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Implementing Secure Authentication with Keycloak

June 23, 2022

Many web-based applications implement authentication mechanisms to ensure security. However, securing these vulnerabilities from the ground up is a complicated task.

Due to these reasons, we tend to turn to external third-party services. One such service is Keycloak. KeyCloak is an open-source identity and access management service.

It aims to make it easier to handle security services in modern application infrastructure. Keycloak handles multiple authentication services such as login forms and storing user data.


This tutorial will help the reader understand how to set up a Keycloak server to secure React frontend applications.


To follow along, you need:

KeyCloak features

  • Single sign-on and sign-out mechanisms.
  • Support for OIDC e.g OpenID Connect and SAML 2.0.
  • Support for social media login channels.
  • User account management via both the web console and REST API.
  • Provision of Admin Console, Account Management Console, and Client Adapters.

KeyCloak set up and configurations

We will begin the setup by pulling the KeyCloak docker image from Docker Hub. On your terminal, confirm that Docker is installed by running the command:

docker version

If Docker is not installed on your system, head over and complete the setup guide for Linux, Windows, or macOS.

Next, pull the KeyCloak image from Docker Hub with the command:

docker pull jboss/keycloak

To successfully create a KeyCloak instance, we need to:

  • Expose a server port. In our case, we will use port 8080.
  • Specify a database that the Keycloak server will use. In this tutorial, we will go with the embedded H2 database.
  • Create admin credentials with a username and password.

Finally, begin the setup by running the command:

docker run -p 8080:8080 -e KEYCLOAK_PASSWORD=admin123 -e KEYCLOAK_USER=admin -e DB_VENDOR=H2 jboss/keycloak

Here, we pass along the KEYCLOAK_USER and KEYCLOAK_PASSWORD as environment variables.

Once our container fires up, navigate to your browser on http://localhost:8080/auth/admin and log in with the credentials we created earlier. On this page you should see something like:

Keycloak sign

Understanding key concepts

We need to briefly understand Keycloak terms and concepts as an authentication solution for web applications and RESTful services.

  • Realms: A realm creates the domain where we define all entities. In our setup so far, we have a master realm.
  • Roles: Roles guarantee authorization by levels to protect resources in the system. E.g an admin, a manager, staff, etc.
  • Users: Users are the entities within our Keyloak that access the system depending on their roles.
  • Identity Providers include any third party that we integrate E.g Facebook, Google, and OpenID Connect/SAML 2.0.

Creating Realm

Currently, we are at the master realm which is the root. The master realm is the recommended sandbox environment for admin tasks for creating other realms.

To create a new realm for our applications, use the left sidebar of the admin console. Under the dropdown option, click the Add realm button to add a new realm.

Add Realm

To create a realm, we need to specify a name. I’ll use the name myRealmDemo.

Within our newly created myRealmDemo, we will create a test user instance. On the left panel under the manage section, click Add User and provide a username and a password under the Credentials tab.

Add user

The initial password that’s created is temporary. Make sure to reset it before accessing the account management panel.

We can confirm our new user by navigating to http://localhost:8080/auth/realms/myRealmDemo/account.


For user details, add First name, Last name, and Email fields.

To complete our configuration on the Keycloak server, we need to add a client that will initiate login for any web service. Go back to the Clients tab under the admin console and click the Create button.

Add client

Provide a name as your Client ID and Root URL as http://localhost:3000 where our React client will run.

One last thing we need is the Keycloak JSON that we will pass along to the client when initiating requests. On the Installation tab, select Keycloak OIDC JSON as the data format. Keep it safe since we will reuse it in the next section!

installation tab

Set up React Frontend

To bootstrap our client app, we will use the Vite CLI build tool. To create a boilerplate React template with Vite, type the command:

yarn create vite react-keycloak-app --template react

Next, navigate into the react-keycloak-app folder and install all the dependencies:

cd react-keycloak-app && npm i

Other dependencies that our application needs include react-router-dom, keycloak-js, and tailwindcss. Let’s install the dependencies with the command:

npm i react-router-dom keycloak-js

Lastly, add TailwindCSS as a development dependency.

npm install -D tailwindcss postcss autoprefixer
npx tailwindcss init -p
content: [
@tailwind base;
@tailwind components;
@tailwind utilities;

Our app simply allows the client to navigate between public and protected routes. We have the following components:

  • App component is the root component.
  • NavBar component: For links and navigation.
  • Home component: This is a public route.
  • Resources component: To access this route, the client will have to be authenticated from our Keycloak server.
  • A Footer component with basic links and subscribe form.

