Deploy the prometheus-alertmanager helm chart on Digital Ocean Kubernetes Service

Question

Pulumi · Accepted Answer

In the following Pulumi TypeScript program, you'll see how to deploy the Prometheus Alertmanager using a Helm chart on the Digital Ocean Kubernetes Service. This use case involves two primary resources: a Digital Ocean Kubernetes cluster and a Helm chart representing the Prometheus Alertmanager application.

Firstly, you'll need to set up a Digital Ocean Kubernetes cluster which will provide the runtime environment for the Alertmanager. Once the cluster is provisioned, you'll then deploy the Prometheus Alertmanager using a Helm chart. Prometheus Alertmanager handles alerts sent by client applications such as the Prometheus server.

Before running the following program, make sure you have the Pulumi CLI installed and have authenticated with Digital Ocean. You will also need `kubectl` to interact with your Kubernetes cluster and Helm for packaging the applications to deploy.

Here is how you can set up and deploy the Prometheus Alertmanager to a Digital Ocean Kubernetes Service using Pulumi:

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

// Create a Digital Ocean Kubernetes cluster
const cluster = new digitalocean.KubernetesCluster('do-cluster', {
    region: digitalocean.Regions.SFO2, // Replace with your preferred region
    version: 'latest', // Use the latest available version
    nodePool: {
        name: 'default', // Assign a name to the node pool, you can choose
        size: digitalocean.DropletSlugs.DropletS2VCPU2GB, // Choose an appropriate droplet size
        nodeCount: 2, // The number of nodes in the pool
    },
});

// Export the Kubeconfig and cluster ID
export const kubeconfig = cluster.kubeConfigs[0].rawConfig;
export const clusterId = cluster.id;

// Helm chart for Prometheus Alertmanager
const alertmanagerChart = new kubernetes.helm.v3.Chart('alertmanager', {
    chart: 'prometheus-alertmanager',
    fetchOpts:{
        repo: 'https://prometheus-community.github.io/helm-charts',
    },
    namespace: 'monitoring', // Specify the namespace where you want to deploy
    // If necessary, you can specify additional values to customize the deployment
    // values: { 
    //     ...
    // },
}, { provider: new kubernetes.Provider('k8s-provider', { kubeconfig: cluster.kubeConfigs[0].rawConfig }) });

// Export the name of the chart
export const alertmanagerChartName = alertmanagerChart.metadata.apply(m => m.name);

```

In this program:
- We first import the necessary Pulumi libraries.
- We then declare a Digital Ocean Kubernetes cluster with a given region, version, and node pool configuration. You can customize the region, Droplet type, and number of nodes as required.
- The `kubeconfig` for the cluster and `clusterId` are exported. These values can be used to interact with the cluster outside Pulumi if required.
- For deploying Prometheus Alertmanager, we declare a `Chart` resource from the `@pulumi/kubernetes` library and provide the necessary parameters. We are using the Helm chart `prometheus-alertmanager` from the official Prometheus-community Helm chart repository.
- We pass a newly created Kubernetes provider to the `Chart` resource, which uses the `kubeconfig` of the Digital Ocean Kubernetes cluster we set up earlier.
- Finally, the name of the deployed chart is exported so that it can be referenced if needed.

To run this Pulumi program:
1. Save the code to a file named `index.ts`.
2. Run `pulumi up` in the terminal in the same directory as your `index.ts` file. Pulumi will perform the deployment and show you the progress.

Please ensure you have configured Pulumi with your Digital Ocean token and set up the Digital Ocean provider. Information about how to configure Pulumi for Digital Ocean can be found in the [Pulumi Digital Ocean documentation](https://www.pulumi.com/docs/intro/cloud-providers/digitalocean/setup/).

Additionally, you should also familiarize yourself with the specifications of the Prometheus Alertmanager Helm Chart which you can find on [ArtifactHUB](https://artifacthub.io/packages/helm/prometheus-community/prometheus-alertmanager) or directly on the [GitHub repository](https://github.com/prometheus-community/helm-charts/tree/main/charts/alertmanager). This can be particularly useful if you need to provide custom values or configurations to the Helm chart.