Deploy the sentence-collector helm chart on Azure Kubernetes Service (AKS)

Question

Pulumi · Accepted Answer

To deploy a Helm chart on an Azure Kubernetes Service (AKS) cluster using Pulumi, we need to perform a few steps:

1. Set up an AKS Cluster: This includes configuring the necessary Azure resources such as the AKS, node pools, and any required networking configurations.
2. Install the Helm chart: Once we have an AKS cluster, we can deploy applications to it using Helm charts.

In this program, we use the `azure-native` provider to create an AKS cluster and the `kubernetes` package to deploy the Helm chart. Before running this Pulumi program, ensure that you have the appropriate Azure credentials configured in your environment.

Here's what our Pulumi TypeScript program will look like:

1. Import the necessary Pulumi libraries.
2. Set up the AKS cluster.
3. Configure the Helm chart deployment for the `sentence-collector` application.
4. Export any necessary outputs, such as the Kubernetes configuration or endpoint.

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

// Create a resource group for the AKS cluster
const resourceGroup = new azure.core.ResourceGroup("aksResourceGroup");

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

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

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

// Create the Service Principal Password
const spPassword = new azuread.ServicePrincipalPassword("aksSpPassword", {
    servicePrincipalId: servicePrincipal.id,
    value: password.result,
    endDateRelative: "2400h",
});

// Create the AKS cluster itself
const cluster = new azure.containerservice.KubernetesCluster("aksCluster", {
    resourceGroupName: resourceGroup.name,
    defaultNodePool: {
        name: "akspool",
        nodeCount: 2,
        vmSize: "Standard_D2_v2",
    },
    dnsPrefix: "aksService",
    linuxProfile: {
        adminUsername: "adminuser",
        sshKey: {
            keyData: "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQD3b...hRNw== adminuser@mydomain.com",
        },
    },
    servicePrincipal: {
        clientId: app.applicationId,
        clientSecret: spPassword.value,
    },
});

// Export the Kubeconfig for the AKS cluster
export const kubeconfig = cluster.kubeconfig;

// Create a Kubernetes Provider instance using the generated Kubeconfig
const k8sProvider = new k8s.Provider("k8sProvider", {
    kubeconfig: kubeconfig,
});

// Create a Helm Chart resource for the "sentence-collector" deployment
const sentenceCollectorChart = new k8s.helm.v3.Chart("sentence-collector", {
    chart: "sentence-collector",
    // You may need to specify the repository where the "sentence-collector" Helm chart is located
    // For example, if the chart is on Helm Hub: repo: "https://charts.helm.sh/stable"
    // If 'sentence-collector' is not the real name, replace it with the correct one.
}, { provider: k8sProvider });

// Export the AKS Cluster name and Helm chart status
export const aksClusterName = cluster.name;
export const sentenceCollectorStatus = sentenceCollectorChart.status;

```

Here is an explanation of the Pulumi resources used in this program:

- **ResourceGroup**: A logical container into which Azure resources like web apps, databases, and storage accounts are deployed and managed.

- **Application, ServicePrincipal, ServicePrincipalPassword**: These Azure Active Directory (Azure AD) resources manage identity and access controls for the AKS cluster and provide a way for the Kubernetes Azure cloud provider to interact with Azure resources.

- **RandomPassword**: This creates a random password for the Service Principal, which improves security by avoiding hard-coded passwords.

- **KubernetesCluster**: This resource represents an AKS cluster where we will be deploying our application using Helm.

- **Provider**: The `k8s.Provider` is a Pulumi concept used to associate resources with a specific Kubernetes cluster using the cluster's kubeconfig. This is necessary for Pulumi to know which cluster to deploy resources to.

- **helm.v3.Chart**: The Helm chart resource is used to deploy the Sentence Collector application. You would need to provide the exact chart name and optionally the repository.

To deploy your application, you would run `pulumi up` from your terminal after saving this code into a Pulumi TypeScript project. Pulumi will communicate with Azure to set up the resources and configure them as defined in this program.

Make sure you review and update the details like the region, the node vm size, the SSH keys, the Helm chart name, and any other resource properties as needed for your use case.