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

Question

Pulumi · Accepted Answer

To deploy a multicloud Helm chart on Azure Kubernetes Service (AKS), we will be using Pulumi with TypeScript. Pulumi allows us to define infrastructure as code using familiar programming languages. We will perform the following steps:

1. **Set Up AKS**: Provision an AKS cluster where the Helm chart will be deployed.
2. **Deploy the Helm Chart**: Use the Pulumi Kubernetes provider to deploy a Helm chart to the AKS cluster.

For the purposes of this deployment, we'll use the `kubernetes.helm.v3.Chart` resource from Pulumi to deploy our Helm chart onto the AKS cluster. The `Chart` resource allows us to deploy packaged applications into our Kubernetes cluster. This abstracts away the complexity behind applying Kubernetes manifests directly and provides an easy way to deploy and manage applications with Helm.

Below is a complete Pulumi program in TypeScript that provisions an AKS cluster and then deploys a Helm chart to that cluster. This example assumes you have already set up Azure credentials for use with Pulumi.

Firstly, ensure you have the Pulumi CLI installed and configured for Azure.

Now, let’s look at the code:

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

// Create a new resource group
const resourceGroup = new azure_native.resources.ResourceGroup('my-resource-group');

// Create an AKS cluster for our K8s cluster.
const aksCluster = new azure_native.containerservice.ManagedCluster('my-aks-cluster', {
    resourceGroupName: resourceGroup.name,
    kubernetesVersion: '1.18.14',
    agentPoolProfiles: [{
        count: 3,
        vmSize: 'Standard_DS2_v2',
        mode: 'System',
        name: 'agentpool',
    }],
    dnsPrefix: `${pulumi.getStack()}-kube`,
    enableRBAC: true,
    // Add required network profile fields.
});

// Export the AKS cluster kubeconfig.
export const kubeconfig = aksCluster.kubeConfig;

// Create a Kubernetes provider instance that uses our cluster from above.
const k8sProvider = new k8s.Provider('k8s-provider', {
    kubeconfig: aksCluster.kubeConfig,
});

const chart = new k8s.helm.v3.Chart('my-chart', {
    chart: 'my-multicloud-chart',
    // Assuming this chart is in your Helm repository
    fetchOpts: {
        repo: "http://myhelmrepo.azurecr.io/helm/v3/repo/",
    },
    // Specify the namespace, and any values you want to override from the 
    // default chart configuration.
    namespace: 'default',
    values: {
        // Add configuration options here
    },
}, { provider: k8sProvider });

// Expose any necessary ports or URLs as stack outputs by querying the k8s provider.
export const frontendService = chart.getResource('v1/Service', 'default', 'my-chart-frontend');
```

In the above code:
- We first create an Azure resource group named `my-resource-group` to organize all our Azure resources.
- Next, we provision an AKS cluster named `my-aks-cluster`. You can adjust the `kubernetesVersion` and `agentPoolProfiles` as needed for your specific requirements.
- We then output the `kubeconfig` of our AKS cluster, which we will need to manage and interact with our cluster using `kubectl`.
- Afterwards, we instantiate a Pulumi Kubernetes provider configured to use the AKS cluster's kubeconfig.
- Finally, we declare a `Chart` resource to deploy our Helm chart onto the AKS cluster. You would need to change `'my-multicloud-chart'` and the `repo` URL to match the Helm chart you wish to deploy. The `namespace` and `values` properties can be customized to specify the target namespace and set configuration options for the Helm chart, respectively.

Run the program using the Pulumi CLI. First, you'll need to save this code to an `index.ts` file, then perform the following steps:

- Open a terminal and navigate to your project directory.
- Run `pulumi up` to preview and deploy your changes.

Note: Be sure to check the contents and default values of the Helm chart before you deploy it, as you might need to adjust the `values` property of the `Chart` accordingly. The `kubeconfig` should be treated securely and not exposed unnecessarily.

After you’ve run `pulumi up`, Pulumi performs the deployment and provides you with the output, which includes the `kubeconfig` of the AKS cluster. With this `kubeconfig`, you can use `kubectl` to interact with your AKS cluster and verify that the Helm chart was deployed correctly.

Keep in mind that this is a basic example to get you started. In practice, you would want to fine-tune your AKS configurations and the Helm chart deployment to fit your specific needs. This may involve setting up more advanced networking, storage, and security configurations.