Deploy the pubsub-emulator helm chart on Digital Ocean Kubernetes Service

Question

Pulumi · Accepted Answer

To deploy the `pubsub-emulator` Helm chart on DigitalOcean's Managed Kubernetes Service (DOKS), you'll follow these steps:

1. Set up a new DigitalOcean Kubernetes cluster using Pulumi's `digitalocean.KubernetesCluster` resource.
2. Deploy the `pubsub-emulator` Helm chart to the cluster using the `kubernetes.helm.v3.Chart` resource.

Let's start by defining our DigitalOcean Kubernetes cluster. We'll utilize the `digitalocean` package in Pulumi to create a DOKS cluster. The cluster will consist of a single node pool with the smallest possible size for demonstration purposes.

After the cluster is provisioned, we install the `pubsub-emulator` using the Pulumi Kubernetes provider by specifying the `kubernetes.helm.v3.Chart` resource. Helm is a package manager for Kubernetes that allows you to define, install, and upgrade Kubernetes applications. The `Chart` is a Helm package that contains all the resource definitions necessary to run an application, tool, or service inside of a Kubernetes cluster. By utilizing a Helm chart, it becomes simple to deploy services like `pubsub-emulator`.

Here is the detailed TypeScript program that accomplishes these tasks:

```typescript
import * as pulumi from '@pulumi/pulumi';
import * as digitalocean from '@pulumi/digitalocean';
import * as k8s from '@pulumi/kubernetes';

// Define the DigitalOcean Kubernetes cluster
const cluster = new digitalocean.KubernetesCluster('do-cluster', {
    // Define the region where our cluster will be created.
    region: digitalocean.Regions.NYC1,
    // Version of Kubernetes to use for the cluster
    version: 'latest',
    // Creating a single node pool with the smallest machine type for cost efficiency
    nodePool: {
        name: 'default-pool',
        size: digitalocean.DropletSlugs.DropletS1VCPU2GB,
        nodeCount: 1, // Single node is sufficient for the pubsub-emulator
    },
});

// Now we need to setup the Kubernetes provider to interact with the DigitalOcean cluster
// The kubeconfig is obtained from the DigitalOcean Kubernetes cluster
// to authenticate and communicate with the cluster.
const k8sProvider = new k8s.Provider('do-k8s', {
    kubeconfig: cluster.kubeConfigs[0].rawConfig,
});

// Deploy pubsub-emulator using the Helm chart
const pubsubEmulatorChart = new k8s.helm.v3.Chart('pubsub-emulator', {
    chart: 'pubsub-emulator',
    fetchOpts: {
        repo: 'https://googlecloudplatform.github.io/pubsub-emulator', // Replace with the correct Helm chart repository
    },
}, { provider: k8sProvider });

// Export the cluster's name and kubeconfig
export const clusterName = cluster.name;
export const kubeconfig = cluster.kubeConfigs[0].rawConfig;

```

Here's what each section of the code does:

- We import the necessary Pulumi packages for DigitalOcean and Kubernetes.
- We create a new DOKS cluster with a single node in the `nyc1` region using the `digitalocean.KubernetesCluster` class. We specify the machine size and the number of nodes.
- We then create a Pulumi Kubernetes provider using the `k8s.Provider` class. This provider uses the kubeconfig from our newly created cluster to authenticate against the Kubernetes cluster.
- We deploy the `pubsub-emulator` Helm chart to DOKS using the `k8s.helm.v3.Chart`. The `repo` option specifies the Helm repository where the chart is located.
- Finally, we export the `clusterName` and `kubeconfig`, which we could use to interact with our Kubernetes cluster from our terminal or CI/CD system.

Keep in mind that the process of setting up the cluster and deploying the application can take several minutes. Once the deployment is finished, you can check the status of the installed Helm release with `kubectl` using the exported kubeconfig.

Please note that the Helm chart repository provided in the `fetchOpts` is just a placeholder. You would need to provide the actual URL of the repository where the `pubsub-emulator` chart is hosted. If `pubsub-emulator` is not available as a Helm chart, you would need to create your Helm chart or use an existing Docker image and define Kubernetes resources manually.

Remember to install the Pulumi CLI and configure your DigitalOcean token by running `pulumi config set digitalocean:token <YOUR_DO_TOKEN>` in your terminal before running this program.