🛡️ Keycloak + Spring Boot Tutorial

A simple and elegant tutorial to learn how to integrate Keycloak (Open Source Identity and Access Management) with a Spring Boot application using Docker.

📚 Overview

This project demonstrates:

• Setting up a Keycloak server using Docker
• Creating and configuring a Realm, Users, and Roles
• Integrating Spring Boot with Keycloak
• Implementing a custom JWT Converter to prefix Keycloak roles with ROLE_ for Spring Security compatibility

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⚙️ Stack

• 🐳 Docker
• ☕ Spring Boot
• 🛡️ Keycloak
• 🔐 Spring Security
• 💬 JWT (JSON Web Token)

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🚀 Getting Started

1. Start Keycloak with Docker

docker run -p 127.0.0.1:8080:8080 -e KC_BOOTSTRAP_ADMIN_USERNAME=admin -e KC_BOOTSTRAP_ADMIN_PASSWORD=admin quay.io/keycloak/keycloak:26.3.1 start-dev