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

Question

Pulumi · Accepted Answer

To deploy the Prometheus Alerts Helm chart on the Digital Ocean Kubernetes Service (DOKS), you would need the following steps:

1. Create a DOKS cluster, which is the Kubernetes cluster in the Digital Ocean environment where your applications will be deployed.
2. Install the Prometheus Helm chart on this cluster to monitor your Kubernetes cluster and raise alerts based on the configured rules.

To accomplish this, we will write a Pulumi program in TypeScript. Pulumi allows you to define infrastructure as code using real programming languages. In this case, we're using TypeScript to define the Kubernetes cluster on DigitalOcean and deploying the Helm chart for Prometheus Alerts.

Before creating any resources, ensure you have the following prerequisites:
- A Digital Ocean account and access token.
- The Pulumi CLI installed and configured with your Digital Ocean token.

Here's a step-by-step Pulumi program using TypeScript:

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

// Define the configuration for your DigitalOcean Kubernetes cluster:
const cluster = new digitalocean.KubernetesCluster("do-cluster", {
    region: digitalocean.Regions.NYC3,
    version: "latest",
    nodePool: {
        name: "default",
        size: digitalocean.DropletSlugs.DOS3VCPU8GB,
        nodeCount: 2,
    },
});

// Once the cluster is provisioned, we can configure the Kubernetes provider to deploy resources to it:
const k8sProvider = new kubernetes.Provider("k8s-provider", {
    kubeconfig: cluster.kubeConfigs[0].rawConfig,
});

// Define the configuration for the Prometheus Alerts Helm chart:
const prometheusAlertsChart = new kubernetes.helm.v3.Chart("prometheus-alerts", {
    chart: "prometheus",
    fetchOpts:{
        repo: "https://prometheus-community.github.io/helm-charts",
    },
    // Specific values can be customized based on the Helm chart requirements
    values: {
        // You can set values like alerting rules, storage configurations, etc.
    },
}, { provider: k8sProvider });

// Export the Cluster's kubeconfig and the Prometheus endpoint to access the dashboard:
export const kubeconfig = cluster.kubeConfigs[0].rawConfig;
export const prometheusEndpoint = pulumi.interpolate`http://${prometheusAlertsChart.getResourceProperty("v1/Service", "prometheus-alerts-server", "status").apply(s => s.loadBalancer.ingress[0].ip)}:9090`;
```

Cluster creation will take a few minutes. After that, the Prometheus Alerts Helm chart is deployed to the created DOKS cluster.

Explanation of Resources in the Program:

1. `digitalocean.KubernetesCluster`: This creates a Kubernetes cluster on Digital Ocean. We configure it with the name "do-cluster", assign it to a region, specify the Kubernetes version, and define the node pool with its size and count.

2. `kubernetes.Provider`: This configures the Kubernetes provider with the created cluster's kubeconfig so that Pulumi knows where to deploy Kubernetes resources.

3. `kubernetes.helm.v3.Chart`: This is the Pulumi resource that deploys a Helm chart. We're specifying the "prometheus" chart from the Prometheus community Helm repository.

4. Exports: The `kubeconfig` is exported so you can interact with your Kubernetes cluster using `kubectl` or any other Kubernetes tool. The `prometheusEndpoint` is the access point for the Prometheus server, allowing you to access the Prometheus dashboard to monitor your alerts and metrics.

To apply this configuration, run the following commands:

```shell
pulumi up
```

This will prompt you to confirm the deployment after showing you the resources that will be created.

Remember, maintaining sensitive data like kubeconfigs within your code is not recommended for production scenarios. Use Pulumi's secret management or environment variables for this purpose.