Deploy the hadoop-deployment helm chart on Kubernetes

Question

Pulumi · Accepted Answer

To deploy a Helm chart using Pulumi, you'll be leveraging the Pulumi Kubernetes provider. The Kubernetes provider plugin uses the Helm client to deploy charts, and it can work with existing Helm CLI configurations.

In this case, we'll use the `Chart` resource from Pulumi's Kubernetes provider to deploy the `hadoop-deployment` Helm chart onto a Kubernetes cluster. Before you begin, ensure you have access to a Kubernetes cluster and have the `kubeconfig` file configured for `kubectl` access.

Here's a step-by-step explanation of the Pulumi program:

1. **Import Required Pulumi Packages**:
   First, we import the necessary packages for our Pulumi program, which include `@pulumi/pulumi` for core Pulumi functionalities and `@pulumi/kubernetes` for the Kubernetes provider.

2. **Create a Helm Chart Resource**:
   We instantiate a `Chart` resource provided by Pulumi Kubernetes. This resource is a representation of a Helm chart in Pulumi's infrastructure as code. We need to specify the chart name, version (if specific one is desired), and any other custom values you want to override in the default chart configuration. If the Helm chart you're deploying is from a custom repository, you'd also need to provide the repository URL.

3. **Export Outputs** (optional):
   After deployment, if there are specific outputs you're interested in (like Service URLs, LoadBalancer IPs, etc.), you can export them using `pulumi.export`.

Below is the TypeScript program that deploys the `hadoop-deployment` Helm chart.

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

// Create a Kubernetes Namespace
const namespace = new k8s.core.v1.Namespace("hadoop-ns", {
    metadata: { 
        // Define metadata details if necessary.
        name: "hadoop-deployment",
    },
});

// Deploy the 'hadoop-deployment' helm chart into the created namespace
const hadoopChart = new k8s.helm.v3.Chart("hadoop-deployment", {
    namespace: namespace.metadata.name,
    chart: "hadoop",
    // Uncomment and specify the 'repo' attribute if your chart is hosted in a custom Helm repo
    // repo: "http://your-helm-chart-repository/",
    // Specify the chart version if necessary
    // version: "x.y.z",
    // Override default values by specifying your custom values
    // values: {
    //     "property": "value",
    // },
    // Make sure the chart is fetched before trying to install
    fetchOpts: {
        repo: "https://charts.bitnami.com/bitnami", // Assuming 'hadoop' chart is in bitnami's repository
    },
}, {
    provider: new k8s.Provider("k8s-provider", {
        // Set the kubeconfig if it is not already configured through the environment.
        // kubeconfig: "<kubeconfig-content>"
    }),
    // Specify that the chart should be installed only after the namespace has been created to avoid race conditions.
    dependsOn: [namespace],
});

// Export the Namespace name and Chart status
export const namespaceName = namespace.metadata.name;
export const hadoopChartStatus = hadoopChart.status;

```

Explanation of some important sections of the code:

- `Chart`: This resource is used to declare the deployment of the Helm chart. It's comparable to running `helm install` or `helm upgrade` commands.
- `namespace`: An optional resource to create a namespace where our chart will be deployed. This is good practice for organizational and security purposes.
- `fetchOpts`: In this hypothetical example, I'm assuming that the chart resides in the Bitnami Helm repository. You need to replace it with the correct repository where your `hadoop-deployment` chart is hosted.
- `provider`: A Pulumi `Provider` resource for Kubernetes allows you to specify the `kubeconfig` directly if it isn't already set up in your environment.

To use this Pulumi program, you should save this code to a file (for example `index.ts`) in a Pulumi project directory. Make sure to install the required packages using npm or yarn by running `npm install` or `yarn install` and then execute your Pulumi program with `pulumi up`.

Please replace the chart name, repository URL, and values with the correct ones for your `hadoop-deployment`. If there are specific settings or configurations that your Helm chart requires, you should include them in the `values` field, making sure the keys and values match what the Helm chart expects.