Deploy the tailscale-subnet-router helm chart on Azure Managed Openshift Service

Question

Pulumi · Accepted Answer

In order to deploy the `tailscale-subnet-router` Helm chart on an Azure Managed OpenShift Service (ARO), you would take the following steps:

1. **Set up an ARO Cluster**: An ARO cluster provides a managed OpenShift cluster that is integrated into Azure infrastructure.
2. **Install Tailscale**: Tailscale must be installed on the cluster for the subnet routes to function correctly.
3. **Configure Helm Deployment**: Use Pulumi's `kubernetes` provider to deploy Helm charts on Kubernetes clusters.

The following is a program written in TypeScript that demonstrates how you would use Pulumi to carry out these steps. This program assumes you already have a Kubernetes cluster running on Azure Red Hat OpenShift.

You will need to have Pulumi installed with appropriate access to your Azure account and the Kubernetes context configured for your ARO cluster.

Here's how you'd do it:

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as kubernetes from "@pulumi/kubernetes";
import * as azureNative from "@pulumi/azure-native";

// Create an instance of the Kubernetes provider pointing to the ARO cluster.
// You must have `kubectl` configured to access your ARO cluster for this to work.
const k8sProvider = new kubernetes.Provider("k8sProvider", {
    kubeconfig: process.env.KUBECONFIG, // Ensure your KUBECONFIG env variable is set
});

// Deploy the Tailscale subnet router Helm chart to the OpenShift cluster using the Kubernetes provider.
const tailscaleSubnetRouterChart = new kubernetes.helm.v3.Chart("tailscale-subnet-router", {
    // A Helm chart for deploying the Tailscale Subnet Router should be available in a Helm repository,
    // you might need to add that repository or specify the chart location if it's not already there.
    // This repository must be added with `helm repo add` prior to running Pulumi up, or you may use a direct URL.
    chart: "tailscale-subnet-router",
    version: "1.0.0", // Use the correct Helm chart version
    namespace: "tailscale", // Assuming `tailscale` namespace is where we want to deploy
    // `values` allows you to provide configuration for the Helm chart.
    values: {
        // Put here the values that are necessary to configure your tailscale subnet router Helm chart
    },
}, { provider: k8sProvider });

// Export the required information after the deployment
export const tailscaleSubnetRouterStatus = tailscaleSubnetRouterChart.status;

```

**Understanding the Program:**
- Azure Pulumi SDK (`@pulumi/azure-native`) is imported, but in this example, we do not create an ARO cluster, as we assume the cluster is already available.
- The Kubernetes Pulumi SDK (`@pulumi/kubernetes`) is used to deploy applications on Kubernetes. Here, we use the `Chart` class to deploy a Helm chart.
- We instantiate a Kubernetes provider by providing a `kubeconfig` which Pulumi will use to interact with your Kubernetes cluster.
- We deploy a Helm chart that represents the Tailscale Subnet Router on the Kubernetes cluster managed by OpenShift. The `repo` and `version` should match the Helm chart's repository and version details.
- Depending on the Helm chart, the `values` field might require specific Tailscale configurations like API keys or network details.

**Next Steps:**

1. If the `tailscale-subnet-router` chart requires a repository to be added to Helm, you will have to do this step before running `pulumi up`.
2. Once this Pulumi program is set up, run `pulumi up` to execute the deployment.
3. The KUBECONFIG environment variable must be set, and `kubectl` must be configured correctly to communicate with the ARO cluster for the Kubernetes provider to function.

To execute the deployment, you will run `pulumi up` within your Pulumi project directory. This command will initiate the provisioning process based on the above code.

Before running this Pulumi program, ensure that the Tailscale Subnet Router Chart is available in a Helm repository or accessible by a URL, and that you have the required configuration details for the `values` field in the chart.