Deploy the echoserver helm chart on Kubernetes

Question

Pulumi · Accepted Answer

In this Pulumi program, we will deploy the 'echoserver' Helm chart on a Kubernetes cluster. Helm charts are packages for Kubernetes resources, which allow for easier management and deployment of applications on Kubernetes. The 'echoserver' Helm chart we'll be deploying is a simple server that echoes back the HTTP headers, request method, URL, and body of requests it receives, which is useful for debugging or testing.

To deploy a Helm chart using Pulumi, you need to have access to a Kubernetes cluster and the Helm CLI installed. Pulumi provides an abstraction for Helm charts through the `Chart` class in the Kubernetes provider, allowing you to deploy charts in a manner similar to how you would using the `helm` command-line tool.

The `kubernetes.helm.v3.Chart` resource is used to deploy the Helm chart to your Kubernetes cluster from a remote repository. The properties `repo`, `chart`, and `version` specify the repository, chart name, and version of the chart you want to deploy, respectively.

Below is a Pulumi program written in TypeScript that deploys the 'echoserver' Helm chart to a Kubernetes cluster. Before you run this Pulumi program, ensure you have the following prerequisites:

1. Pulumi CLI installed and logged in.
2. Access to a Kubernetes cluster. You can use any existing Kubernetes cluster or create one.
3. Your `kubeconfig` file is correctly set up to connect to your cluster.

Here's the TypeScript Pulumi program:

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

// Create an instance of the Helm chart "echoserver". This assumes that you already have a Kubernetes cluster up and running and Pulumi is configured to connect to it.
const echoserver = new k8s.helm.v3.Chart("echoserver", {
    // You can specify the version of the Helm chart you want to deploy. For the latest version, omit the 'version' property.
    version: "1.10.0",  // Replace with the desired chart version.
    chart: "echoserver",
    // The repository where the Helm chart is hosted. This URL points to the Helm chart repository containing the 'echoserver' chart.
    repo: "https://pulumi.github.io/pulumi-kubernetes",
    // Any custom values you want to pass to the Helm chart. This is equivalent to Helm's '--set' command line parameter.
    values: {
        service: {
            type: "ClusterIP"
        }
    },
    // Namespace to deploy the Helm chart into. If omitted, the Helm chart will be deployed into the 'default' namespace.
    namespace: "default", 
});

// To access the service, you would typically use `kubectl port-forward` to forward a local port to the echoserver service on the cluster or set the service type to `LoadBalancer` if your cloud provider supports it.
// For this example, we just export the service name which you can use to interact with Services in your Kubernetes cluster.
export const serviceName = echoserver.getResourceProperty("v1/Service", "echoserver-echoserver", "metadata").apply(m => m.name);
```

After writing the above program in a TypeScript file (e.g., `index.ts`), you can run it using the Pulumi CLI. Here's how you would typically run the Pulumi program:

1. Initialize a new Pulumi project in your working directory.
   ```sh
   pulumi new typescript --dir my-echoserver
   ```
   Follow the prompts to configure your project. You can choose 'no' when asked to create a stack.

2. Replace the content of `index.ts` in the `my-echoserver` directory with the code provided above.

3. Navigate to your project directory and install dependencies:
    ```sh
    cd my-echoserver
    npm install
    ```

4. Run the Pulumi program to deploy the chart to your Kubernetes cluster:
    ```sh
    pulumi up
    ```

5. Follow the prompts from Pulumi to preview and apply the changes. It might take a few moments to complete, after which Pulumi will output the name of the service created.

Remember to replace the `version` and `repo` properties with the correct values for the Helm chart you want to deploy. If you wish to deploy a different Helm chart or another version, you may need to update the `chart`, `version`, and `repo` to the correct values that point to the Helm chart you want to deploy.

By running the Pulumi program, the specified version of the 'echoserver' chart gets deployed, and the service can then be accessed within the cluster. If you wish to make the 'echoserver' accessible externally, you can use port-forwarding, create an Ingress resource, or change the service type to `LoadBalancer` depending on your environment and cloud provider capabilities.