Deploy the nats-streaming helm chart on Digital Ocean Kubernetes Service

Question

Pulumi · Accepted Answer

To deploy the NATS Streaming Helm chart on Digital Ocean Kubernetes Service using Pulumi, you will primarily need to set up the following:

1. A Digital Ocean Kubernetes (DOKS) cluster where the NATS Streaming service will run.
2. The Helm chart for NATS Streaming, which will be deployed to the DOKS cluster.

Pulumi's `@pulumi/digitalocean` package provides a `KubernetesCluster` resource that you can use to create a DOKS cluster. Once you have the cluster set up, you can use Pulumi's `@pulumi/kubernetes` package to deploy the NATS Streaming Helm chart to that cluster.

Here's a detailed program written in TypeScript that accomplishes deploying the NATS Streaming Helm chart on Digital Ocean Kubernetes Service:

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

// First, create a Digital Ocean Kubernetes cluster where your application will be deployed.
const cluster = new digitalocean.KubernetesCluster('do-cluster', {
  region: digitalocean.Regions.NYC1, // Select your desired region
  version: '1.20.2-do.0',           // Specify the DOKS cluster version
  nodePool: {
    name: 'default',
    size: digitalocean.DropletSlugs.DropletS2VCPU2GB,  // Choose the droplet size
    nodeCount: 2,                                      // Specify the number of nodes
  },
});

// Once the cluster is deployed, we can configure Pulumi to use the cluster's kubeconfig.
const provider = new kubernetes.Provider('do-k8s', {
  kubeconfig: cluster.kubeConfigs[0].rawConfig,
});

// Now that we have a provider that knows how to communicate with our Digital Ocean Kubernetes cluster,
// we can deploy the NATS Streaming Helm chart to the cluster.

// The Helm chart for NATS Streaming is available in the default Helm repository, so we just need to specify its name and version.
const natsChart = new kubernetes.helm.v3.Chart('nats-streaming', {
  chart: 'nats-streaming',
  version: '0.8.0',         // Specify the Helm chart version you want to deploy
  fetchOpts: {
    repo: 'https://helm.sh/charts',  // NATS Streaming Helm chart repository
  },
}, { provider });

// Export the cluster's kubeconfig and the NATS service endpoint.
export const kubeconfig = cluster.kubeConfigs[0].rawConfig;
export const natsEndpoint = natsChart.getResource('v1/Service', 'default/nats-streaming').status.apply(status => status.loadBalancer.ingress[0].ip);

```

### Explanation

In the above TypeScript program for Pulumi:

1. We first import the necessary packages from Pulumi's Digital Ocean and Kubernetes libraries.

2. We create a new Digital Ocean Kubernetes cluster by instantiating `digitalocean.KubernetesCluster`. Here:
   - `region` specifies the geographic location for the cluster.
   - `version` sets the version of Kubernetes to use.
   - `nodePool` defines the details of the node pool, such as name, droplet size, and node count.

3. After the cluster is created, we set up a Pulumi Kubernetes provider by creating a new instance of `kubernetes.Provider`. The provider configuration includes the kubeconfig of the created cluster, which allows Pulumi to communicate with the cluster.

4. Subsequently, we deploy the NATS Streaming Helm chart using Pulumi's Helm Chart resource. We specify the chart name (`nats-streaming`), version, and repository.

5. Finally, we use Pulumi's exports to output the kubeconfig for the created cluster and the NATS service endpoint. The `kubeconfig` is used to access the Kubernetes cluster, while `natsEndpoint` provides the IP address to reach the NATS Streaming service.

When you run this program with Pulumi, it will handle provisioning the DOKS cluster and deploying the NATS Streaming Helm chart to that cluster. You can then use the exported `natsEndpoint` to interact with your NATS Streaming service.