Deploy the redis-setup helm chart on Digital Ocean Kubernetes Service

Question

Pulumi · Accepted Answer

To deploy the `redis-setup` Helm chart on a DigitalOcean Kubernetes Service (DOKS) cluster using Pulumi, we'd have to follow these steps:

1. **Provision a Kubernetes Cluster on DigitalOcean**: We first need to spin up a new Kubernetes cluster on DigitalOcean using Pulumi's DigitalOcean provider.
2. **Install Helm Chart for Redis**: After the Kubernetes cluster is available, we utilize Pulumi's Kubernetes provider to deploy the `redis-setup` Helm chart to our newly created cluster.

In this context, Helm Charts are packages for Kubernetes resources. They manage Kubernetes applications and define, install, and upgrade even the most complex Kubernetes applications.

Below is a comprehensive TypeScript program that uses Pulumi to perform these tasks.

Please note that to run this code, you should have Pulumi installed and configured for use with the DigitalOcean token, and the Kubernetes configuration should be set appropriately for Pulumi to interact with your cluster.

First, let's start by setting up the cluster:

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

// Create a DigitalOcean Kubernetes cluster.
const cluster = new digitalocean.KubernetesCluster("do-cluster", {
    region: digitalocean.Regions.NYC1,
    version: "latest",
    nodePool: {
        name: "default",
        size: digitalocean.DropletSlugs.DropletS2VCPU2GB,
        nodeCount: 2,
    },
});

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

In the above code:
- We create a DigitalOcean Kubernetes cluster in the NYC1 region using two `s-2vcpu-2gb` droplets for our node pool.
- We export the kubeconfig, which we will later use to interact with the Kubernetes API server of the cluster.

Next, we deploy the `redis-setup` Helm chart:

```typescript
// Start by defining a Kubernetes Provider instance using the exported kubeconfig from our cluster.
const k8sProvider = new k8s.Provider("k8s-provider", {
    kubeconfig: kubeconfig,
});

// Deploy the 'redis-setup' Helm chart on the cluster using `@pulumi/kubernetes` package.
const redisChart = new k8s.helm.v3.Chart("redis-setup", {
    // It is assumed that 'redis-setup' is the name of the chart within the default Helm chart repository.
    // If the chart is in a custom repository or requires additional values, you may need to adjust this definition.
    chart: "redis",
    // Define namespace if you have a specific namespace for your Helm charts.
    // It will default to 'default' if not specified, or use the namespace 'redis-namespace'.
    namespace: "redis-namespace",
    // If the chart requires any custom values, specify them here. For example:
    // values: {
    //   usePassword: false,
    //   replicaCount: 1,
    // },
}, { provider: k8sProvider });

// Export the service endpoint.
export const redisEndpoint = pulumi.all([redisChart.getResource("v1/Service", "redis-setup-master")]).apply(resources => {
    const service = resources[0];
    if (service) {
        // Assuming 'redis-setup-master' is one of the services created by the Helm chart and exposes Redis.
        return service.spec.clusterIP;
    }
});
```

In the above code:
- We create a new instance of Pulumi Kubernetes Provider using the kubeconfig we obtained from the cluster creation step.
- We deploy the `redis-setup` Helm chart to the Kubernetes cluster by instantiating `Chart` from `@pulumi/kubernetes/helm/v3`.
  - If your `redis-setup` Helm chart is in a custom helm repository, you'll need to add that repository to your helm repos via `helm repo add` or specify the `repo` property in the ChartArgs.
- We specify the namespace where to install the chart. If this namespace is not yet created in the cluster, Helm will create it.
- We omit the values property which allows us to override default configuration values for the chart; add this if you need to customize your Redis deployment.
- Finally, we attempt to export `redisEndpoint`, which is supposed to be the cluster IP for accessing the deployed Redis master service. Please note, however, that this is just an example and the exact reference to services and other resources will be specific to the actual Helm chart used.

After writing and saving your Pulumi code, you would run it using the Pulumi CLI:

```
pulumi up
```

This will prompt you to review and confirm the actions Pulumi plans to take, and when you approve, it will provision the resources, outputting the kubeconfig and the Redis service endpoint upon successful completion.

Remember to replace `redis-setup` with the actual chart name and provide additional configuration if required for your scenario.