Deploy the kube-dns helm chart on Digital Ocean Kubernetes Service

Question

Pulumi · Accepted Answer

To deploy the kube-dns Helm chart on DigitalOcean Kubernetes Service (DOKS), we will take the following steps using Pulumi and TypeScript:

1. Set up a new Kubernetes cluster on DigitalOcean.
2. Use the Pulumi Kubernetes provider to deploy the kube-dns Helm chart on the newly created cluster.

We will use the `digitalocean.KubernetesCluster` resource to provision a new DOKS cluster and `kubernetes.helm.v3.Chart` to deploy the kube-dns Helm chart. Below is a Pulumi program in TypeScript that demonstrates how to do this.

First, we will start by importing the necessary packages:

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

Then, we will create a new DigitalOcean Kubernetes cluster:

```typescript
const cluster = new digitalocean.KubernetesCluster("my-doks-cluster", {
    region: digitalocean.Regions.NYC3, // Replace with the appropriate region for you
    version: "1.21.5-do.0", // Use the version you require
    nodePool: {
        name: "default",
        size: "s-2vcpu-2gb", // Choose the appropriate size for your workload
        nodeCount: 2, // Number of nodes you want in your DOKS cluster
    },
});
```

Once the cluster is provisioned, we will create a Kubernetes provider instance which enables us to interact with the cluster:

```typescript
const k8sProvider = new k8s.Provider("k8s-provider", {
    kubeconfig: cluster.kubeConfigs[0].rawConfig,
});
```

Finally, we will deploy the kube-dns Helm chart using the Pulumi Kubernetes provider:

```typescript
const kubeDnsChart = new k8s.helm.v3.Chart("kube-dns", {
    chart: "kube-dns",
    version: "1.14.13", // Specify the version of kube-dns you want to deploy
    fetchOpts: {
        repo: "https://charts.helm.sh/stable", // Ensure that this is the correct repository for kube-dns
    },
}, { provider: k8sProvider });
```

We complete the program with the following lines to export the kubeconfig and the Kubernetes cluster name:

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

Below is the complete Pulumi TypeScript program:

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

// Create a new DigitalOcean Kubernetes cluster
const cluster = new digitalocean.KubernetesCluster("my-doks-cluster", {
    region: digitalocean.Regions.NYC3,
    version: "1.21.5-do.0",
    nodePool: {
        name: "default",
        size: "s-2vcpu-2gb",
        nodeCount: 2,
    },
});

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

// Deploy the kube-dns Helm chart
const kubeDnsChart = new k8s.helm.v3.Chart("kube-dns", {
    chart: "kube-dns",
    version: "1.14.13",
    fetchOpts: {
        repo: "https://charts.helm.sh/stable",
    },
}, { provider: k8sProvider });

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

### Explanation

In the above program:

- We create a DigitalOcean Kubernetes cluster with a specified region, version, and node pool size.
- We then instantiate a Pulumi Kubernetes provider pointing to the kubeconfig of our newly created DigitalOcean cluster.
- We deploy the kube-dns Helm chart using the `Chart` resource from the Pulumi Kubernetes provider, specifying the chart name, version, and Helm repository to fetch from.
- Finally, we export the kubeConfig and clusterName which can be used to interact with the cluster outside of Pulumi, for instance, using `kubectl`.

You can run this program using the Pulumi CLI by typing `pulumi up` in your terminal within the directory containing this program. Ensure you have Pulumi installed and configured with your DigitalOcean token. The CLI will prompt you to review changes and confirm the deployment, after which your DOKS cluster and kube-dns will be deployed.

Please ensure the Helm chart name and version are correct and available in the Helm repository specified. The DigitalOcean Kubernetes version specified should also be available in the region you're deploying to. Adjust these values based on your requirements.

For more detailed information on each of these components and their configurations, please visit the documentation:

- [`digitalocean.KubernetesCluster`](https://www.pulumi.com/registry/packages/digitalocean/api-docs/kubernetescluster/)
- [`kubernetes.helm.v3.Chart`](https://www.pulumi.com/registry/packages/kubernetes/api-docs/helm/v3/chart/)

Remember to destroy the resources with `pulumi destroy` if they are no longer needed, to avoid incurring unnecessary charges.