Deploy the heartbeat helm chart on Azure Kubernetes Service (AKS)

Question

Pulumi · Accepted Answer

Deploying the Heartbeat Helm chart on Azure Kubernetes Service (AKS) involves several key steps. Since you're a novice looking to learn, I’ll break these down for you.

1. **Creating an AKS Cluster**: This is the environment where your Kubernetes-based applications will run. AKS simplifies the process of deploying a managed Kubernetes cluster in Azure as it handles much of the complexity and overhead for you.

2. **Configuring Kubeconfig**: For Helm to interact with your AKS cluster, it needs to know how to communicate with it. This is done through a kubeconfig file which stores configuration information about clusters, users, namespaces, and authentication mechanisms.

3. **Installing Helm**: Helm is a package manager for Kubernetes that allows you to define, install, and upgrade even the most complex Kubernetes applications in a more manageable way using charts. In this case, we're looking to deploy the Heartbeat Helm chart.

4. **Deploying the Chart**: Using Pulumi's integration with Helm, you can deploy the Heartbeat chart to your AKS cluster.

Now, let's look at the Pulumi TypeScript code for this process:

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as k8s from "@pulumi/kubernetes";
import * as azure from "@pulumi/azure";
import * as azuread from "@pulumi/azuread";
import * as random from "@pulumi/random";

// Set up an Azure Resource Group
const resourceGroup = new azure.core.ResourceGroup("aksResourceGroup");

// Create an Azure AD application for AKS
const app = new azuread.Application("aksApp");

// Create a Service Principal for the AD application
const servicePrincipal = new azuread.ServicePrincipal("aksSp", {
    applicationId: app.applicationId,
});

// Create a Service Principal Password
const password = new random.RandomPassword("password", {
    length: 20,
    special: true,
});

const servicePrincipalPassword = new azuread.ServicePrincipalPassword("aksSpPassword", {
    servicePrincipalId: servicePrincipal.id,
    value: password.result,
    endDate: "2099-01-01T00:00:00Z",
});

// Create the AKS cluster
const cluster = new azure.containerservice.KubernetesCluster("aksCluster", {
    resourceGroupName: resourceGroup.name,
    defaultNodePool: {
        name: "aksagentpool",
        nodeCount: 2,
        vmSize: "Standard_DS2_v2",
    },
    dnsPrefix: `${pulumi.getStack()}-kube`,
    servicePrincipal: {
        clientId: app.applicationId,
        clientSecret: servicePrincipalPassword.value,
    },
    kubernetesVersion: "1.18.14",
});

// Export the cluster's kubeconfig
export const kubeconfig = cluster.kubeConfigRaw;

// Create a Kubernetes provider instance that uses our cluster from above.
const provider = new k8s.Provider("provider", {
    kubeconfig: cluster.kubeConfigRaw,
});

// Deploy the Heartbeat Helm chart into the AKS cluster
const chart = new k8s.helm.v3.Chart("heartbeat", {
    chart: "elastic/heartbeat",
    version: "7.10.0",
    fetchOpts: {
        repo: "https://helm.elastic.co",
    },
}, { provider });

// Export the Chart name
export const chartName = chart.name;
```

### Explanation
- We import the necessary modules for Pulumi, Kubernetes, Azure, Azure AD, and Random Password creation.
- An Azure Resource Group is set up to organize the resources.
- An Azure AD application and corresponding service principal are created for the AKS cluster to interact with other Azure services securely.
- We generate a strong random password for the service principal.
- The AKS cluster resource is created with a default node pool configuration suitable for quick starts.
- `kubeconfig` is exported so that the AKS cluster can be managed using `kubectl` if desired.
- A Pulumi Kubernetes provider instance is configured to interact with our AKS cluster.
- Using the `k8s.helm.v3.Chart` resource, we install the "elastic/heartbeat" Helm chart into our AKS cluster, specifying the version and Helm repository.

This program, once executed with Pulumi, will:

1. Provision the necessary Azure resources including the AKS cluster.
2. Configure access credentials to communicate with the cluster.
3. Deploy the specified version of the Heartbeat Helm chart onto the AKS cluster.

Make sure to adjust the version of Heartbeat you need and note that Pulumi automatically handles the dependency between resources, so the Helm chart will only be deployed once the AKS cluster is ready.