How do I integrate HTTP Addons with KEDA for event-driven autoscaling?

In this guide, we will learn how to integrate HTTP Addons with KEDA (Kubernetes Event-Driven Autoscaling) to enable event-driven autoscaling in a Kubernetes cluster using Pulumi. KEDA allows Kubernetes to scale applications based on external events such as messages in a queue, HTTP requests, or other custom metrics.

Key Points:

We will deploy an HTTP server as a deployment in Kubernetes.
We will configure KEDA to scale the deployment based on the number of HTTP requests.
We will use Pulumi to manage the infrastructure as code.

Detailed Explanation:

HTTP Server Deployment: We will create a Kubernetes deployment for an HTTP server.
KEDA ScaledObject: We will configure KEDA to monitor the HTTP server and scale it based on the number of incoming requests.
KEDA HTTP Addon: We will use the KEDA HTTP Addon to integrate HTTP scaling capabilities.

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

// Create a Kubernetes namespace for KEDA
const kedaNamespace = new k8s.core.v1.Namespace("keda-namespace", {
    metadata: {
        name: "keda",
    },
});

// Deploy KEDA to the Kubernetes cluster
const kedaOperator = new k8s.helm.v3.Chart("keda", {
    chart: "keda",
    version: "2.4.0",
    fetchOpts: {
        repo: "https://kedacore.github.io/charts",
    },
    namespace: kedaNamespace.metadata.name,
});

// Create a deployment for the HTTP server
const httpServerDeployment = new k8s.apps.v1.Deployment("http-server", {
    metadata: {
        name: "http-server",
    },
    spec: {
        replicas: 1,
        selector: {
            matchLabels: {
                app: "http-server",
            },
        },
        template: {
            metadata: {
                labels: {
                    app: "http-server",
                },
            },
            spec: {
                containers: [
                    {
                        name: "http-server",
                        image: "hashicorp/http-echo",
                        args: ["-text=hello"],
                        ports: [
                            {
                                containerPort: 5678,
                            },
                        ],
                    },
                ],
            },
        },
    },
});

// Expose the HTTP server via a Kubernetes service
const httpServerService = new k8s.core.v1.Service("http-server-service", {
    metadata: {
        name: "http-server-service",
    },
    spec: {
        selector: {
            app: "http-server",
        },
        ports: [
            {
                protocol: "TCP",
                port: 80,
                targetPort: 5678,
            },
        ],
    },
});

// Create a KEDA ScaledObject to scale the HTTP server based on HTTP requests
const httpScaledObject = new k8s.apiextensions.CustomResource("http-scaledobject", {
    apiVersion: "keda.sh/v1alpha1",
    kind: "ScaledObject",
    metadata: {
        name: "http-scaledobject",
        namespace: kedaNamespace.metadata.name,
    },
    spec: {
        scaleTargetRef: {
            name: httpServerDeployment.metadata.name,
        },
        triggers: [
            {
                type: "http",
                metadata: {
                    targetPendingRequests: "100",
                    host: `http://${httpServerService.metadata.name}`,
                },
            },
        ],
    },
});

// Export the HTTP server URL
export const httpUrl = pulumi.interpolate`http://${httpServerService.metadata.name}`;

Conclusion

In this guide, we integrated HTTP Addons with KEDA to enable event-driven autoscaling in a Kubernetes cluster. We deployed an HTTP server, exposed it via a Kubernetes service, and configured a KEDA ScaledObject to scale the deployment based on the number of HTTP requests. This setup allows your application to scale dynamically in response to incoming HTTP traffic.

Deploy this code

Want to deploy this code? Sign up for a free Pulumi account to deploy in a few clicks.

New to Pulumi?

Want to deploy this code? Sign up with Pulumi to deploy in a few clicks.