Deploy the rails helm chart on Linode Kubernetes Engine

Question

Pulumi · Accepted Answer

To deploy a Rails Helm chart on the Linode Kubernetes Engine (LKE), you will need to use the Pulumi Kubernetes provider. This provider allows you to define and manage Kubernetes resources using Pulumi.

Below is a Pulumi TypeScript program that demonstrates how to deploy a Rails application using the Helm chart. The program will do the following:

1. Import the necessary packages for Pulumi and Kubernetes.
2. Create a new Kubernetes Helm chart resource.
   - The chart, version, and repository URL need to be specific to the Rails Helm chart you want to use.
   - Typically, you need to set configuration values specific to your Rails application within the `values` property. Since this is an example, we'll assume default values will work, but you'll likely need to modify this for a real deployment.
3. Export any stack outputs you wish, like the public endpoint of your Rails application if applicable.

Before executing this program, you need to be authenticated to Linode and have your Kubernetes cluster configured. This means you should have `kubectl` installed and the kubeconfig file for your LKE cluster set up correctly on your development machine.

Here's the Pulumi TypeScript program:

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

// Specify the settings for the Helm chart.
const railsChart = new k8s.helm.v3.Chart("rails", {
    repo: "bitnami", // This is an example repository, change it to where your Rails Helm chart is located.
    chart: "ruby", // The 'ruby' chart can be used for Rails deployments. Change the chart name if needed.
    version: "2.0.0", // Specify the version of the Helm chart.
    // `values` provides the configuration for the chart. You'll need to provide your specific configuration.
    values: {
        /* For example, you might specify:
        image: {
            repository: "my-rails-app-image",
            tag: "latest",
        },
        service: {
            type: "LoadBalancer",
        },
        // Specify environment variables, database connections, etc.
        */
    },
});

// Export the URL for the Rails application.
// This depends on how your Rails Helm chart exposes the application.
export const appUrl = railsChart.getResourceProperty("v1/Service", "rails-ruby", "status")
    .apply(status => status.loadBalancer.ingress[0].ip || status.loadBalancer.ingress[0].hostname);
```

Be sure to update the `repo`, `chart`, `version`, and `values` with the correct information for your specific Rails Helm chart.

To apply this Pulumi program, you'll use the Pulumi CLI:

```bash
# Login to the Pulumi service
pulumi login

# Create a new Pulumi stack, which is an isolated environment for your project
pulumi stack init my-lke-stack

# Install the node modules
npm install

# Preview the deployment of the resources
pulumi up --yes

# After confirming the preview looks correct, Pulumi will proceed with the deployment.
```

Keep in mind, you'll need to fill in the `values` field with the configuration that matches the needs of your Rails application. This can include database configurations, environment variables, storage options, and more. You can find more details about the configuration options for Helm charts in the chart's documentation or by using the `helm show values CHART` command.