Deploy the java helm chart on Kubernetes

Question

Pulumi · Accepted Answer

Deploying a Helm chart on a Kubernetes cluster using Pulumi involves several steps. The Pulumi program below demonstrates this process using TypeScript.

First, let's discuss what we're doing:

We're creating a Kubernetes Helm Chart resource using the `kubernetes.helm.v3.Chart` class from Pulumi's Kubernetes provider. To do this, we need a pre-existing Kubernetes cluster where the Helm chart will be deployed.

In the code, you'll see how we set up the `Chart` resource, specifying the chart details such as the chart name (e.g., 'java'), repository URL where the chart can be found, and version of the chart if applicable. Additionally, we can provide a set of values to customize the deployment, which would be equivalent to the `values.yaml` file used in Helm.

This example assumes that you have already configured Pulumi for your Kubernetes cluster, for example by using `pulumi config set kubernetes:context <your-cluster-context>` command or by setting default context in your kubeconfig file.

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

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

// Instantiate your Kubernetes Helm Chart here.

// Chart() takes the following arguments:
// - releaseName: a name for your release (deployment) of the Helm chart
// - args: contains all the specific information for the chart, including the chart name (`chart`),
//   the repository where the chart is hosted (`repo`), and any specific version (`version`) if needed.
//   `values` is an object that holds configuration values for the chart, similar to helm's values.yaml.

const javaChart = new kubernetes.helm.v3.Chart("java-helm-chart", {
  chart: "java", // Replace with your actual chart name
  version: "0.1.0", // Specify the chart version, if known.
  fetchOpts: {
    repo: "https://charts.example.com/repository", // Replace with the actual chart repo URL
  },
  // Include any custom values you want to pass into the chart.
  values: {
    serviceType: "ClusterIP",
    // Add other values here as needed
  },
});

// Export the resulting base URL of the Service.
export const javaBaseUrl = javaChart.getResourceProperty(
  "v1/Service", "java-helm-chart", "status"
).apply(status => `http://${status.loadBalancer.ingress[0].hostname}`);

```

Let's discuss the critical parts of the code:

- `import * as kubernetes from '@pulumi/kubernetes';`: This line imports the Pulumi Kubernetes plugin, which we use to describe the Kubernetes resources.

- `const javaChart = new kubernetes.helm.v3.Chart("java-helm-chart", {...})`: This creates a new Helm chart resource using the Helm chart for Java. You need to replace placeholder values like `chart`, `repo`, and `version` with actual values specific to the Java chart you want to deploy. The `values` block inside `args` allows you to customize the deployment by setting the desired properties, similar to how you'd configure them in the Helm chart's `values.yaml` file.

- `export const javaBaseUrl = ...`: This line exports an important URL from our deployment, allowing us to access the service externally if it's set to use a LoadBalancer type. It assumes that the chart deploys a service resource and that we can extract its status.

To run this Pulumi program:

1. Save this TypeScript code to a file named `index.ts` within a new Pulumi project directory.
2. Ensure that you have Pulumi and Node.js installed.
3. Run the `pulumi up` command to preview and deploy the chart.

Remember, Helm charts may include various Kubernetes resources, and their composition and required configuration will vary. Always refer to the specific Helm chart's documentation for the requisite values and configurations.

Keep in mind that Helm charts and Kubernetes clusters come in many configurations. The above is a simplified example, and additional steps, such as setting up RBAC (Role-Based Access Control), may be required depending on your cluster setup and the specifics of the chart you're deploying.