Deploying Helm Charts with Jenkins and Groovy: A Comprehensive Guide

Introduction:

Helm is a popular package manager for Kubernetes that makes it easy to manage, deploy, and share applications on a Kubernetes cluster. Jenkins is a popular automation server that is widely used for Continuous Integration and Continuous Deployment (CI/CD) workflows. In this blog post, we’ll explore how to use Jenkins and Groovy to deploy Helm charts to a Kubernetes cluster. We’ll start by setting up Jenkins for Helm chart deployment, then we’ll write Groovy scripts to deploy Helm charts, and finally, we’ll provide a real-world example of deploying a Helm chart with Jenkins and Groovy.

Section 1:

Setting Up Jenkins for Helm Chart Deployment To deploy Helm charts with Jenkins, we need to set up a few things first. Here are the steps to set up Jenkins for Helm chart deployment:

1. Install the Helm plugin for Jenkins: The Helm plugin allows Jenkins to communicate with a Kubernetes cluster and deploy Helm charts. You can install the Helm plugin by navigating to “Manage Jenkins” -> “Manage Plugins” -> “Available” and searching for “Helm”.
2. Install the Helm CLI on the Jenkins server: The Helm CLI is a command-line tool for managing Helm charts. You can install the Helm CLI on the Jenkins server by following the instructions on the Helm website.
3. Configure Kubernetes credentials in Jenkins: To communicate with a Kubernetes cluster, Jenkins needs to have the necessary credentials. You can configure Kubernetes credentials in Jenkins by navigating to “Credentials” -> “System” -> “Global credentials” -> “Add Credentials” and selecting “Kubernetes configuration” as the credential type. Enter the necessary information, such as the Kubernetes API server URL, the cluster certificate, and the service account token.
4. Configure Jenkins build environment: To deploy Helm charts, we need to set up the build environment in Jenkins. This involves configuring environment variables and installing necessary tools. You can do this by navigating to the Jenkins build configuration page and selecting “Environment variables” and “Build steps” as necessary.

Section 2:

Writing Groovy Scripts for Helm Chart Deployment Now that we’ve set up Jenkins for Helm chart deployment, we can start writing Groovy scripts to deploy Helm charts. Here are some examples of Groovy scripts that can be used for deploying Helm charts:

1. Install a Helm chart:

node {
  stage('Install Helm chart') {
    sh "helm install mychart --set key=value"
  }
}        

This script installs a Helm chart named “mychart” with a custom value for a key.

2. Upgrade a Helm chart:

node {
  stage('Upgrade Helm chart') {
    sh "helm upgrade mychart --set key=value"
  }
}        

This script upgrades a Helm chart named “mychart” with a custom value for a key.

3. Roll back a Helm chart:

node {
  stage('Rollback Helm chart') {
    sh "helm rollback mychart 1"
  }
}        

This script rolls back a Helm chart named “mychart” to the previous version.

Section 3:

Real-World Example of Deploying a Helm Chart with Jenkins and Groovy Let’s walk through a real-world example of deploying a Helm chart with Jenkins and Groovy. In this example, we’ll deploy the popular nginx-ingress Helm chart to a Kubernetes cluster.

1. Create a Jenkins pipeline: First, we need to create a Jenkins pipeline to deploy the Helm chart. We can do this by navigating to the Jenkins home page and selecting “New Item” -> “Pipeline” and entering a name for the pipeline.
2. Configure the pipeline: Next, we need to configure the pipeline by defining the steps to deploy the Helm chart. Here’s an example of a Jenkins pipeline script that deploys the nginx-ingress Helm chart:

pipeline {
    agent any
    environment {
        KUBECONFIG = credentials('kubernetes-config')
    }
    stages {
        stage('Checkout') {
            steps {
                git 'https://github.com/kubernetes/ingress-nginx.git'
            }
        }
        stage('Deploy Helm chart') {
            steps {
                sh "helm install ingress-nginx ./deploy/charts/ingress-nginx --namespace ingress-nginx --set controller.publishService.enabled=true --set controller.service.loadBalancerIP=${env.LB_IP}"
            }
        }
    }
}        

In this script, we first set the Kubernetes configuration using the credentials we configured earlier. We then checkout the nginx-ingress repository from GitHub. Finally, we deploy the Helm chart using the helm install command, with custom values for the controller.publishService.enabled and controller.service.loadBalancerIP parameters.

3. Trigger the pipeline: Now that the pipeline is configured, we can trigger it to deploy the Helm chart. We can do this by navigating to the pipeline and selecting “Build Now”. Jenkins will then execute the pipeline script and deploy the Helm chart to the Kubernetes cluster.

Conclusion:

In this blog post, we’ve explored how to use Jenkins and Groovy to deploy Helm charts to a Kubernetes cluster. We started by setting up Jenkins for Helm chart deployment, then we wrote Groovy scripts to deploy Helm charts, and finally, we provided a real-world example of deploying a Helm chart with Jenkins and Groovy. With these tools and techniques, you can streamline your CI/CD workflow and deploy Helm charts with ease.