Deploy the nats-server helm chart on Azure Managed Openshift Service

Question

Pulumi · Accepted Answer

To deploy the NATS server Helm chart on Azure Managed OpenShift Service using Pulumi, we'll follow these steps:

1. Provision an Azure Red Hat OpenShift cluster:
   - We'll use the `azure-native.redhatopenshift.OpenShiftCluster` resource to create a Red Hat OpenShift Cluster in Azure. This will give us a managed Kubernetes environment where we can deploy our applications with OpenShift's additional security, enterprise services integration, and ease of use.

2. Deploy the NATS server Helm chart:
   - We'll use the `kubernetes.helm.v3.Chart` resource from the Kubernetes Pulumi provider to deploy the NATS server Helm chart to our OpenShift cluster.

Here's how you would write the Pulumi program in TypeScript to achieve this:

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as azureNative from "@pulumi/azure-native";
import * as k8s from "@pulumi/kubernetes";

// Create an OpenShift cluster on Azure.
const openshiftCluster = new azureNative.redhatopenshift.OpenShiftCluster("myOpenShiftCluster", {
    // Provide necessary properties like location, resourceGroupName, and clusterProfile details here.
    // Make sure to replace placeholders with actual values as applicable, for example:
    resourceGroupName: "myResourceGroup",
    location: "eastus", // Replace with an actual Azure location
    clusterProfile: {
        // ... Specify domain, version, and other cluster properties
    },
    masterProfile: {
        // ... Define your master node properties
    },
    workerProfiles: [
        // ... Define your worker node properties
    ],
    // For detailed configuration properties refer to the documentation:
    // https://www.pulumi.com/registry/packages/azure-native/api-docs/redhatopenshift/openshiftcluster/
});

// Deploy the NATS server Helm chart using the Kubernetes Provider.
// First, we must create a provider that points to the newly created OpenShift cluster.
const k8sProvider = new k8s.Provider("openshiftK8s", {
    kubeconfig: openshiftCluster.kubeconfig.apply(kubeconfig => kubeconfig.rawData),
});

// Now we can use the k8s provider to deploy the NATS server Helm chart.
const natsChart = new k8s.helm.v3.Chart("natsChart", {
    chart: "nats",
    version: "0.7.x", // Specify the Helm chart version you want to deploy
    fetchOpts: {
        repo: "https://nats-io.github.io/k8s/helm/charts/", // The NATS Helm repository
    },
    // Optional: Specify any custom values for the Helm chart.
    values: {
        // ...
    },
}, { provider: k8sProvider });

// Exports the Kubeconfig and NATS service endpoint
export const kubeconfig = openshiftCluster.kubeconfig.apply(kubeconfig => kubeconfig.rawData);
export const natsServiceEndpoint = pulumi.interpolate`${natsChart.getResourceProperty("v1/Service", "nats", "status").apply(status => status.loadBalancer.ingress[0].hostname)}`;
```

In the above example:

- We create an OpenShift cluster using the `azure-native.redhatopenshift.OpenShiftCluster` resource. This involves specifying properties such as location, resource group, and cluster specifications.
- The `azureNative.redhatopenshift.OpenShiftCluster` class constructor takes in a set of arguments to establish cluster properties. You'll need to replace placeholders with actual values and choose the appropriate configurations for your needs. For more detailed property information, refer to the [Azure OpenShiftCluster documentation](https://www.pulumi.com/registry/packages/azure-native/api-docs/redhatopenshift/openshiftcluster/).

- After the OpenShift cluster has been created, we set up a Kubernetes provider that targets our OpenShift cluster using the output kubeconfig data. This provider is then used to deploy the NATS server Helm chart using the `kubernetes.helm.v3.Chart` class, where we need to specify the Helm chart and version.

- The `fetchOpts` property is configured with the NATS Helm repository from which to fetch the NATS Helm chart.

- We also show how to optionally pass a set of custom values to the Helm chart through the `values` property. Although optional, this can be used to override default settings within the Helm chart.

- Finally, at the end of the program, we use Pulumi's export feature to output the kubeconfig file and the NATS server endpoint when the deployment is completed. This allows you to connect to your OpenShift cluster and access the NATS server from your local machine.

Remember that when running this Pulumi program, you'll need to have the Pulumi CLI installed, along with the necessary cloud provider credentials (in this case Azure) set up so that Pulumi can provision resources on your behalf.