Deploy the cert-manager-configs helm chart on Azure Kubernetes Service (AKS)

Question

Pulumi · Accepted Answer

In order to deploy the `cert-manager-configs` Helm chart on Azure Kubernetes Service (AKS), we'll need to run through several steps using Pulumi's TypeScript programming language.

1. **Create an AKS Cluster**: We'll start by defining an AKS cluster resource in Pulumi. This will provision the Kubernetes cluster where our applications and services will run.

2. **Install Cert-Manager**: After having the cluster ready, we'll use Pulumi's Helm chart resource to deploy Cert-Manager, which is a Kubernetes add-on to automate the management and issuance of TLS certificates from various issuing sources.

3. **Configure Networking** (if necessary): Cert-Manager typically requires access to DNS and HTTP resources to validate domain ownership and issue certificates. We might need to configure networking options like service annotations or ingress resources as needed, depending on your specific scenario.

Before proceeding, please make sure you have:

- Installed the Pulumi CLI.
- Configured your Azure credentials for use with Pulumi.
- Created a Pulumi stack and project.

The following program illustrates how to do this:

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as k8s from "@pulumi/kubernetes";
import * as aks from "@pulumi/azure-native/containerservice";
import * as resources from "@pulumi/azure-native/resources";

// Step 1: Create a new resource group for the AKS cluster if it doesn't exist
const resourceGroupName = new resources.ResourceGroup("myResourceGroup");

// Step 2: Create the AKS cluster
const cluster = new aks.ManagedCluster("myAKSCluster", {
    resourceGroupName: resourceGroupName.name,
    agentPoolProfiles: [{
        count: 2,
        vmSize: "Standard_DS2_v2",
        mode: "System",
    }],
    dnsPrefix: "myakscluster",
    // Enable RBAC for the cluster
    enableRbac: true,
});

// Export the Kubeconfig for the AKS cluster
export const kubeconfig = pulumi.all([cluster.name, resourceGroupName.name]).apply(([clusterName, rgName]) =>
    aks.listManagedClusterUserCredentials({
        resourceName: clusterName,
        resourceGroupName: rgName,
    }).then(creds => Buffer.from(creds.kubeconfigs[0].value, 'base64').toString())
);

// Step 3: Create a provider for the AKS cluster
const k8sProvider = new k8s.Provider("k8sprovider", {
    kubeconfig: kubeconfig,
});

// Step 4: Deploy cert-manager-configs Helm chart using Pulumi
const certManager = new k8s.helm.v3.Chart("cert-manager", {
    repo: "jetstack",
    chart: "cert-manager",
    version: "1.5.3", // Specify the version of cert-manager you wish to install
    // Include any custom values you need for the cert-manager Helm chart
    // Often these are things like ingress class, email for letsencrypt etc. 
    // For example: 
    values: {
        installCRDs: true,
    },
}, { provider: k8sProvider });

// Export the cert-manager Helm chart status
export const certManagerStatus = certManager.status;
```

### Breakdown of the Program:

1. The `resources.ResourceGroup` class creates a new Azure resource group, which will contain the AKS cluster. Resource groups help keep your Azure resources organized.

2. `aks.ManagedCluster` class is used to create the AKS cluster. This includes setting up the Kubernetes version, the size of the VMs for the nodes, the count of the nodes, enabling RBAC, and specifying the DNS prefix for the services to be hosted.

3. `pulumi.all` and `aks.listManagedClusterUserCredentials` are used together to fetch the credentials of the AKS cluster and convert them to Kubeconfig format, so you can interact with your cluster using `kubectl`.

4. `k8s.Provider` class configures the Kubernetes provider with the Kubeconfig of our cluster. It allows Pulumi to perform deployments on the AKS we've provisioned.

5. `k8s.helm.v3.Chart` class deploys the `cert-manager` helm chart onto the AKS cluster. The specified `values` field in the chart should contain configurations specific to Cert-Manager, and `installCRDs` is set to true to ensure that Cert-Manager's custom resource definitions are created during installation.

6. Finally, we export `certManager.status` which will give us info about the deployment status of the helm chart.

By running this Pulumi program, you will create an AKS cluster and deploy Cert-Manager on it. Please review the Helm chart values you need and apply them where needed. The `kubeconfig` is crucially important as it is needed to manage the Kubernetes cluster and should be handled securely.