How Do I Scale Keycloak for High Availability on Kubernetes?

Introduction

Scaling Keycloak for high availability on Kubernetes is crucial for maintaining a reliable and fault-tolerant authentication system. This guide provides a step-by-step approach to deploying Keycloak on Kubernetes using Pulumi, ensuring that it can handle multiple requests and maintain uptime even if some instances fail. The purpose of this guide is to help you set up Keycloak with high availability by utilizing Kubernetes capabilities.

Deployment Process

To achieve high availability, Keycloak will be deployed using a Kubernetes Deployment with multiple replicas and exposed via a Kubernetes Service of type LoadBalancer. Here’s how to set it up:

1. Create a Kubernetes Namespace: Start by creating a dedicated namespace for Keycloak to isolate its resources.

2. Define a Deployment: Set up a Kubernetes Deployment for Keycloak with multiple replicas. This ensures that if one instance fails, others can continue to serve requests.

3. Configure the Pods: Each Keycloak pod should be configured with necessary environment variables for database setup and admin credentials.

4. Set Up a LoadBalancer Service: Use a Kubernetes Service of type LoadBalancer to expose Keycloak externally. This distributes incoming traffic across the Keycloak replicas.

The following TypeScript code demonstrates the setup:

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

const keycloakNs = new kubernetes.core.v1.Namespace("keycloak_ns", {metadata: {
    name: "keycloak",
}});
const keycloak = new kubernetes.apps.v1.Deployment("keycloak", {
    metadata: {
        namespace: keycloakNs.metadata.apply(metadata => metadata.name),
        name: "keycloak",
    },
    spec: {
        replicas: 3,
        selector: {
            matchLabels: {
                app: "keycloak",
            },
        },
        template: {
            metadata: {
                labels: {
                    app: "keycloak",
                },
            },
            spec: {
                containers: [{
                    name: "keycloak",
                    image: "jboss/keycloak:latest",
                    ports: [{
                        containerPort: 8080,
                    }],
                    env: [
                        {
                            name: "DB_VENDOR",
                            value: "H2",
                        },
                        {
                            name: "KEYCLOAK_USER",
                            value: "admin",
                        },
                        {
                            name: "KEYCLOAK_PASSWORD",
                            value: "admin",
                        },
                    ],
                }],
            },
        },
    },
});
const keycloakService = new kubernetes.core.v1.Service("keycloak", {
    metadata: {
        namespace: keycloakNs.metadata.apply(metadata => metadata.name),
        name: "keycloak",
    },
    spec: {
        selector: {
            app: "keycloak",
        },
        type: kubernetes.core.v1.ServiceSpecType.LoadBalancer,
        ports: [{
            port: 80,
            targetPort: 8080,
        }],
    },
});
export const namespace = keycloakNs.metadata.apply(metadata => metadata.name);
export const keycloakServiceName = keycloakService.metadata.apply(metadata => metadata.name);

Key Points

• Namespace Isolation: A dedicated namespace keycloak is used to organize resources.
• High Availability: The Deployment is configured with 3 replicas to ensure continuous availability.
• Environment Configuration: Pods are set up with environment variables for database and admin credentials.
• Traffic Management: A LoadBalancer Service is used to handle external traffic efficiently.

Conclusion

By following this guide, you can effectively scale Keycloak on Kubernetes to achieve high availability. This setup ensures that your authentication system remains robust and capable of handling failures without downtime. High availability is critical for maintaining user trust and ensuring seamless access to services. Implementing these steps will help you maintain a reliable and efficient Keycloak deployment on Kubernetes.