Deploy the basic helm chart on Kubernetes

Question

Pulumi · Accepted Answer

Deploying a Helm chart on a Kubernetes cluster using Pulumi involves several steps, but essentially you need to have a Kubernetes cluster configured, and Pulumi needs access to that cluster to manage the Helm chart deployments. Below, I'll walk you through the Pulumi program that deploys a basic Helm chart into an existing Kubernetes cluster.

The resource we'll use to achieve this is `kubernetes.helm.v3.Chart`. This is a Pulumi resource that represents a Helm chart from either a public or private repository (or even from a local path). It will take care of fetching the Helm chart and applying it to the configured Kubernetes cluster.

In this example, we don't specify the cluster because Pulumi uses the default Kubernetes context from your local `~/.kube/config` file. If you're running this in an environment where you want to specify a different context or a kubeconfig file, you need to configure Pulumi’s Kubernetes provider accordingly.

Here's the TypeScript program to deploy a basic Helm chart:

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

// Define the Helm chart repository and the chart details.
const chart = new k8s.helm.v3.Chart("nginx", {
    chart: "nginx",
    version: "1.16.0", // specify the version of the chart you want to deploy
    fetchOpts: {
        repo: "https://charts.bitnami.com/bitnami", // URL of the Helm repository
    },
    // Values to provide to the Helm chart. These values would be the equivalent
    // of what you'd put in a values.yaml file for configuration.
    values: {
        service: {
            type: "LoadBalancer",
        },
    },
});

export const chartName = chart.metadata.apply(metadata => metadata.name);
```

This code does the following:

1. It imports the necessary Kubernetes package from Pulumi.
2. It creates a new Helm chart resource in Pulumi, called `nginx`.
3. The `chart` property identifies the name of the chart we want from the repository.
4. The `version` property specifies which version of the chart you want to deploy.
5. The `repo` url within `fetchOpts` defines which Helm repository to source the chart from.
6. `values` are the chart's configurable options. These are equivalent to overrides you might provide in a custom `values.yaml` file.
7. The exported `chartName` will display the name of the Helm chart once it is deployed.

This code assumes you have access to the cluster through `kubectl` and have previously installed `@pulumi/kubernetes` npm package with `npm install @pulumi/kubernetes`.

Please note that in real scenarios, your configuration might require additional parameters such as `namespace` if you want to target a specific namespace, and you can provide a long list of overrides within `values` to customize your Helm chart as required.

When you run this Pulumi program, it will invoke the necessary Helm commands to deploy the chart onto your Kubernetes cluster. If this is the first time you are running it, Pulumi will perform a `helm install`, and on subsequent runs, it will automatically handle `helm upgrade` or `helm delete` as necessary.