosystem of applications that anyone within the company may swiftly deploy. Developers may easily share and reuse the same chart across several projects by packaging their apps as charts with all the necessary Kubernetes resources and configurations using Helm.

Chart management: Helm allows you to create and manage charts, which are packages of pre-configured Kubernetes resources that you can deploy and manage using Helm. Charts can be versioned, shared, and reused across different environments.

Dependency management: Helm supports dependency management, which means that you can define dependencies between charts and manage them as a single application.

Release management: Helm provides a simple way to install, upgrade, and uninstall your Kubernetes applications as releases. A release is a specific instance of a chart that has been deployed to a Kubernetes cluster.

Configuration management: Helm allows you to define and manage configuration values for your Kubernetes applications, which can be passed to your charts at deployment time. This makes it easy to manage configurations across different environments.

Helm Key Concepts

• Helm CLI:  The Helm CLI is a command-line tool that enables you to install, upgrade, and manage Kubernetes applications using Helm charts. It provides a set of commands for working with charts, releases, repositories, and more.
• Helm Charts: A collection of Kubernetes resources that can be quickly deployed and managed using Helm is known as a Helm chart. Templates, values, information, and other resources needed to launch an application are frequently included in charts.
• Charts repo: A Helm chart repository is a server that hosts a collection of Helm charts. Chart repositories can be public or private, and are accessed using the Helm CLI.
• Charts.yaml: The metadata file for a Helm chart is called charts.yaml. It includes details about the chart, including its name, version, description, and dependencies.
• Templates: Helm templates are files that define Kubernetes resources with placeholders for values that can be dynamically populated at runtime. Templates are typically written in the Go templating language and enable you to create reusable, configurable resources.
• Licenses: The conditions under which a Helm chart is distributed and used are often found in the license file for that chart.
• Readme.md: The readme.md file for a Helm chart offers instructions on how to install, configure, and use the chart.
• Requirements.yaml: The prerequisites for a Helm chart are specified in the requirements.yaml file. Together with their version and other metadata, it lists the charts that are necessary for the chart to function properly.
• values.yaml: The values.yaml file contains the default values for a Helm chart. These values can be overridden at runtime to customize the chart for a specific deployment or environment.
• Releases: A Helm release is a specific instance of a chart that has been deployed to a Kubernetes cluster. Each release has a unique name and version and can be managed and upgraded independently of other releases.

So, with Helm, you can find, share, and uses software built for Kubernetes. it helps you manage complex applications so all the complex applications require a lot of dependencies lot of yaml file writing and all can be managed by Helm. It makes the sharing of applications very simple by making the application in form of charts. Easily Updates the application and Rollbacks of the application are also very easy and you can install any Kubernetes application on the cluster.

• In Helm, the application is packaged as Charts.
• And It has a Template Folder and in the template folder, you get the Yaml Files, which get deployed to the cluster.
• It has the concept of values.yaml file with which you can customize and inject the values that you required for your particular needs like name, application version, image, and all these things can be templatized.

 Helm Architecture

• Helm Repo: Helm Repo is what you add to the cluster after you install Helm on your system. It fetches the Helm charts with HELM.
• HELM: Helm will fetch the helm chart from the helm repo and converts it to a valid yaml file.
• K8’s Yaml: It converts Helm charts to valid Kubernetes (K8’s) Yaml files.
• K8’s API Server: After converting Helm charts to Yaml files then it will supply to K8’s API Server.
• Runs the App: It gets deployed and runs the application.

Steps To Install Helm

Step 1: Search for install helm on google You will get to Helm’s official site, here go to Installing Helm section-> From the Binary Releases-> Click on Release. When you click on releases you will be redirected to the official git repository of Helm, from there you can go to Installation and Upgrading-> Click on (according to your OS), let’s say Click on Windows, and after that, the downloading process automatically starts.

Step 2: After downloading the Helm windows version, you have to extract the zip file, after extraction is complete you will see this helm.exe, copy or cut the helm.exe file and make a Directory folder and paste the Helm.exe into that folder. If the directory is not set in the environment variable path folder, copy the address of that folder and search for the environment variable in your pc then go to Path and add the directory. After adding the directory in the environment variable path-> open the command prompt and search for “helm”.You will see a command prompt that will execute it. 

So, if you see responding like that this means the helm binary is installed successfully on your computer.

 The basic command which is commonly used while interacting with helm charts

• helm search: This command searches for charts in the default or specified chart repositories.
• helm install: This command installs a chart from a local file or remote repository.
• helm upgrade: This command upgrades a release to a new version of a chart.
• helm rollback: This command rolls back a release to a previous version of a chart.
• helm list: This command lists all the releases deployed on the cluster.
• helm uninstall: This command uninstalls a release and removes all the resources associated with it.
• helm package: This command packages a chart directory into a versioned chart archive.
• helm lint: This command checks a chart’s syntax and validates it against the Kubernetes API.
• helm dependency: This command manages the dependencies for a chart.