Deploy the letsencrypt-setup helm chart on Oracle Kubernetes Engine (OKE)

Question

Pulumi · Accepted Answer

Deploying a Helm chart on a Kubernetes cluster like Oracle Kubernetes Engine (OKE) is a common task when managing cloud-native applications. Helm is a package manager for Kubernetes that allows you to define, install, and upgrade Kubernetes applications using charts, which are packages of pre-configured Kubernetes resources.

To deploy a Helm chart for setting up Let's Encrypt on OKE using Pulumi, we'll follow these steps:

1. **Set up the OKE Cluster**: Before deploying any applications, you'll need a running Kubernetes cluster. In this case, we're dealing with OKE, Oracle's managed Kubernetes service. Pulumi supports Oracle Cloud Infrastructure (OCI), and you can create an OKE cluster using Pulumi's OCI provider. You would likely have set this up separately.

2. **Install Cert-Manager**: Let's Encrypt certificates are commonly managed in a Kubernetes cluster using the cert-manager tool, which automates the management and issuance of TLS certificates. It's a prerequisite for any Helm chart that sets up Let's Encrypt, as the cert-manager will handle the certificates.

3. **Deploy the Let's Encrypt Setup Helm Chart**: You'll deploy the Helm chart that communicates with Let's Encrypt to issue and renew certificates as needed. Such a Helm chart is not officially provided by Let's Encrypt but can be created or obtained from the community as needed.

4. **Configure the Helm Release**: This includes setting any required values, such as domain names and email addresses, which are necessary for Let's Encrypt to issue certificates.

Below is a Pulumi program in TypeScript which assumes you have an existing OKE cluster and focuses on the steps 2 and 3, deploying cert-manager and a hypothetical `letsencrypt-setup` Helm chart on this cluster. I'm also including the import of `pulumi/oci` for creating resources in Oracle Cloud and `pulumi/kubernetes` for interacting with the Kubernetes cluster and Helm charts.

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

// Retrieve the kubeconfig for the existing OKE cluster.
// The specifics of this will depend on how you've set up your OCI cluster.
const kubeconfig = oci.containerengine.getClusterKubeconfig({
    // You should replace this with your actual cluster OCID
    clusterId: "your-oke-cluster-ocid",
});

// Create a new instance of the Kubernetes provider based on the retrieved kubeconfig
const provider = new k8s.Provider("oke-provider", {
    kubeconfig: kubeconfig,
});

// Install the cert-manager Helm chart into the cluster.
const certManagerChart = new k8s.helm.v3.Chart("cert-manager", {
    chart: "cert-manager",
    version: "v1.2.0",  // Replace with the version you want to install
    namespace: "cert-manager",
    fetchOpts:{
        repo: "https://charts.jetstack.io",
    },
}, { provider: provider });

// Deploy the letsencrypt-setup Helm chart
const letsEncryptSetupChart = new k8s.helm.v3.Chart("letsencrypt-setup", {
    // The chart would be sourced from the repository that hosts the letsencrypt-setup chart.
    // Replace `repoUrl` with the actual repository URL and `chartName` with the chart's name.
    chart: "letsencrypt-setup-chart-name",
    version: "version-of-the-chart",
    namespace: "letsencrypt-setup",
    // Values to configure the Chart. `email` and `domain` are placeholders
    // for actual configuration parameters required by the letsencrypt-setup Chart.
    values: {
        email: "your-email@example.com",
        domain: "yourdomain.com",
        // Additional chart values required for setup
    },
}, { provider: provider });

// Export any essential information, for example the Chart status or endpoints
export const certManagerStatus = certManagerChart.status;
export const letsEncryptSetupStatus = letsEncryptSetupChart.status;
```

Here's what each part of the code does:

- The `oci.containerengine.getClusterKubeconfig` function retrieves the kubeconfig of an OKE cluster which is used to configure the Kubernetes provider.
- The `k8s.Provider` resource represents the Kubernetes provider which is configured using the kubeconfig from the first step. This provider is responsible for deploying resources into the OKE cluster.
- The `k8s.helm.v3.Chart` resource represents a Helm chart in Pulumi. The first instance installs cert-manager in the cluster from the Jetstack Helm repository. The namespace and version are specified explicitly.
- The second `k8s.helm.v3.Chart` resource represents the deployment of the `letsencrypt-setup` Helm chart. In the `values` section, you configure the chart with necessary details. Replace the placeholders with actual values required by the Helm chart you are using.
- We export the statuses of the cert-manager and `letsencrypt-setup` Helm charts which can be viewed after deployment to confirm that everything is set up correctly.

Make sure to replace placeholders with your actual cluster ID, Helm chart metadata (name, repo URL, version), and any necessary values for the Helm chart's configuration.

To run the Pulumi program, you run `pulumi up` in the directory where your Pulumi program is saved after installing Pulumi CLI and setting up the OCI configuration. Pulumi will perform the necessary steps to deploy the Helm charts to your OKE cluster.

For the full implementation, you would need to properly handle the credentials and sensitive information, potentially using Pulumi configuration secrets or other secure storage methods. Additionally, you need to ensure that your OCI and Kubernetes provider configurations are properly set up according to your environment's requirements.