Deploy the python-api-postgres helm chart on Azure Kubernetes Service (AKS)

Question

Pulumi · Accepted Answer

To deploy the `python-api-postgres` Helm chart on an Azure Kubernetes Service (AKS) cluster using Pulumi, we must perform the following steps:

1. **Create an AKS cluster**: Provision an AKS cluster in Azure using Pulumi's Azure Native provider.
2. **Deploy the Helm chart**: Use Pulumi's Kubernetes provider to deploy the `python-api-postgres` chart on the AKS cluster.

Below is a Pulumi program written in TypeScript that accomplishes these steps. First, it provisions an AKS cluster, then it installs the Helm chart. I'll walk you through the entire process, step by step.

### Detailed Explanation

#### Step 1: Set Up Pulumi and Import Packages

Before writing the Pulumi program, you need to have Pulumi CLI installed and be logged into the Pulumi service or an alternative backend. You also need to have the Azure CLI installed and be logged into your Azure account to enable Pulumi to create resources within your Azure subscription.

In this TypeScript program, we'll use `@pulumi/azure-native` to provision resources in Azure and `@pulumi/kubernetes` to interact with Kubernetes and deploy the Helm chart.

#### Step 2: Define the AKS Cluster

Using Pulumi's Azure Native provider, we define an AKS cluster by specifying the necessary configurations such as the node size, number of nodes, and location. For simplicity, we're going to use default settings for some properties like networking, but you can customize this as needed.

#### Step 3: Deploy the Helm Chart

For deploying the Helm chart, we make use of Pulumi's Kubernetes provider. We'll reference our AKS cluster's kubeconfig for authentication. The `kubernetes.helm.v3.Chart` class will help us deploy the `python-api-postgres` chart from the specified repository.

Now, let's move on to the actual code.

```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 azureNative from '@pulumi/azure-native';

// Step 1: Create an Azure Resource Group
const resourceGroup = new azureNative.resources.ResourceGroup("resourceGroup");

// Step 2: Create an AKS cluster
const managedCluster = new azureNative.containerservice.ManagedCluster("aksCluster", {
    resourceGroupName: resourceGroup.name,
    agentPoolProfiles: [{
        count: 1,
        maxPods: 110,
        mode: "System",
        name: "agentpool",
        osDiskSizeGB: 30,
        osType: "Linux",
        vmSize: "Standard_DS2_v2",
    }],
    dnsPrefix: "aksk8s",
    enableRBAC: true,
    kubernetesVersion: "1.18.14",
    linuxProfile: {
        adminUsername: "testuser",
        ssh: {
            publicKeys: [{
                keyData: "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC...",
            }],
        },
    },
    nodeResourceGroup: `MC_azure-native-go_${resourceGroup.name}`,
    //...
});

// Export the kubeconfig for the AKS cluster
const creds = pulumi.all([managedCluster.name, resourceGroup.name]).apply(([clusterName, rgName]) =>
    azureNative.containerservice.listManagedClusterUserCredentials({
        resourceGroupName: rgName,
        resourceName: clusterName,
    }));

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

// Step 3: Deploy a Helm chart for the Python API and Postgres
const pythonApiPostgresChart = new k8s.helm.v3.Chart("python-api-postgres", {
    chart: "python-api-postgres",
    version: "1.0.0", // specify the chart version; change as needed
    fetchOpts: {
        // Specify the repository that contains the Helm chart
        repo: "http://helm-repo-url/charts",
    },
    values: {
        // Specify the values that the chart requires
        // These values will depend on the specific chart and your desired configuration
    },
}, { provider: new k8s.Provider("k8s-provider", { kubeconfig }) });

// Export the DNS name of the AKS cluster
export const aksClusterName = managedCluster.fqdn;
```

The output of this Pulumi program is the fully qualified domain name (FQDN) of the created AKS cluster. The program deploys both the Kubernetes resources and the Helm chart specified.

Keep in mind, the above example assumes you already have some sort of service principal or other Azure credentials set up to allow Pulumi to authenticate with Azure.

The program also presumes the existence of a Helm chart `python-api-postgres` and a corresponding values file for customization according to your needs. You'd replace `http://helm-repo-url/charts` with the actual URL to your Helm repository. The chart version is a placeholder and should be replaced with the actual version you want to deploy.

Make sure to replace the SSH public key with your actual SSH public key and customize any of the other properties as necessary for your scenario.