Deploy the elastalert helm chart on Digital Ocean Kubernetes Service

Question

Pulumi · Accepted Answer

To deploy the ElastAlert Helm chart on a Digital Ocean Kubernetes Cluster using Pulumi, you'll need to complete the following steps:

1. Set up a new Pulumi project and configure it for use with DigitalOcean.
2. Create a Kubernetes cluster on DigitalOcean.
3. Install the Helm chart for ElastAlert on the newly created Kubernetes cluster.

I will guide you through the TypeScript code needed to accomplish these steps with Pulumi.

### Setting Up a Pulumi Project

Before you begin writing the code, you should have a Pulumi project set up. To create a new Pulumi project, run `pulumi new typescript` and follow the prompts. This command creates a new directory with a `Pulumi.yaml` containing project information and an empty `index.ts` file where you'll place your code. Ensure you have the DigitalOcean API token set in your environment or Pulumi configuration so that Pulumi can authenticate with your DigitalOcean account.

### Creating a Digital Ocean Kubernetes Cluster

The first resource to create is the Kubernetes cluster on DigitalOcean. You will use the `digitalocean.KubernetesCluster` resource for this purpose. This resource allows you to define the size, region, and other configurations for your cluster.

### Installing the Helm Chart

After creating the cluster, you will need to deploy the ElastAlert Helm chart onto it. You'll use Pulumi's `Chart` resource from its Kubernetes package to accomplish this. This resource is designed to work with Helm charts and can be configured with the desired chart's repository and version.

Below you'll find a Pulumi program written in TypeScript. It creates a Digital Ocean Kubernetes cluster and then deploys the ElastAlert Helm chart onto it.

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

// Configuration variables for the Digital Ocean Kubernetes cluster
const clusterName = 'elastalert-cluster';
const region = 'nyc1'; // Choose the region appropriate for you
const nodeSize = 's-1vcpu-2gb'; // Choose the node size that fits your needs

// Create a Kubernetes cluster on DigitalOcean
const cluster = new digitalocean.KubernetesCluster(clusterName, {
    // Assigning a name to our cluster
    name: clusterName,
    // Selecting the region for our cluster
    region: region,
    // Defining the version of Kubernetes to use. It's recommended to use the latest supported version
    version: digitalocean.getKubernetesVersions({region: region}).then(p => p.latestVersion),
    // Defining the node pool for the cluster
    nodePool: {
        name: "worker-pool",
        size: nodeSize,
        nodeCount: 2, // Number of nodes (Choose the number based on your load requirements)
    },
});

// Export the Kubeconfig file for the Digital Ocean Kubernetes cluster
export const kubeconfig = cluster.kubeConfigs.apply(kc => kc[0].rawConfig);

// Create a Kubernetes Provider instance using the exported kubeconfig
const k8sProvider = new kubernetes.Provider("k8s-provider", {
    kubeconfig: kubeconfig,
});

// Deploy the ElastAlert Helm chart on the Digital Ocean Kubernetes cluster
const elastAlertChart = new kubernetes.helm.v3.Chart("elastalert", {
    chart: "elastalert",
    version: "1.13.0", // Replace with the desired chart version
    fetchOpts:{
        repo: "https://helm.elastalert.com/", // Url may change, please ensure it's up to date
    },
}, { provider: k8sProvider });

// Export the endpoint of the ElastAlert service
export const elastAlertEndpoint = elastAlertChart.getResourceProperty("v1/Service", "elastalert", "status")
    .apply(status => status.loadBalancer.ingress[0].ip);
```

**Explanation of the Pulumi Program:**

The program above completes the deployment in three steps:

1. It creates a new Kubernetes cluster in the specified DigitalOcean region. The cluster name, region, and node size are defined as configuration variables for easy adjustment. The node count is specified in the `nodePool` object; this should be tailored to your expected workload.

2. Once the cluster is ready, the program exports the kubeconfig, which Pulumi automatically generates to interact with your new Kubernetes cluster.

3. With the kubeconfig, the program then creates a Pulumi Kubernetes Provider, which allows Pulumi to deploy applications onto the cluster.

4. Finally, using the Kubernetes provider, the program deploys ElastAlert using a Helm chart. The chart name and version are provided, and also the repository from which the Helm chart is fetched.

Note that the version and the repository URL are placeholders and they should reflect the current available version and the correct URL when you create the deployment.

After the deployment, the program exports the endpoint for the ElastAlert service, which can be used to interact with ElastAlert once it's up and running. When you run this Pulumi program with `pulumi up`, Pulumi automatically provisions the DigitalOcean Kubernetes cluster and deploys the ElastAlert Helm chart as specified.