Deploy the elastalert helm chart on Linode Kubernetes Engine

Question

Pulumi · Accepted Answer

To deploy the ElastAlert Helm chart on Linode Kubernetes Engine (LKE) using Pulumi, you'll first need to set up a Kubernetes cluster in LKE. Afterward, you can deploy ElastAlert using a Helm chart.

Below is a program in TypeScript which outlines the steps required to accomplish this:

1. Set up an instance of an LKE cluster using Pulumi.
2. Use the Helm Chart resource to deploy ElastAlert onto the LKE cluster.

The following program assumes that you have Linode provider and Kubernetes provider set up with their respective configurations (e.g., token, kubeconfig). Note that we are not covering the setup of the Linode provider and authentication as these would typically be environment-specific and configured outside of the Pulumi program.

First, you will need to import the necessary Pulumi libraries for the Kubernetes and Linode providers:

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

Next, you'll create the LKE cluster. When this cluster is provisioned, you'll use the output of the cluster's kubeconfig to configure the Kubernetes provider:

```typescript
// Create a Linode Kubernetes Engine cluster.
const cluster = new linode.LkeCluster("my-cluster", {
    region: "us-central",
    k8sVersion: "1.20",
    nodePools: [{
        type: "g6-standard-2",
        count: 3,
    }],
});

// Export the kubeconfig of the cluster.
export const kubeconfig = cluster.kubeconfig;
```

Once you have your LKE cluster up and running, you'll use the kubeconfig to install the ElastAlert Helm chart:

```typescript
// Initialize a Kubernetes provider using the kubeconfig from the LKE cluster.
const k8sProvider = new k8s.Provider("k8s", {
    kubeconfig: cluster.kubeconfig.apply(JSON.stringify),
});

// Deploy the ElastAlert Helm chart.
const elastalertChart = new k8s.helm.v3.Chart("elastalert", {
    chart: "elastalert",
    version: "1.7.0", // Specify the version of the Helm chart you wish to deploy
    fetchOpts:{
        repo: "https://helm.elastalert.com" // Location of the ElastAlert Helm repository
    },
}, { provider: k8sProvider });

// Export the ElastAlert deployment's namespace and service name for reference.
export const elastalertNamespace = elastalertChart.namespace;
export const elastalertServiceName = elastalertChart.getResourceProperty("v1/Service", "elastalert", "metadata").apply(m => m.name);
```

This code block creates an instance of your LKE cluster, establishes a Kubernetes provider to interact with the cluster, and then deploys ElastAlert using its Helm chart. Remember to replace the `version` with the ElastAlert Helm chart version that you intend to use.

To execute this Pulumi program, save it to a file with the `.ts` extension, for example, `deployElastAlert.ts`. To apply the program, use the Pulumi CLI commands `pulumi up` in the same directory as your `.ts` file. This will initiate the cluster creation and Helm chart deployment. Ensure that you have the Pulumi CLI installed and configured for use with Linode.

After running the deployment, you can monitor ElastAlert by using `kubectl` to interact with the Kubernetes cluster managed by LKE. Use the exported `elastalertNamespace` and `elastalertServiceName` to find the right resources in your Kubernetes cluster.