Deploy the deploy-flask helm chart on Linode Kubernetes Engine

Question

Pulumi · Accepted Answer

To deploy a Flask application using a Helm chart on Linode Kubernetes Engine (LKE) with Pulumi, you will perform several steps:

Set up your Linode Kubernetes cluster resource.
Create a Helm Release for your Flask application.

In this scenario, we'll use Pulumi's Kubernetes provider to manage the cluster and Helm deployments. The Helm chart used for a Flask application could be custom or sourced from a Helm repository. Here, I am assuming that there is a Helm chart named deploy-flask available either in a public repository or a repository that you have added to your Helm configuration.

If you don't have a specific Helm chart for Flask, you can find one or create it. Typically, a Flask Helm chart will include definitions for Kubernetes services (to expose your Flask app), deployments (to run your Flask app), and any other necessary Kubernetes resources.

First, ensure you have the following prerequisites:

Linode account and an access token for the Linode API
Linode CLI installed and configured
Pulumi CLI installed
A Kubernetes cluster set up in Linode (You can use Pulumi to set up one as well, but that's beyond the scope of this reply)

The following program demonstrates how to deploy a Flask application using Helm in a Linode Kubernetes cluster using Pulumi with TypeScript. Make sure to replace 'your-repo' with the repository name where your Flask Helm chart is located and '<your-chart>' with the actual Helm chart name for Flask. Also, update the values parameter with the appropriate configuration you desire for your Flask application.

import * as k8s from "@pulumi/kubernetes";

// Create a Kubernetes provider instance that uses our Linode Kubernetes cluster.
const linodeK8sProvider = new k8s.Provider("linodeK8sProvider", {
    kubeconfig: "<your-kubeconfig>", // Your kubeconfig from Linode
});

// Deploy the Flask app using the Helm chart.
const flaskAppRelease = new k8s.helm.v3.Release("flaskApp", {
    chart: "<your-chart>", // The name of the chart
    version: "<chart-version>", // The chart version, if necessary
    repositoryOpts: {
        repo: "https://your-repo.github.io/helm-charts", // The URL to your Helm chart repository
    },
    values: { // Custom values for your Flask Helm chart
        // These values will be different based on your Helm chart's configuration options
        image: {
            repository: "<your-flask-app-image>",
            tag: "latest",
        },
        service: {
            type: "LoadBalancer",
            port: 80,
        },
        // Any other configuration values that your chart accepts.
    },
}, { provider: linodeK8sProvider });

// Export any relevant resource properties.
export const flaskAppServiceUrl = flaskAppRelease.status.apply(status => status.resources[0].status.loadBalancer.ingress[0].hostname);

This Pulumi TypeScript program does the following:

Imports the necessary Kubernetes package from Pulumi.
Initializes a Kubernetes provider pointing to your Linode Kubernetes cluster (You will need to replace "<your-kubeconfig>" with your actual kubeconfig contents from Linode).
Creates a Helm release for the Flask application (You need to replace "<your-chart>" and "https://your-repo.github.io/helm-charts" with the name and repository URL of your Helm chart for Flask, respectively).
Sets up custom values for the Helm chart, such as the Docker image for the Flask app (Replace "<your-flask-app-image>" with the Docker image location of your Flask app).
Optionally exports the URL of the Flask application's service if it's exposed to the internet—this depends on your Helm chart's output specifications.

Please make sure to adjust placeholders and configuration options according to your specific Helm chart properties and the way you've set up your Linode Kubernetes Engine.

To run this Pulumi program, you'll need to create a new Pulumi project and use this code as the main application file (typically named index.ts). You can create a new Pulumi project by running pulumi new typescript in your terminal.

Note: This explanation assumes that you are already familiar with Kubernetes concepts, Helm, and Pulumi basics. If any of these concepts are new to you, I recommend reviewing the Pulumi Getting Started Guide, Kubernetes documentation, and Helm charts introduction to get up to speed.