Deploy the tailscale-subnet-router helm chart on Opensshift

Question

Pulumi · Accepted Answer

To deploy the Tailscale Subnet Router Helm chart on an OpenShift cluster, you first need an existing OpenShift cluster. The following Pulumi program demonstrates how to use the `kubernetes.helm.sh/v3.Chart` resource to deploy a Helm chart to a Kubernetes cluster, which could be an OpenShift cluster in this case.

OpenShift is Kubernetes, and so in most cases, you work with OpenShift and Kubernetes resources interchangeably. However, ensure you have the proper permissions to deploy Helm charts in your OpenShift cluster, as well as the correct Helm chart for Tailscale Subnet Router.

This Pulumi program assumes you already have configured your Pulumi environment with Kubernetes access to your OpenShift cluster, typically through a KubeConfig file.

Below is a detailed Pulumi TypeScript program that does this:

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

// You must have the Helm Chart details for Tailscale Subnet Router,
// usually available in Tailscale's documentation or Helm repository.

// Define the namespace where the Helm chart should be deployed. If it does not exist,
// you can create it using Pulumi as well.
const namespace = "tailscale";

// Create the namespace if it doesn't exist.
const ns = new kubernetes.core.v1.Namespace("tailscale-namespace", {
    metadata: { name: namespace },
});

// Deploy the Tailscale Subnet Router Helm chart.
const tailscaleSubnetRouterChart = new kubernetes.helm.v3.Chart("tailscale-subnet-router", {
    namespace: namespace, // Deploy to the created 'tailscale' namespace
    chart: "tailscale-subnet-router",
    // Assuming the tailscale-subnet-router Helm chart is available in the repository below,
    // otherwise, you need to provide the correct repository URL where the chart can be found.
    fetchOpts: { 
        repo: "https://helm.tailscale.com",
    },
    // Include any values to override in the Helm chart
    // You would consult the Tailscale Helm chart documentation for available options.
    values: {
        // Custom values to override default chart values
    },
}, { dependsOn: ns }); // This makes sure the chart is not deployed before the namespace creation.

export const chartName = tailscaleSubnetRouterChart.metadata.name;
```

This Pulumi program does the following:

1. Imports the `@pulumi/kubernetes` module, which contains helpers for deploying Kubernetes resources.
2. Defines the target namespace for Tailscale Subnet Router deployment.
3. Creates a Kubernetes Namespace object if it doesn't already exist. This specifies where the Tailscale Subnet Router will live within the OpenShift cluster.
4. Uses the `Chart` class from the Kubernetes Helm package to define a Helm chart deployment. You provide it with several parameters such as the chart name, the repository where the chart is located, the namespace where to deploy, and any custom values you wish to override in the default chart.
5. Marks the namespace creation as a dependency for the chart deployment to ensure the namespace is ready before attempting to deploy the chart.
6. Exports the chart name for easy access or for use in a CI/CD system.

Remember to refer to [Pulumi's Kubernetes documentation](https://www.pulumi.com/docs/reference/pkg/kubernetes/helm/v3/chart/) for more information on deploying Helm charts with Pulumi.

Before running `pulumi up`, be sure that `kubectl` is configured to point to your OpenShift cluster. If needed, consult the OpenShift and Tailscale documentation to configure specific Tailscale options and prerequisites.