Deploy the cassandra-web helm chart on Kubernetes

Question

Pulumi · Accepted Answer

To deploy the `cassandra-web` Helm chart on a Kubernetes cluster using Pulumi, we'll leverage the `@pulumi/kubernetes` package which allows us to interface with Kubernetes resources, including Helm charts. For this task, we use the `Chart` resource, which is a higher-level construct that simplifies deploying Helm charts.

Firstly, ensure you have Pulumi installed and set up along with the necessary Kubernetes context configured to point to your cluster. If you're using a cloud provider's managed Kubernetes service (like GKE, EKS, or AKS), make sure that the kubeconfig file is correctly set up on your machine or in the environment where Pulumi will run.

Here's a step-by-step TypeScript program to deploy the `cassandra-web` Helm chart:

1. **Setting up a Pulumi Project**: Create a new Pulumi project and install the necessary packages.

2. **Writing the Pulumi Program**: Write the TypeScript program in a file (e.g., `index.ts`) within the Pulumi project.

3. **Executing the Program**: Run `pulumi up` to preview and deploy the resources.

### Pulumi Program to Deploy a Helm Chart

Before you proceed with the following TypeScript program, make sure to install the `@pulumi/kubernetes` package by running:
```bash
npm install @pulumi/kubernetes
```

Now, let's create a file `index.ts` with the following content:

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

// Create an instance of the kubernetes.helm.v3.Chart class to deploy the cassandra-web Helm chart.
const cassandraWebChart = new k8s.helm.v3.Chart("cassandra-web", {
    // Define the properties required by the Chart resource:
    chart: "cassandra-web", // This is the name of the chart.
    // Optional: Specify the Helm chart version you want to deploy. Omit or set to undefined to get the latest version.
    version: "x.x.x", // Replace 'x.x.x' with the specific chart version you want.
    // Optional: If the Helm chart is not from the default repository, provide a repository URL.
    // repo: "URL of the Helm chart repository",
    // Optional: Provide any custom values to the Helm chart.
    // values: {
    //   key: "value",
    // },
});

// Export the public IP or hostname of the service to access cassandra-web
export const cassandraWebEndpoint = cassandraWebChart.getResourceProperty("v1/Service", "cassandra-web", "status").apply(status => {
    // Depending on the service type, you may have a different field than 'loadBalancer.ingress[0].ip'.
    // For example, you might have 'loadBalancer.ingress[0].hostname' instead.
    return status.loadBalancer?.ingress[0]?.ip ?? "Not Assigned";
});
```

Make sure to replace `"x.x.x"` with the version of the `cassandra-web` chart you want to deploy if you know that already; otherwise, Pulumi will attempt to deploy the latest version by default.

### Explanation

- We import the Pulumi Kubernetes package which provides us with the APIs needed to interact with Kubernetes.

- We instantiate a `Chart` with the name `cassandra-web`, which is the identifier Pulumi will use to track the resource in its state.

- The `chart` property specifies the name of the Helm chart we want to deploy. In this case, it's `cassandra-web`.

- The `version` property sets the version of the chart to be deployed. This is optional; if you do not specify it, Pulumi will use the latest version available in the repository.

- The `repo` is where you can specify the URL of the Helm repository if you're using a chart that is not hosted in the default Helm repository. This is also optional and should be used when the chart is in a custom Helm repository.

- The `values` is a key-value map representing any custom configurations to override the defaults in the Helm chart. This is optional.

- Lastly, we have an export statement that gives us the public endpoint of the `cassandra-web` service after it's deployed. Depending on the type of service and how it's configured (e.g., LoadBalancer, NodePort, etc.), you might need to change the field accessed in `.apply`.

When you run `pulumi up`, the program will interact with your configured Kubernetes cluster and deploy the `cassandra-web` Helm chart. The Pulumi CLI will display the progress of the deployment and provide you with the information about created resources along with any errors that might occur during deployment.

Remember, you'll need to set up your `kubeconfig` correctly so Pulumi can access and manage resources in your Kubernetes cluster.