Deploy the k8s-spot-rescheduler helm chart on Digital Ocean Kubernetes Service

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Pulumi · Accepted Answer

To deploy the `k8s-spot-rescheduler` Helm chart on Digital Ocean Kubernetes Service (DOKS), you'll need to create a Kubernetes cluster on Digital Ocean and then use the Helm Chart resource in Pulumi to deploy the rescheduler. Here's a step-by-step guide on how to achieve this.

First, you will create a Kubernetes cluster on Digital Ocean using the `digitalocean.KubernetesCluster` resource. This resource allows you to provision a managed Kubernetes cluster on the Digital Ocean cloud platform. The properties required to create a cluster include the name of the cluster, region, version, and the node pool configuration which dictates the size and number of nodes (droplets) in your cluster.

Next, we will use the `kubernetes.helm.v3.Chart` resource from Pulumi's Kubernetes provider to deploy the `k8s-spot-rescheduler` Helm chart. This resource is a representation of a Helm chart in Pulumi and is used to deploy packaged applications to Kubernetes clusters. You'll need to specify the chart name, which indicates the Helm chart to be deployed, and the chart values, which are configuration parameters for your Helm chart.

Here's a complete Pulumi TypeScript program that performs these tasks:

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

// Create a Kubernetes cluster on Digital Ocean.
const cluster = new digitalocean.KubernetesCluster("do-cluster", {
    region: "nyc3",
    version: "latest",
    nodePool: {
        size: "s-2vcpu-2gb",
        name: "default",
        nodeCount: 3, // This is the number of nodes for the cluster
    },
});

// Once the cluster is provisioned, we configure Pulumi to use the cluster credentials.
const kubeconfig = cluster.kubeConfigs[0].rawConfig;

// A Kubernets provider to use the above kubeconfig for deploying Helm charts to DOKS.
const k8sProvider = new k8s.Provider("do-k8s", {
    kubeconfig
});

// Deploy the k8s-spot-rescheduler Helm chart on the Digital Ocean Kubernetes cluster.
const chart = new k8s.helm.v3.Chart("k8s-spot-rescheduler", {
    chart: "k8s-spot-rescheduler",
    version: "YOUR_DESIRED_CHART_VERSION", // Specify the chart version
    fetchOpts: {
        repo: "https://charts.example.com/", // Replace with the actual Helm chart repository URL
    },
}, { provider: k8sProvider });

// Export the cluster's kubeconfig and the spot rescheduler service endpoint.
export const kubeConfigOutput = kubeconfig;
export const spotReschedulerService = chart.getResource("v1/Service", "k8s-spot-rescheduler/k8s-spot-rescheduler-service");

```

As you can see, the `kubeConfigOutput` variable is exported from the Pulumi program. This output can be used to interact with your Kubernetes cluster using `kubectl` or any Kubernetes-compatible tooling. The `spotReschedulerService` export can be used to find the details of the service endpoint created by the Helm chart, such as the IP address or the DNS name.

Please replace `"YOUR_DESIRED_CHART_VERSION"` with the version number of the `k8s-spot-rescheduler` Helm chart that you want to install and `"https://charts.example.com/"` with the URL of the Helm repository where the chart is located. If the chart is part of the default repositories that come configured with Helm, you may omit the `repo` attribute of `fetchOpts`.

Remember that operations on cloud providers might incur costs, and it’s a good idea to review the pricing for Digital Ocean Kubernetes services.

Make sure that you have the correct Digital Ocean access token configured in your environment so that Pulumi can manage resources on your behalf. You can review Digital Ocean and Pulumi documentation for details on obtaining and configuring access tokens.

Once you've set up Pulumi and have the appropriate access tokens, you can run the above program with the Pulumi CLI by executing `pulumi up` in the directory where this program is saved, which will start provisioning the resources as defined by the program. The CLI will present you with a summary of the planned changes before performing them, and you can confirm to proceed. After the deployment is complete, you can use the exported kubeconfig to manage your Kubernetes cluster.