What is Helm and why you should try adopting it
Today, most companies adopt a microservices architecture that helps them run efficient development and deployment of applications. Kubernetes is one of the container orchestration tools that allows you to deploy applications by reducing complexities. It comes with several open-source tools that simplify the deployment process. Working on a single application will enable you to create Kubernetes resources for which to have to write a YAML manifest file. Each microservice can be packaged along with the required features to run.
Helm is noting but , Kubernetes’s package manager that allows developers to configure, package, and deploy applications easily to the Kubernetes cluster. Helm comes under the Kubernetes open-source project and is supported by CNCF. With Helm, you can control your Kubernetes cluster.
The below article will discuss Helm, Helm charts, its benefits, and its best practices to deploy services to Kubernetes.
What is Helm?
Every programming language comes with its package manager that allows you to get along with the software or application’s installation and maintenance. As working with Kubernetes to create and manage several services is not the only complicated part, but the complexity increases with the management of different releases. Here comes the Helm to wrap up every component within a single package and configure them as per the business needs. Helm chart is Helm’s feature that enables you to define the complete application’s architecture, which can be handled using simple commands.
Adopting Helm will be a great move for businesses to automate complex business processes. With a single click, you can install Kubernetes applications for your Dev, Staging, Test or Production environments.
Helm will help you to install and upgrade software along with their dependencies. You can easily configure the software deployments. It also allows you to fetch packages from the repositories.
Helm comes with the below functionalities:
» Helm comes with a command-line user interface to access all the Helm functionality.
» On your Kubernetes cluster runs a companion server component known as a tiller, which listens for the Helm command and manages the Kubernetes cluster’s deployment.
» The packaging format of Helms is known as Charts.
» It comes with an official curated charts repository with prepackaged charts.
» It provides an application/chart level view of the Kubernetes cluster.
» It comes with the support of the basic template and value support for Kubernetes manifest.
» It supports the installation and upgrades of charts as a whole.
» It comes with a built-in chart rollback to its previous version without going through the CI/CD pipeline again.
What is a Helm chart?
Helm packages are also known as Helm charts that combine YAML configuration files and templates, integrated into the Kubernetes cluster. Below is the basic directory structure of the Helm-
package-name/
charts/
templates/
Chart.yaml
LICENSE
README.md
requirements.yaml
values.yaml
With the help of the Helm charts, you can easily leverage the Kubernetes packages through a single CLI command. The Helm client CLI (works locally) and Helm/Tiller servers (lies on the Kubernetes cluster) are the Kubernetes client, and server-side components where the client interacts with the server changes the Kubernetes cluster. With a single CLI command, the server will get the request to install the required packages. This provides a platform for the developers to distribute the applications and the users to install that application.
The three concepts of learning Helm-
* Chart, which is a pre-configured package of Kubernetes resources.
* Release, which is a chart’s instance being deployed.
* and Repository, which is a group of charts available to all.
Benefits of Helm
Below are the reasons why Helm is getting popular among developers.
* It will help you to boost development and deployment productivity. Using Helm will allow you to deploy the test environment for the software at just one click. Considering an example, suppose you want to create a database for testing new software. Instead of installing software, creating a database, and related tables, you can just execute Helm’s install command to create the database ready for testing.
* Using Helm charts can reduce duplication and complexity. Once you create the chart, it can be reused over time and for any environment. You have to tune the Helm chart to make it available for any environment.
* Helm helps in simplifying the learning curve for the Kubernetes detailed functioning. You can even integrate the Helm within the CI/CD pipeline so that developers focus on writing codes rather than deploying those codes.
* With the help of Helm charts, you can easily override the YAML file values to define a base set. You can change the setting while installing the charts. If you are okay with the default settings, then no override is required.
* Helm chart reduces the chances of deployment errors due to incorrect config file entries or improper deployment processes.
* The Helm chart reduces the complexity of maintaining the App catalog and helps the operation teams not raise any service ticket during deployment.
Common Helm best practices
We are sharing some of the common best practices for Helm.
♠ Make sure you use the non-root containers to perform actions for production deployment. The non-root containers are executed by the users that are different from the root. Though setting a non-root container is a more complicated job than a root container. You should prefer to use a non-root containers for kubernetes like environments. You can add the securityContext section to your YAML files to make your chart work with non-root containers.
♠ You should not persist in the configuration of the application. With Kubernetes, you can easily change the deployment parameters with easy commands. If the configuration is continued, it means none of the changes would be done. While making Helm charts, make sure that the configuration can be changed easily using helm commands.
♠ You can use logging and monitoring tools to be integrated within your charts. To detect any threats at the early stage of deployment, it is essential to use monitoring tools and the right metrics tools to check the incurred cost and resources. With the proper monitoring and logging tools, you can easily handle the production workloads.
♠ It is better to have a single chart containing a single application. This chart will include the required application’s resources. A single chart can also have dependencies on other charts.
♠ Try to run your deployments from a clean setup. Else, it might get impacted by other repo settings. You can use the pre-built Docker image to create a clean environment.
♠ You can always use a generic chart for a namespace configuration.
♠ Always try to declare your repositories using an IAC tool and try to avoid a legacy chart repository.
♠ Try to avoid hardcoding the namespace and write a good output template.
♠ Try to run both upgrade and fresh install tests for your chart releases for better monitoring and testing.
Conclusion
No doubt that Helm is a powerful package manager that makes installing and managing applications on top of Kubernetes as simple and easy process.Also Helm Charts add to the experience by giving curated and tested templates to install applications.
So if you’re a developer and looking to package your application as a Kubernetes application, Helm might be the way to go. Even if you are a Devops guy trying to deploy either internal or third-party applications, you should use Helm as your packaging manager tool for Kubernetes.
Also if you are already familiar with Helm and trying to start using it, you can also refer to our article on Helm Cheatsheet, where we cover some of the commonly used helm commands for beginners.
