Deploy the nodejs-ex helm chart on Opensshift

Question

Pulumi · Accepted Answer

To deploy a Helm chart on an OpenShift cluster using Pulumi, you will be using the kubernetes.helm.v3.Chart resource from the Pulumi Kubernetes provider. This resource is designed to deploy Helm charts, which are packages of pre-configured Kubernetes resources.

Here's a step-by-step guide on how to create a program that will deploy the nodejs-ex Helm chart on an OpenShift cluster:

Prerequisites

Before you begin, ensure you have the following prerequisites met:

Have an OpenShift cluster up and running.
Configured your Pulumi environment to interact with your Kubernetes cluster. Usually, this means having a kubeconfig file that has the necessary credentials.
Installed Pulumi CLI and set up with desired state backend.
Installed Node.js and npm to run Pulumi TypeScript code.

You will also need to know the repository where your Helm chart is located, the chart name, and any specific configurations you want to set.

Pulumi Program

Below is a TypeScript program that uses Pulumi to deploy the nodejs-ex Helm chart to OpenShift.

import * as k8s from '@pulumi/kubernetes';

// Step 1: Initialize a Pulumi Kubernetes Provider to interact with OpenShift
// This assumes that your `kubeconfig` file is set up properly to access the OpenShift cluster
const provider = new k8s.Provider('openshift-k8s', {
    // You may specify the kubeconfig explicitly; however, if it is omitted, 
    // Pulumi automatically uses the current context from the local kubeconfig
    // kubeconfig: '<path-to-kubeconfig-file>',
});

// Step 2: Define the Helm Chart resource for nodejs-ex
// Replace `<helm-repo>` with the repository URL where the nodejs-ex chart is hosted
const nodejsExChart = new k8s.helm.v3.Chart('nodejs-ex-helm-chart', {
    chart: 'nodejs-ex',
    version: '1.0.0', // replace with the specific chart version if necessary
    fetchOpts: {
        repo: '<helm-repo>', // replace with the Helm repository URL
    },
    // You can specify namespace, values and other chart parameters here
}, { provider });

// Export the base URL for the Node.js application if applicable
// This assumes the chart exposes the Node.js application through a Service with an Ingress or Route
export const appUrl = nodejsExChart.getResourceProperty('v1/Service', 'nodejs-ex', 'status').apply(status => {
    const ingress = status.loadBalancer.ingress[0];
    if (ingress) {
        return `http://${ingress.hostname}`;
    }
    return 'Ingress not set or service not yet exposed';
});

Explanation

Provider: A Kubernetes Provider resource is used to establish the connection to the OpenShift cluster. Pulumi uses the cluster details from the kubeconfig file which should have the necessary OpenShift credentials.
Chart: The Chart resource is responsible for fetching and deploying the specified Helm chart. In this case, it references nodejs-ex. You need to replace <helm-repo> with the actual repository URL where your nodejs-ex chart is located.
Version: Specify the version of the Helm chart you want to deploy.
Export: At the end of the script, there's an example of how you might export the URL of the deployed Node.js application. This assumes that your Helm chart creates a Kubernetes Service with a public endpoint, such as through an Ingress or Route. Modify the resource names and properties to match the actual output of your Helm chart.

Replace placeholder values with actual values from your environment. Once the program is executed with pulumi up, it will deploy the nodejs-ex Helm chart to your OpenShift cluster.

Keep in mind that some Helm charts may require additional configuration, stored as key-value pairs passed through the values parameter in the Chart resource. If the nodejs-ex chart requires specific values, you would include a values object in the Chart resource configuration.

Before running the program, install the required Pulumi Kubernetes package with npm:

npm install @pulumi/kubernetes

To run the program, navigate to the directory containing the index.ts file and run the following commands:

pulumi stack init dev             # Initialize a new Pulumi stack called 'dev'
pulumi up                         # Preview and deploy changes

You'll be prompted to review the changes and input yes to apply them to your cluster. Successful execution indicates that your Node.js Helm chart has been deployed to OpenShift.