Deploy the stateless helm chart on Opensshift

Question

Pulumi · Accepted Answer

Deploying a stateless Helm chart on OpenShift can be accomplished using Pulumi with the Kubernetes provider. Pulumi allows you to define infrastructure as code using familiar programming languages such as TypeScript.

To use Pulumi for deploying a Helm chart to an OpenShift cluster, you'll need to set up some prerequisites:

An OpenShift cluster where you have permissions to deploy applications.
kubectl configured to interact with your OpenShift cluster.
Helm CLI installed on your machine to help in identifying the correct chart and its configurations.
Pulumi CLI installed and set up to manage your infrastructure.

Below is a program written in TypeScript, using Pulumi to deploy a stateless Helm chart to an OpenShift cluster. This program assumes you have a Helm chart available and that Pulumi has access to your cluster via a kubeconfig file.

The kubernetes package provides a helm.v3.Chart class which represents a Helm chart in a given repository. When you create an instance of this class, Pulumi will ensure that the Kubernetes resources defined by the Helm chart are deployed to your cluster in the desired state.

import * as kubernetes from "@pulumi/kubernetes";

// The name of your Helm chart, the version, and any custom values you wish to provide
const chartName = "my-stateless-app";
const chartVersion = "1.0.0";
const chartValues = {
    replicaCount: 3 // Example of setting the replica count for the deployment
};

// Create a Helm chart instance 
const helmChart = new kubernetes.helm.v3.Chart(chartName, {
    chart: chartName,
    version: chartVersion,
    values: chartValues,
    // Optionally specify the namespace where you want your Helm chart to be deployed
    // If omitted, the chart will be deployed to the default namespace
    namespace: "my-namespace"
}, {
    // Pulumi uses the current context in your kubeconfig by default. 
    // You can also point Pulumi to the right context corresponding to your OpenShift cluster explicitly.
    provider: new kubernetes.Provider("openshift", { kubeconfig: "<your-kubeconfig-content>" }),
});

// Export the resources created by the Helm chart
export const resources = helmChart.resources;

This program creates a Chart resource that represents the deployment of the specified Helm chart. Here's a breakdown of what's happening in the code:

We import the @pulumi/kubernetes package which gives us the classes and functions we need to interact with Kubernetes resources.
We set up some variables containing the details of the Helm chart (chartName, chartVersion, chartValues). These will need to be adjusted to match the Helm chart you're deploying and any specific configurations you need.
We instantiate a Chart object from kubernetes.helm.v3.Chart. This tells Pulumi to deploy the specified Helm chart as part of our Pulumi-managed infrastructure.
We're specifying a Kubernetes provider for Pulumi that uses a given kubeconfig. This kubeconfig should correspond to your OpenShift cluster. You'll need to replace "<your-kubeconfig-content>" with the actual content of your kubeconfig file.
As a last step, we're exporting a variable called resources that will hold the details of all the Kubernetes resources created by the deployment of the Helm chart.

Make sure to replace the placeholders with your actual chart information and cluster configuration.

To run this program, save it in a file named index.ts, and run the following commands:

pulumi up

This command will prompt Pulumi to perform an update, which means it will try to match your cluster's state to the desired state described in the code.

Remember, this script assumes that you've set up your Pulumi account, installed the CLI, and configured it to use your desired account and stack. If you need to select a specific stack or configure your Pulumi environment, please refer to the Pulumi documentation for further instructions.