Deploy the hadoop-deployment helm chart on Rancher

Question

Pulumi · Accepted Answer

To deploy the `hadoop-deployment` Helm chart on Rancher, you would need to have a Rancher Kubernetes cluster already set up and accessible. The deployment will typically involve the following steps:

1. **Setting up the Rancher provider**: This initializes Pulumi's use of the `rancher2` provider so that it can manage resources in Rancher.
2. **Configuring the Helm chart**: You specify the settings for the `hadoop-deployment` Helm chart that you want to deploy. This may involve setting the chart version, any custom values to override the default chart settings, and the release name.
3. **Deploying the Helm chart**: Finally, you will deploy the Helm chart onto your Rancher cluster using Pulumi's Helm library.

Below is a Pulumi TypeScript program that demonstrates these steps. Before running this code, ensure that you have:
- Pulumi CLI installed.
- Rancher CLI configured with access to your Rancher server.
- Access to a Kubernetes cluster through Rancher.

Here's how the deployment with Pulumi looks like:

```typescript
import * as pulumi from '@pulumi/pulumi';
import * as k8s from '@pulumi/kubernetes';
import * as rancher2 from '@pulumi/rancher2';

// Initialize Rancher provider with the credentials/config necessary to access your Rancher server
const rancherProvider = new rancher2.Provider('rancherProvider', {
    // Generate an API key in Rancher and put it here
    apiToken: 'your-rancher-api-token',
    apiUrl: 'your-rancher-api-url',
});

// You can get the cluster ID by inspecting your cluster in Rancher UI or via Rancher CLI
const clusterId = 'your-rancher-cluster-id';

// Retrieve the cluster information from Rancher by ID
const cluster = rancher2.getCluster({
    id: clusterId,
}, {provider: rancherProvider});

// Now, configure the Kubernetes provider to deploy to the cluster from Rancher
const k8sProvider = new k8s.Provider('k8sProvider', {
    kubeconfig: cluster.kubeConfig,
});

// Define the Helm chart for the Hadoop deployment
const hadoopChart = new k8s.helm.v3.Chart('hadoop-deployment', {
    // If there's a specific chart repository, use repo: 'your-repo-url' in the arguments
    chart: 'hadoop',
    // Specify the Helm chart version you want to deploy
    version: 'your-chart-version',
    namespace: 'default', // Replace with the namespace where you want to deploy the chart
    // Set the values that configure the Hadoop Helm chart
    values: {
        // ... your Hadoop chart value overrides
    },
}, {provider: k8sProvider}); // Use the Rancher-derived Kubernetes provider for deploying the Helm chart

// To get outputs like the status of the Helm deployment
export const hadoopDeploymentStatus = hadoopChart.status;
```

In this program:
- Replace `'your-rancher-api-token'`, `'your-rancher-api-url'`, and `'your-rancher-cluster-id'` with the appropriate information from your Rancher setup.
- Replace `'your-chart-version'` with the version of the Helm chart you wish to deploy.
- Under `values`, specify any custom settings you need for your Hadoop deployment.

To run this code, save it in a file (for example, `index.ts`), navigate to the directory containing the file in your terminal, and execute `pulumi up`. Pulumi will then perform the deployment as specified. Make sure you have authenticated with Pulumi and the cloud provider.

This explanation assumes that you are already familiar with basic Kubernetes concepts and Helm charts. If you're not, here is a brief overview:

- A Kubernetes **Namespace** is a way to divide cluster resources between multiple users.
- A **Helm Chart** is a package composed of all of the resource definitions necessary to run an application, tool, or service inside of a Kubernetes cluster.
- The `values` in the Helm Chart allow you to customize the deployment configuration, which means you can set custom configuration without altering the chart itself.

Remember that the Helm chart must be available in a repository that your Rancher is configured to access, and you must have the permissions to deploy resources into the cluster managed by Rancher.