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

Question

Pulumi · Accepted Answer

To deploy the `flask-app` Helm chart on the Digital Ocean Kubernetes Service using Pulumi, we will follow these steps:

1. **Set up a `KubernetesCluster` resource**: This is the representation of our Kubernetes cluster in Digital Ocean. We provide specifications like the region, version, and the node pool details, which include the size and number of nodes in the cluster.

2. **Create a `Chart` resource for the Helm chart**: This represents the Helm chart we wish to deploy to our Kubernetes cluster. We must specify the chart name (in this case, "flask-app") and set any values that the chart requires.

Below is a step-by-step TypeScript program using Pulumi to deploy the `flask-app` Helm chart to a Digital Ocean Kubernetes Service cluster. Before running this code, ensure you have Pulumi and the `@pulumi/digitalocean` and `@pulumi/kubernetes` packages installed.

Here is the TypeScript program:

```typescript
import * as digitalocean from "@pulumi/digitalocean";
import * as kubernetes from "@pulumi/kubernetes";
import { Cluster } from "@pulumi/digitalocean/types/input";

// Create a DigitalOcean Kubernetes cluster.
const cluster = new digitalocean.KubernetesCluster("do-cluster", {
    region: "nyc1",
    version: "latest", // You can specify a fixed version instead of using "latest".
    nodePool: {
        name: "default",
        size: "s-2vcpu-2gb", // This is the size of the VM. Choose based on your requirements.
        nodeCount: 2, // Adjust the node count according to the expected workload.
    },
});

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

// Create a provider resource which uses the kubeconfig from our cluster to deploy resources into it.
const k8sProvider = new kubernetes.Provider("k8s-provider", {
    kubeconfig: kubeconfig,
});

// Deploy the "flask-app" Helm chart.
const flaskAppChart = new kubernetes.helm.v3.Chart("flask-app", {
    chart: "flask-app",
    // Here you can specify a repository if your chart is not in the default helm repo.
    // repo: "<your-helm-chart-repo>",
    values: {
        // Put any values here that your chart needs.
        // service: {
        //     type: "LoadBalancer",
        // },
        // image: {
        //     repository: "myrepo/flask-app",
        //     tag: "v1.0.0",
        // },
    },
}, { provider: k8sProvider });

// To ensure that you can connect to your app, you might want to export the service
// endpoint once it's ready. Note that depending on your service type, you may need
// to handle DNS and external IP addressing separately, and LoadBalancer type might
// take several minutes to get an external IP assigned.
```

Let's break down what this code does:

- We import the necessary Pulumi packages for DigitalOcean and Kubernetes.
- We declare a `KubernetesCluster` resource called "do-cluster" with `@pulumi/digitalocean`. This will request a new Kubernetes cluster from DigitalOcean with specific configurations such as the region, version, and size.
- The cluster's `kubeconfig` is exported. This contains the necessary information to connect to the Kubernetes cluster. This is sensitive information and should be handled securely.
- Using `@pulumi/kubernetes`, we create a provider using the above `kubeconfig` to interact with our Kubernetes cluster.
- Next, we declare a Helm chart resource with the `flask-app` Helm chart, which will be installed in the cluster provided by our custom Kubernetes provider. You may need to specify the location of your Helm chart in a chart repository, and adjust values according to the chart's requirements.
- Optionally, you can export endpoints or other important data after the chart is deployed, although this isn't shown in the code above.

To run this code, you would save it to a file called `index.ts`, then use the Pulumi CLI to create and execute a Pulumi project. Ensure that you have configured Pulumi with access to your DigitalOcean account, which typically involves setting up a DigitalOcean token as an environment variable or using `pulumi config`.

Remember that deploying cloud resources costs money and running Pulumi programs will affect your cloud billing. Always review the resources that will be created and their associated costs before proceeding with deployments.

Additionally, the Flask application Helm chart needs to be already packaged and available in a reachable Helm repository, or locally with its respective values adjusted for your specific deployment scenario. If the Helm chart is not packaged yet or you wish to reference a local directory, adjustments to the Helm chart configuration in the Pulumi program might be needed.