Deploy the helm-mongodb-operator helm chart on Digital Ocean Kubernetes Service

Question

Pulumi · Accepted Answer

To deploy the `helm-mongodb-operator` Helm chart on a Digital Ocean Kubernetes Service (DOKS), we need to perform a few steps with Pulumi.

1. **Create a DigitalOcean Kubernetes Cluster**: First, we use the `digitalocean.KubernetesCluster` resource to provision a new Kubernetes cluster on Digital Ocean. This resource allows us to define the size, name, region, version, node count, and other properties of our Kubernetes cluster.

2. **Install the Helm Chart**: Once the cluster is up and running, we then employ the `kubernetes.helm.v3.Chart` resource from Pulumi's Kubernetes provider to deploy the Helm chart to the cluster. We specify the chart name (`helm-mongodb-operator`), the repository URL (if it is not a stable chart that Helm already knows about), and any additional configurations required by the chart.

Here's how you could write a Pulumi program in TypeScript to achieve the deployment:

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

// Define config values for the DigitalOcean Kubernetes cluster
const config = new pulumi.Config();
const clusterName = config.require('clusterName');
const region = config.require('region');
const nodeSize = config.require('nodeSize');
const nodeCount = config.requireNumber('nodeCount');

// Create a DigitalOcean Kubernetes cluster
const cluster = new digitalocean.KubernetesCluster(clusterName, {
    region: region,
    version: "latest", // This will use the latest available version of Kubernetes
    nodePool: {
        name: "default",
        size: nodeSize,
        nodeCount: nodeCount
    }
});

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

// Once the cluster is provisioned, we can use KubeConfig to connect our Kubernetes provider to it.
const k8sProvider = new kubernetes.Provider("k8sProvider", {
    kubeconfig: cluster.kubeConfigs[0].rawConfig,
});

// Deploy the helm-mongodb-operator Helm chart
const mongodbOperatorChart = new kubernetes.helm.v3.Chart("mongo-operator", {
    chart: "helm-mongodb-operator",
    // Assuming helm-mongodb-operator is available in the default repo,
    // otherwise, you'd specify a `repo` attribute here.
    // For example: repo: "https://charts.bitnami.com/bitnami"
    values: {
        // Specify any custom values for the Helm chart here
    },
}, { provider: k8sProvider });

// Export the endpoints
export const mongoDashboard = pulumi
    .all([cluster.endpoint, mongodbOperatorChart.ready])
    .apply(([endpoint, _]) => `http://${endpoint}`);

```

Let's explain what the code does:

- We import three relevant Pulumi packages: `@pulumi/pulumi`, `@pulumi/digitalocean`, and `@pulumi/kubernetes`.

- We declare configurations for the DigitalOcean Kubernetes cluster, which are values that are read from the Pulumi configuration system or included in the Pulumi stack's configuration file.

- We declare a new DigitalOcean Kubernetes cluster with preferred settings (region, version, node size, node count).

- We export two essential variables, `kubeconfig` and `clusterId`, which can be used to interact with the cluster outside of Pulumi or for importing into other Pulumi stacks if necessary.

- A `kubernetes.Provider` is initialized with the `kubeConfig` provided by the newly created DigitalOcean Kubernetes cluster; this provider is used to interact with our Kubernetes cluster.

- We deploy the Helm chart called `helm-mongodb-operator` to the Kubernetes cluster. The `values` property is an object that can hold custom value overrides for the Helm chart.

- Finally, we export a URL that you can use to access the MongoDB dashboard once the Helm chart is fully deployed and operational.

Keep in mind that you will need to first set up your Pulumi environment, the Digital Ocean Provider, and have `kubectl` installed and configured to use this Pulumi program correctly. The MongoDB operator chart you wish to install also needs to be defined correctly in your Helm repository, as the code above assumes you have this chart available in the Helm repository specified. If the chart is in a different repository, you will need to specify the `repo` option in the `kubernetes.helm.v3.Chart` resource.