Deploy the twitter-app helm chart on Digital Ocean Kubernetes Service

Question

Pulumi · Accepted Answer

In order to deploy your `twitter-app` Helm chart on a Digital Ocean Kubernetes cluster using Pulumi, we will go through a series of steps involving two main resources:

1. `digitalocean.KubernetesCluster`: This resource will set up a Kubernetes cluster on Digital Ocean.
2. `kubernetes.helm.sh/v3.Chart`: After having the Kubernetes cluster, we will make use of this resource to deploy the `twitter-app` Helm chart onto the cluster.

Here is the outline of the steps that will be taken in the Pulumi program:
- We will start by creating a new Kubernetes cluster on Digital Ocean with the necessary specifications.
- Once the cluster is provisioned, we will use the Helm chart resource to deploy your `twitter-app`.
- Finally, we will export the Kubernetes cluster's name and endpoint for you to access.

Now, let's write out the program:

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

// Create a new Digital Ocean Kubernetes cluster
const cluster = new digitalocean.KubernetesCluster("twitter-app-cluster", {
    region: "nyc3", // Define the region where the cluster will be created
    version: "1.21.5-do.0", // Define the version of Kubernetes
    nodePool: {
        name: "worker-pool",
        size: "s-2vcpu-2gb", // Define the size of the Droplets
        nodeCount: 2,        // Define the number of Droplet instances
    },
});

// Create a Kubernetes provider instance using the kubeconfig from the previously created cluster
const k8sProvider = new k8s.Provider("do-k8s", {
    kubeconfig: cluster.kubeConfigs[0].rawConfig,
});

// Deploy the twitter-app helm chart using the Pulumi Kubernetes provider
const twitterAppChart = new k8s.helm.sh.v3.Chart("twitter-app", {
    chart: "twitter-app", // This assumes you have a helm chart named 'twitter-app'
    version: "0.1.0",     // Replace with the correct chart version
    fetchOpts:{
        repo: "http://charts.example.com/", // Replace with your Helm chart's repository URL
    },
}, { provider: k8sProvider });

// Export the cluster name and endpoint for accessing your Kubernetes cluster
export const clusterName = cluster.name;
export const kubeClusterEndpoint = cluster.endpoint;
```

In the above program:
- We import the necessary modules from `@pulumi/digitalocean` and `@pulumi/kubernetes`.
- We create a Kubernetes cluster resource with an appropriate name, region, version, and droplet sizes.
- The `kubeconfig` output from this cluster creation is used to define a Pulumi Kubernetes provider.
- Finally, we use this provider to deploy a Helm chart which represents the `twitter-app`.

After deploying your Helm chart, you can access your Kubernetes cluster by using the kubeconfig file, and you can manage your application within it using `kubectl` or similar tools. To use the code, place it in an index.ts file in a Pulumi project, and run `pulumi up` to preview and deploy the changes. Be sure to replace "twitter-app" and its version with the appropriate values for your application, and also replace the helm repo URL with the URL where your chart is hosted.