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

Question

Pulumi · Accepted Answer

To deploy the `nats-server` Helm chart on DigitalOcean Kubernetes Service using Pulumi, you'll need to follow these main steps:

1. **Set up a DigitalOcean Kubernetes cluster**: You need a running Kubernetes cluster on DigitalOcean to deploy your Helm chart. You'll use the `digitalocean.KubernetesCluster` resource to create and configure your cluster.
   
2. **Install the Helm Chart**: Once you have a cluster, you use Pulumi's `kubernetes.helm.v3.Chart` resource to deploy the `nats-server` Helm chart onto your DigitalOcean Kubernetes cluster.

Below you will find a detailed Pulumi script that performs these two steps. This script will be written in TypeScript due to its strong typing system, which aids in catching errors early in the development process.

Here's a Pulumi program that will achieve your goal:

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

// Step 1: Create a Kubernetes cluster in DigitalOcean
const cluster = new digitalocean.KubernetesCluster('do-cluster', {
  region: 'nyc1', // Specify the DigitalOcean region. Change this to the region you prefer.
  version: '1.20.2-do.3', // Specify the Kubernetes version, Note: use a valid version for the region.
  nodePool: {
    name: 'default',
    size: 's-1vcpu-2gb', // Node size (e.g., 's-1vcpu-2gb' for the smallest node in the NYC1 region)
    nodeCount: 2, // Number of nodes in the node pool
  },
});

// Step 2: Deploy the nats-server Helm chart to the created Kubernetes cluster
const natsServerChart = new kubernetes.helm.v3.Chart('nats-server', {
  chart: 'nats',
  version: '0.9.0', // Use the version of the Helm chart you wish to deploy
  fetchOpts: {
    repo: 'https://nats-io.github.io/kube-nats', // The Helm repo URL where the chart is hosted
  },
}, { provider: new kubernetes.Provider('k8s-provider', { kubeconfig: cluster.kubeConfigs[0].rawConfig }) });

// Export the cluster's kubeconfig and the nats-server Helm chart status
export const kubeconfig = cluster.kubeConfigs[0].rawConfig;
export const natsStatus = natsServerChart.status;

```

Here's what each section does:

- **Create a Kubernetes cluster**: This section uses DigitalOcean's Kubernetes service to create a cluster with the desired version and in the specified region. It defines a node pool, which is a group of droplets (VMs) that will run your Kubernetes workloads.

- **Deploy Helm chart**: This section installs a Helm chart named `nats-server`. It specifies the chart's name and the repository where the chart can be found. The `provider` parameter is used to tell Pulumi to use the kubeconfig from the created DigitalOcean Kubernetes cluster to deploy the chart.

- **Export outputs**: The script exports the kubeconfig for the created cluster, which you can use to manage your Kubernetes cluster with `kubectl`, and the status of the deployed `nats-server` Helm chart.

Make sure you have Pulumi and the DigitalOcean Pulumi provider configured locally. You also need to have access to your DigitalOcean token and have it set up with Pulumi.

After initializing a new Pulumi project, you can save this script as `index.ts` and run it with Pulumi commands to create the infrastructure and deploy the Helm chart:

```bash
pulumi up
```

After the deployment, use the kubeconfig to interact with your Kubernetes cluster and manage the NATS server:

```bash
pulumi stack output kubeconfig --show-secrets > kubeconfig.yaml
kubectl --kubeconfig kubeconfig.yaml get pods
```

Note that in the script, you might need to change the region, node size, node count, and Helm chart version depending on your needs and the current availability within DigitalOcean and the nats-server Helm chart versioning.