Deploy the python-app helm chart on Linode Kubernetes Engine

Question

Pulumi · Accepted Answer

To deploy a Helm chart to the Linode Kubernetes Engine using Pulumi, we will be working with the `@pulumi/kubernetes` library which allows us to interact with Kubernetes resources including Helm charts. Helm charts are a way to package Kubernetes applications that you can deploy as a single unit, and 'python-app' in this context would be a Helm chart for a Python application.

Here are the steps we'll follow to deploy the 'python-app' Helm chart:

1. Set up a new Pulumi project and install necessary dependencies.
2. Configure our Linode provider if necessary.
3. Write a TypeScript Pulumi program that instantiates a Kubernetes cluster on the Linode Kubernetes Engine.
4. Deploy the 'python-app' Helm chart to the newly created Linode Kubernetes cluster.

I'll now provide a detailed TypeScript program to accomplish this task. Before running this code, ensure you have Pulumi installed and configured with Linode access credentials.

```typescript
import * as kubernetes from "@pulumi/kubernetes";
import * as linode from "@pulumi/linode";

// Create a new Linode Kubernetes Engine (LKE) cluster
const cluster = new linode.LkeCluster("my-python-app-cluster", {
    k8sVersion: "1.20", // specify the version of Kubernetes
    region: "us-central", // choose the appropriate region
    nodePools: {
        nodes: [
            {
                // Define the type and number of Linode instances for your node pool
                type: "g6-standard-2",
                count: 3,
            },
        ],
    },
});

// Once the cluster is created, we can configure the Kubernetes provider to use the kubeconfig from the newly created LKE cluster.
const k8sProvider = new kubernetes.Provider("k8s-provider", {
    kubeconfig: cluster.kubeconfig.apply(JSON.stringify),
});

// Now, we will use the Helm chart resource to deploy our Python application using a Helm chart.
// We assume that the 'python-app' chart is available in a Helm chart repository.

// Deploy 'python-app' Helm chart
const pythonAppChart = new kubernetes.helm.v3.Chart("python-app", {
    chart: "python-app",
    version: "1.0.0", // replace with the specific version you want to deploy
    fetchOpts: {
        repo: "http://example.com/helm-charts", // the URL to your Helm chart repository
    },
}, { provider: k8sProvider }); // Use the Kubernetes provider configured with the LKE cluster

// Export the Kubeconfig and the public service endpoint for the Python app
export const kubeconfig = cluster.kubeconfig;
export const pythonAppEndpoint = pythonAppChart.getResourceProperty("v1/Service", "python-app-service", "status").apply(status => status.loadBalancer.ingress[0]);

```

### Explanation:

- We import the `@pulumi/kubernetes` and `@pulumi/linode` SDKs to interact with Kubernetes resources and manage the Linode Kubernetes Engine cluster.
- We create an LKE cluster with a single node pool consisting of three Linode virtual machine instances.
- We define a `kubernetes.Provider` which uses the kubeconfig provided by the Linode cluster so Pulumi can communicate with our Kubernetes cluster.
- We then create a Helm chart resource, specifying the name and version of the chart, as well as the location of the Helm chart repository.
- We've also provided a sample HTTP repository URL `http://example.com/helm-charts`; you'll replace this with the actual URL to your Helm repository where the 'python-app' chart is hosted.
- We specify a version for the Helm chart. It's important to replace `"1.0.0"` with the actual chart version you'd like to deploy.
- We use the LKE kubeconfig when setting up our Kubernetes provider, ensuring that Pulumi targets our newly created cluster.
- Finally, we export the `kubeconfig` to interact with our cluster using `kubectl`, and the public service endpoint to access the deployed Python application.

### Next Steps:

- Replace the `chart`, `version`, and `repo` fields with the correct values for your Python application's Helm chart.
- Make sure you have access permissions to the provided Helm chart repository.
- If you're running this code outside of Linode, ensure you have configured your local environment with the necessary Linode credentials.
- After setting up the Pulumi project, you can deploy the code by running `pulumi up` from the command line.

Remember that this demonstrates how to deploy a Helm chart on an LKE cluster using Pulumi and assumes that the necessary Helm chart for your Python application exists in a chart repository. If any additional Helm configuration values are required, they can be supplied through the `values` field on the `kubernetes.helm.v3.Chart` resource.