Deploy the prometheus-alerts helm chart on Linode Kubernetes Engine

Question

Pulumi · Accepted Answer

To deploy the Prometheus alerts Helm chart on Linode Kubernetes Engine using Pulumi, we will perform the following steps:

1. **Set up a Kubernetes cluster**: We will create a Kubernetes cluster on Linode using Pulumi's Linode provider. However, as of my knowledge cutoff in early 2023, Pulumi does not have a dedicated Linode Kubernetes Engine (LKE) resource. Assuming the situation has not changed, you would typically set up your Linode Kubernetes cluster through the Linode Cloud Manager or using Terraform with the Linode Terraform provider and import it into Pulumi.

2. **Configure the Kubernetes provider**: Once we have the cluster, we'll configure Pulumi to use the Kubernetes provider to interact with the cluster.

3. **Deploy the Helm chart**: We'll deploy the Prometheus alerts Helm chart using the Pulumi Kubernetes provider's `Chart` resource, which allows us to specify Helm charts to deploy.

Let's start coding. First, we will start with creating a Kubernetes cluster, but since we are creating a demonstration, and there's no native Linode Kubernetes Engine (LKE) resource in Pulumi yet, we will use a mock cluster resource and import configuration as an example. Please replace this step with the actual provisioning of a Linode Kubernetes cluster or importing an existing cluster before proceeding.

Then, we will configure the Kubernetes provider using the output of the cluster, particularly focusing on the kubeconfig data that is necessary for Pulumi to interact with our Kubernetes cluster.

Finally, we will deploy the Prometheus alerts Helm chart by specifying the required chart values. This step assumes that the "prometheus-alerts" Helm chart is available in a Helm repository. If it isn't, you will need to provide the appropriate Helm repository URL and any necessary authentication credentials.

Here is the TypeScript program that accomplishes this:

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

// Step 1: Configure your cluster here (mock example).
// Note: Replace this with actual cluster provisioning code or import.
const cluster = new k8s.core.v1.Namespace("lke-cluster-mock", {
  // In reality, you would have more information about your cluster here.
  metadata: { name: "linode-cluster" },
});

// Export the kubeconfig from the cluster.
const kubeconfig = pulumi.output(cluster.metadata.name); // Mock output, replace with real kubeconfig.

// Step 2: Set up the Kubernetes provider using the kubeconfig from the cluster.
// This provider is then used to interact with the Kubernetes cluster.
const provider = new k8s.Provider("k8s-provider", {
  kubeconfig: kubeconfig,
});

// Step 3: Use Pulumi to deploy the Prometheus alerts Helm chart.
const prometheusChart = new k8s.helm.v3.Chart("prometheus-alerts", {
  chart: "prometheus-alerts",
  version: "x.y.z", // Replace with the chart version you want to deploy.
  // Add your Helm repository here if it's not in the default Helm repo.
  // If your Helm chart requires a specific namespace, set it here.
  // namespace: "monitoring",
  // If needed, provide the Helm values file or configure values inline.
  // values: { ... },
}, { provider });

// Export the status of the Helm deployment.
export const prometheusChartStatus = prometheusChart.status;
```

Please note the following important points:

- The Pulumi program above is a framework. You need to replace the mock objects and placeholder code with actual values from your configuration, like the cluster details and the specifics of the Helm chart.
  
- The `kubeconfig` must contain the credentials to access your Linode Kubernetes cluster. This is normally sensitive information and should be handled securely.

- The version of the Helm chart specified in `version: "x.y.z"` should be the actual version you wish to deploy. This information can be found in the Helm repository where the chart is hosted.

- If your Helm chart requires you to provide a values file or set configuration parameters, you should add those as properties in the `values: { ... }` construct.

This program provides a foundation to deploy not just the Prometheus alerts chart, but any Helm chart, to your Kubernetes cluster on Linode. Ensure to review and customize it to fit the specifics of the Helm chart you want to deploy and the configuration of your cluster.