Deploy the postgresql-backup helm chart on Azure Kubernetes Service (AKS)

Question

Pulumi · Accepted Answer

To deploy the `postgresql-backup` Helm chart on Azure Kubernetes Service (AKS), we'll go through the following steps:

1. **Provision an AKS cluster**: We need an AKS cluster where our `postgresql-backup` Helm chart will be deployed. We can create this cluster using Pulumi's AKS support.

2. **Install Helm**: Helm is a package manager for Kubernetes. It allows us to define, install, and upgrade complex Kubernetes applications. We will use the Helm support in Pulumi to deploy our chart to the AKS cluster.

3. **Deploy the Helm Chart**: Once we have Helm set up and the AKS cluster ready, we'll deploy the `postgresql-backup` chart.

Below is a TypeScript program that does this. We're using Pulumi's Azure Native provider for creating the AKS cluster and the Kubernetes provider for the Helm chart deployment. To run this code, you will need Node.js, Pulumi CLI, and an active Azure subscription properly configured on your environment.

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as azure_native from "@pulumi/azure-native";
import * as k8s from "@pulumi/kubernetes";
import * as azuread from "@pulumi/azuread";

// Step 1: Create an AKS cluster
const resourceGroupName = new azure_native.resources.ResourceGroup("resourceGroup", {
    resourceGroupName: "myResourceGroup",
    location: "East US", // Choose the appropriate Azure region where you want to deploy your AKS cluster
});

const adApp = new azuread.Application("adApp", {
    displayName: "adApp",
});

const adSp = new azuread.ServicePrincipal("adSp", {
    applicationId: adApp.applicationId,
});

const adSpPassword = new azuread.ServicePrincipalPassword("adSpPassword", {
    servicePrincipalId: adSp.id,
    endDate: "2099-01-01T00:00:00Z",
});

const k8sCluster = new azure_native.containerservice.ManagedCluster("k8sCluster", {
    resourceGroupName: resourceGroupName.name,
    agentPoolProfiles: [{
        count: 1,
        vmSize: "Standard_DS2_v2", // Adjust VM size according to your requirements or budget
        mode: "System",
        name: "agentpool",
        osType: "Linux",
    }],
    dnsPrefix: pulumi.interpolate`${resourceGroupName.name}-kube`,
    servicePrincipalProfile: {
        clientId: adApp.applicationId,
        secret: adSpPassword.value,
    },
}, {dependsOn: [adApp, adSp, adSpPassword]});

const creds = pulumi.all([resourceGroupName.name, k8sCluster.name]).apply(([resourceGroupName, clusterName]) =>
    azure_native.containerservice.listManagedClusterUserCredentials({
        resourceGroupName: resourceGroupName,
        resourceName: clusterName,
    })
);

const kubeconfig = creds.apply(creds => Buffer.from(creds.kubeconfigs[0].value, "base64").toString());

// Step 2: Set up the provider for deploying Helm chart
const k8sProvider = new k8s.Provider("k8sProvider", {
    kubeconfig: kubeconfig,
});

// Step 3: Deploy the Helm chart for postgresql-backup to the AKS cluster
const postgresqlBackupChart = new k8s.helm.v3.Chart("postgresql-backup", {
    chart: "postgresql-backup",
    version: "1.2.3", // Specify the version of the chart you want to deploy
    fetchOpts:{
        repo: "http://charts.example.com/", // Specify the Helm chart repository URL here
    },
}, { provider: k8sProvider });

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

In the above program:

- We first create a new resource group where our AKS cluster will reside.
- Next, we create an Active Directory application, a service principal, and a service principal secret required by AKS for authentication with Azure's APIs.
- We then define and create an AKS cluster with one node for simplicity. You can increase the number of nodes, change the VM size, and adjust other parameters as necessary.
- We retrieve the credentials for the created AKS cluster.
- Using the obtained credentials, we set up a Pulumi Kubernetes provider that allows us to interact with our AKS cluster.
- Finally, we define a Helm chart resource using the `@pulumi/kubernetes` module, specifying the name of the chart and its version.

Before executing this Pulumi program, make sure you have the required permissions and the helm chart `postgresql-backup` is available in the specified repository. You would run this Pulumi program using the standard Pulumi CLI commands `pulumi up` to create the resources and `pulumi destroy` when you need to delete them.

Remember to replace placeholders with actual values such as the `repo` field for the Helm chart repository. The `version` field should match the version of `postgresql-backup` that you intend to deploy.

Lastly, we export the kubeconfig, which can be used to access the Kubernetes cluster with `kubectl` or other Kubernetes management tools.

This program should be placed in a Pulumi project and you'll need to have Pulumi stack initialized and configured to use your Azure credentials. If you're missing any dependencies or have any issues running this code, please ensure that you've followed the installation and setup guides for Pulumi and that your Azure account is properly configured.