Deploy the datahub helm chart on Digital Ocean Kubernetes Service

To deploy the Datahub Helm chart on the DigitalOcean Kubernetes Service using Pulumi, we will follow these steps:

1. Create a DigitalOcean Kubernetes Cluster: We will use the digitalocean.KubernetesCluster resource to provision a Kubernetes cluster on DigitalOcean. We need to specify the region, version, name, and node pool configuration.

2. Install the Helm chart for Datahub: Once the cluster is up and running, we will use the kubernetes.helm.v3.Chart resource to deploy the Datahub Helm chart onto our DigitalOcean Kubernetes cluster.

3. Configuring Pulumi to Use DigitalOcean and Kubernetes: Ensure you've set up the Pulumi DigitalOcean provider by exporting DIGITALOCEAN_TOKEN environment variable with your DigitalOcean personal access token and Pulumi Kubernetes provider configured with kubeconfig.

Here is the TypeScript program that creates a DigitalOcean Kubernetes cluster and deploys the Datahub Helm chart:

import * as pulumi from "@pulumi/pulumi";
import * as digitalocean from "@pulumi/digitalocean";
import * as k8s from "@pulumi/kubernetes";

// Step 1: Create a DigitalOcean Kubernetes Cluster
const cluster = new digitalocean.KubernetesCluster("do-cluster", {
    region: "nyc1",
    version: "latest",  // Use the `doctl kubernetes options versions` command to get a list of valid versions
    nodePool: {
        size: "s-2vcpu-2gb",  // This size is typically sufficient for a test, but you should adjust this based on needs
        name: "default-pool", // Name of the node pool
        nodeCount: 2,         // Number of nodes
    },
});

// Step 2: Deploy the Datahub Helm chart on the DigitalOcean Kubernetes cluster
const datahubChart = new k8s.helm.v3.Chart("datahub", {
    chart: "datahub",
    version: "0.2.0", // Specify the chart version you want to deploy; check the Helm registry for current versions
    fetchOpts: {
        repo: "https://helm.datahubproject.io/", // The repository URL where the chart is located
    },
}, { provider: new k8s.Provider("k8s-provider", {kubeconfig: cluster.kubeConfigs[0].rawConfig})});

// Export the kubeconfig and the cluster endpoint to access the cluster
export const kubeConfig = cluster.kubeConfigs[0].rawConfig;
export const clusterEndpoint = cluster.endpoint;

// Remember to replace "latest" and "0.2.0" with specific versions you wish to deploy

Here's a rundown of the key parts of the code:

• digitalocean.KubernetesCluster: This resource is used to provision a DigitalOcean Kubernetes (DOKS) cluster. When you initiate the deployment process, Pulumi sends a request to DigitalOcean to create a cluster with the specifications provided.

• k8s.helm.v3.Chart: This resource is used to deploy a Helm chart, here specified as datahub. Helm charts are packages that contain pre-configured Kubernetes resources. Helm makes it easier to manage Kubernetes applications, and the Datahub Helm chart includes all the Kubernetes resources necessary to run Datahub on a cluster.

• k8s.Provider: This initializes a new Kubernetes provider instance using the kubeconfig generated by our DigitalOcean Kubernetes cluster. This instructs Pulumi to use this configuration for deploying resources. This is necessary when working with cloud-managed Kubernetes services.

• kubeConfigs[0].rawConfig: The raw kubeconfig file for the cluster which is how you will connect to your cluster with kubectl or other Kubernetes management tools.

• cluster.endpoint: This is the endpoint you will use to access the Kubernetes API server clustered in DigitalOcean.

After running this program with Pulumi (pulumi up), you will have a DigitalOcean Kubernetes cluster running the Datahub application. You can manage the cluster and application lifecycle using Pulumi, such as updating configurations, scaling, and cleanup.

Please note that you need to have Pulumi CLI installed and configured on your machine to run this code. Make sure your Pulumi stack is using the DigitalOcean provider by having a Pulumi.<stack-name>.yaml file with correct configuration in your project directory.