Deploy the nginx-charts helm chart on Opensshift

Question

Pulumi · Accepted Answer

To deploy the nginx Helm chart on an OpenShift cluster using Pulumi, you'll need to use the Kubernetes provider, which allows you to interact with your Kubernetes cluster in a declarative manner. The main resource we'll use is `kubernetes.helm.v3.Chart`, which represents a Helm chart resource to be applied to your cluster.

The provided TypeScript program assumes that you've already set up your OpenShift cluster and configured `kubectl` to interact with it. The program also presumes you have Pulumi installed and set up to manage your Kubernetes resources.

First, I'll explain the general structure of the deployment process:

1. **Initialization**: Configure the Pulumi project with the necessary imports and initialize the Kubernetes provider to interact with your OpenShift cluster.
2. **Helm Chart Deployment**: Use the `Chart` resource from Pulumi's Kubernetes provider to deploy the nginx chart. We will set some basic values, but depending on your requirements, this can be expanded.
3. **Exporting Outputs**: Optionally, if the Helm chart generates any output (like service URLs or ingress endpoints), you might want to export these values to view them easily after deployment.

Here's the program that deploys the nginx chart to your OpenShift cluster:

```typescript
import * as kubernetes from '@pulumi/kubernetes';

// Create a Kubernetes provider instance that uses the current context from your kubeconfig file.
// This context should already be configured to communicate with your OpenShift cluster.
const k8sProvider = new kubernetes.Provider('k8s', {
    kubeconfig: kubernetes.config.getConfig().kubeconfig,
});

// Deploy nginx using the Helm Chart.
// The `Chart` resource uses the Helm package manager to deploy applications defined by a Helm Chart.
const nginxChart = new kubernetes.helm.v3.Chart('nginx', {
    // `repo` specifies the Helm chart repository to use.
    // `chart` specifies the name of the chart in the repository.
    repo: 'bitnami', // This is the repository where the nginx Helm chart is stored.
    chart: 'nginx', // This is the name of the chart you want to deploy.
    // Modify `values` to set any chart values you need.
    // For instance, you might want to set the number of replicas, expose additional ports or configure a persistent volume.
    values: {
        // Example of setting chart values:
        // replicaCount: 3,
        // service: {
        //     type: 'LoadBalancer',
        // },
    },
}, { provider: k8sProvider });

// Export the service's cluster IP to easily access the nginx service.
export const nginxServiceClusterIp = nginxChart.getResourceProperty('v1/Service', 'nginx', 'spec').apply(spec => spec.clusterIP);
```

The above program will request Pulumi to deploy the nginx Helm chart from the Bitnami repository on your OpenShift cluster.

Here’s a quick rundown of what each part of the code does:

- The `kubernetes.Provider` object represents the Kubernetes provider which Pulumi will use to communicate with a specific cluster. It uses your existing kubeconfig file, which must be configured beforehand to use the OpenShift context.

- The `kubernetes.helm.v3.Chart` is the Pulumi resource that represents Helm's chart deployment. It takes various arguments like the `repo`, the `chart` name, and `values` for any configurations within the chart. By setting the `provider` option, we ensure that this Helm chart is deployed using the provider instance we configured earlier, effectively targeting your OpenShift cluster.

- The `export` statement is used to expose the cluster IP of the nginx service created by the Helm chart deployment. You can use this IP to access the nginx service within your cluster or further configure ingress rules or a load balancer to make it accessible from outside the cluster, depending on your OpenShift configuration.

Make sure to run `pulumi up` to review and deploy the infrastructure changes after you've written the program. Pulumi CLI will show you a preview of the resources that will be created and ask for confirmation before proceeding with the deployment.