Deploy the hadoop-yarn helm chart on Digital Ocean Kubernetes Service

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Pulumi · Accepted Answer

To deploy the Hadoop-YARN Helm chart on Digital Ocean Kubernetes Service using Pulumi, we will perform the following steps:

1. **Create a Digital Ocean Kubernetes Cluster**: This involves setting up a Kubernetes cluster on Digital Ocean where we can deploy our applications.
2. **Deploy the Hadoop-YARN Helm Chart**: Once we have our Kubernetes cluster in place, we will then deploy the Hadoop-YARN chart onto our cluster.

We use the `digitalocean.KubernetesCluster` resource to create a Kubernetes cluster on Digital Ocean. Adjust the properties of the cluster like `region`, `version`, and `nodePool` according to your requirements or use the defaults provided in the example.

For deploying the Hadoop-YARN Helm chart, we'll utilize the `kubernetes.helm.v3.Chart` resource from the Kubernetes provider to instruct Pulumi to install a Helm chart into our newly created cluster.

You will need to have Pulumi set up as well as `kubectl` configured to interact with your DigitalOcean Kubernetes cluster. Ensure that you have added your DigitalOcean Access Token as described in the Pulumi documentation so that Pulumi can authenticate and manage resources on your behalf.

Here is the Pulumi program written in TypeScript that achieves this:

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

// Create a Digital Ocean Kubernetes cluster where we will deploy our Helm chart.
const cluster = new digitalocean.KubernetesCluster("do-cluster", {
    region: "nyc1", // The region for the cluster, choose the one closest to you or your users.
    version: "latest", // Use the latest version of Kubernetes.
    nodePool: {
        name: "default-pool",
        size: "s-2vcpu-2gb", // The size of the Droplets that will become worker nodes.
        nodeCount: 2, // The number of worker nodes in your cluster.
    },
});

// Instantiate the Kubernetes provider to interact with the Digital Ocean Kubernetes cluster.
const k8sProvider = new k8s.Provider("do-k8s", {
    kubeconfig: cluster.kubeConfigs[0].rawConfig,
});

// Deploy the Hadoop-YARN Helm chart into the Kubernetes cluster.
const hadoopChart = new k8s.helm.v3.Chart("hadoop-yarn", {
    chart: "hadoop", // The name of the chart, which should be "hadoop" if you're using the stable repo.
    version: "3.0.0", // Specify the version of the Helm chart. Check chart repository for latest version.
    fetchOpts: {
        repo: "https://charts.bitnami.com/bitnami", // This is the Bitnami repository which hosts the Hadoop chart.
    },
}, { provider: k8sProvider });

// Export the Cluster's kubeconfig and the Hadoop chart's status.
export const kubeconfig = cluster.kubeConfigs[0].rawConfig;
export const hadoopStatus = hadoopChart.status;
```

In this program:

- We start by importing the necessary Pulumi libraries for both DigitalOcean and Kubernetes.
- We create an instance of the Digital Ocean Kubernetes cluster. 
- We set up the Kubernetes provider to interact with the cluster using the generated kubeconfig from the cluster we created.
- We deploy the Hadoop-YARN Helm chart by specifying the chart's name and version, and providing the URL of the Helm repository that contains the chart. 
- We then export the kubeconfig to enable `kubectl` to interact with the Digital Ocean Kubernetes cluster and the status of the Hadoop deployment to provide visibility into the deployment state.

After writing this program to a file (e.g., `index.ts`), you would run it using Pulumi CLI commands `pulumi up` to provision the resources defined in your program.

Please ensure that you have selected the appropriate chart version and repository during the deployment process. The provided version and repository in the example are subject to change and should be verified from the official Helm chart repositories.