App component

Inside our App.jsx file, add the code below. We will be creating these components in a moment.

import {BrowserRouter, Route, Routes} from 'react-router-dom';

// components
import NavBar from './components/NavBar';
import Footer from './components/Footer';
import Home from './components/Home';

import Resources from './components/Resources';

export default function App() {
  return (

      <Route path='/' element={<Home/>}/>
      <Route path='/resource' 


Our NavBar component will have the basic links for routes and a brand name as KeyCloak App. Add a folder for components named components.

Inside this folder, create NavBar.jsx file. We need to first import Link from the react-router package to handle navigation.

import {Link} from 'react-router-dom'

The nav links for our app:

export default function NavBar() {
  return (
    <div className='flex justify-around items-center py-5 bg-[#234] text-white'>
      <h1 className='font-semibold font-2xl'>KeyCloak App</h1>
      <ul className='flex'>

        <li className='mx-1'>
          <Link to='/'>Home</Link>
        <li className='mx-1'>
          <Link to='/resource'>Login</Link>
        <li className='mx-1'>
          <Link to ='/resource'>Resource</Link>

Home component

Within our components folder, add a new file and name it Home.jsx. The JSX for the file is:

export default function Home() {
  return (
    <div className='my-[12rem] text-center'>
      <p className='text-2xl font-bold'>Keycloak Landing Page. You are at Home &trade;</p>

Resources component

Add a new file under components folder as Resources.jsx. This component is stateful. Therefore, let’s import our keycloak package, useState, and useEffect as:

import { useState, useEffect } from 'react';
import Keycloak from 'keycloak-js';

Inside the Resources component, add the methods to check for keycloak instance and authentication. Using the useState hook:

export default function Resources(){
  const [keycloak, setKeycloak] = useState(null)
  const [authenticated, setAuthenticated] = useState(false)

To track the render cycle, use the useEffect hook so that when the component is mounted onto the DOM, we can invoke the Keycloak instance. The path needs to point to the keycloak.json path that we downloaded earlier.

    const keycloak = Keycloak('/keycloak.json');
    keycloak.init({ onLoad: 'login-required' }).then(authenticated => {
  }, [])

Lastly, we need to check that the user is authenticated with two states:

  • If keycloak exists (Keycloak returns an object) and the user is authenticated, we render a text and a random image.
  • If not, we return the “Unable to initiate auth!” message.
  if (keycloak) {
    if (authenticated) return (
      {/* JSX returns an image and text as protected **resources** */}
      <div className='my-12 grid place-items-center'>
        <p> You are logged in.</p>
          <img src="https://random.imagecdn.app/500/250"/> 
    else return (<div className='my-12'>Unable to initiate auth!</div>)

      <div className='my-12'>Keycloak initializing in a moment...</div>

Finally, our client code has a footer with social links and a subscribe button. Check the code below:

export default function Footer() {
  return (
    <div className='py-7 bg-[#1b252d] text-white grid grid-cols-1 place-items-center w-full'>
      <div className="shadow-lg">
          <div className='mb-4 text-white'>
            <p className='font-semibold'>Subscribe to Newsletter</p>
            <p>Get emails from me about web development, tech, and early access to new articles</p>
          <div className='relative'>
          <input placeholder='tim@apple.com' className='p-3 text-[#4b586e] rounded-tl-full rounded-bl-full outline-none'/>
          <button className='p-3 bg-[#4b586e] text-white rounded-tr-full rounded-br-full outline-none hover:bg-[#1b252e]'>
        <div className='mt-4'>
        <ul className='flex'>
          <li className='px-4'>Facebook</li>
          <li className='px-4'>Instagram</li>
          <li className='px-4'>Twitter</li>

Final demo

If we run the command npm run dev on our terminal. Our dev server fires up on localhost:3000. The final version of the app should look like this:

The home page as a public route:

App landing page

The protected route needs authentication with Keycloak:

resource component

You can download the project source code from this GitHub repo.


Digital technology has offered vast alternatives to implementing authentication services. From a user’s perspective, developers need multiple ways to verify identities and role management in accessing key systems and resources.

Therefore, having this set of tools in an open-source framework such as Keycloak is very convenient. This is what makes Keycloak a success in every way. Happy hacking!

Further reading

Peer Review Contributions by: Wanja Mike