Deploy the kube-dns helm chart on AWS EKS

Question

Pulumi · Accepted Answer

To deploy the `kube-dns` helm chart on AWS EKS using Pulumi, you will need to perform several steps:

1. Set up an EKS cluster if you don't already have one. We will use the `eks.Cluster` resource from the Pulumi EKS package which provides a high-level abstraction to simplify creating EKS clusters.

2. Once we have an EKS cluster, we'll use the `kubernetes.helm.sh/v3.Chart` resource to deploy `kube-dns` from the Helm chart repository. Note that `kube-dns` is typically deployed by default as part of Kubernetes' cluster add-ons, so you might not need to deploy it manually if your EKS cluster already includes it.

Here is a detailed program in TypeScript that performs these steps:

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

// Step 1: Create an AWS EKS Cluster.
// We use the eks.Cluster resource which conveniently sets up an EKS cluster
// This includes the EKS control plane, worker nodes, and associated infrastructure like VPCs and security groups.
const cluster = new eks.Cluster("my-cluster", {
  // Define the desired number of cluster nodes; you can specify more options if needed.
  desiredCapacity: 2,
  minSize: 1,
  maxSize: 3,
  // Define the instances type for the worker nodes.
  instanceType: "t2.medium",
  // Optionally define the Kubernetes version (defaults to the latest version supported by EKS if not specified).
  version: "1.21",
});

// Step 2: Deploy kube-dns using the Helm chart.
// We use the k8s.helm.v3.Chart resource to deploy kube-dns.
// Note that the Helm chart repository URL and the chart name must be known.
// For example purposes, we're assuming kube-dns is the name of the chart in the stable repository.
const kubeDnsChart = new k8s.helm.v3.Chart("kube-dns", {
  chart: "kube-dns",
  // Specify the repository URL; the URL here is hypothetical as it'll be different for the real helm chart.
  // Often, you can find this URL in the official documentation or on artifact hubs like Artifact Hub.
  repo: "https://helm-repo-url.com/",
  namespace: "kube-system", // Normally, DNS-related services run in the kube-system namespace.
  // Values for the Chart can be provided according to your needs.
  values: {
    // Tune these values according to the 'kube-dns' chart's values.yaml.
  },
}, { provider: cluster.provider });

// Export the cluster's kubeconfig.
export const kubeconfig = cluster.kubeconfig;
```

### Explanation

- **eks.Cluster**: This will set up a Kubernetes cluster on AWS EKS. We specify the instance type, desired capacity (the number of worker nodes), min and max size (for scaling purposes), and optionally the Kubernetes version. You can also specify other configurations such as tags, VPC settings, advanced options for node groups, etc.

- **k8s.helm.v3.Chart**: This is responsible for fetching the `kube-dns` Helm chart from the specified repository and deploying it to your EKS cluster. You would need to specify the namespace (typically `kube-system` for DNS services), chart name, and repository URL among other settings.

- **kubeconfig**: This exports the kubeconfig of the provisioned EKS cluster which enables you to connect to your Kubernetes cluster using kubectl or any other Kubernetes management tool.

Make sure to replace `https://helm-repo-url.com/` with the actual URL of the Helm repository containing the `kube-dns` chart. Check the default repositories in your Helm setup or the documentation around `kube-dns` to find the correct URL and chart name.

Important: Before running this Pulumi program, ensure that you have the Pulumi CLI and AWS CLI installed and configured with appropriate access rights for creating EKS clusters and deploying services. Running this program will perform real operations on AWS which may incur charges.