Keycloak Angular

Easy Keycloak setup for Angular applications.

About
Installation
Setup
AuthGuard
HttpClient Interceptor
Contributors
License

About

This library helps you to use keycloak-js in Angular applications providing the following features:

A Keycloak Service which wraps the keycloak-js methods to be used in Angular, giving extra functionalities to the original functions and adding new methods to make it easier to be consumed by Angular applications.
Generic AuthGuard implementation, so you can customize your own AuthGuard logic inheriting the authentication logic and the roles load.
A HttpClient interceptor that adds the authorization header to all HttpClient requests. It is also possible to disable this interceptor or exclude routes from having the authorization header.
This documentation also assists you to configure the keycloak in your Angular applications and with the client setup in the admin console of your keycloak installation.

Installation

Run the following command to install both Keycloak Angular and the official Keycloak client library:

npm install keycloak-angular keycloak-js

Note that keycloak-js is a peer dependency of Keycloak Angular. This change allows greater flexibility of choosing the right version of the Keycloak client version for your project.

Versions

Angular	keycloak-angular	keycloak-js	Support
10.x.x	8.x.x	10 - 11	Bugs / New Features
9.x.x	7.3.x	3.4.3 - 10 (excluding v7)	Bugs
8.x.x	7.2.x	3.4.3 - 9 (excluding v7)	Bugs

Choosing the right keycloak-js version

The Keycloak client documentation recommends to use the same version of your Keycloak installation.

A best practice is to load the JavaScript adapter directly from Keycloak Server as it will automatically be updated when you upgrade the server. If you copy the adapter to your web application instead, make sure you upgrade the adapter only after you have upgraded the server.

Setup

In order to make sure Keycloak is initialized when your application is bootstrapped you will have to add an APP_INITIALIZER provider to your AppModule. This provider will call the initializeKeycloak factory function shown below which will set up the Keycloak service so that it can be used in your application.

Use the code provided below as an example and implement it's functionality in your application. In this process ensure that the configuration you are providing matches that of your client as configured in Keycloak.

import { APP_INITIALIZER, NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { KeycloakAngularModule, KeycloakService } from 'keycloak-angular';
import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';

function initializeKeycloak(keycloak: KeycloakService) {
  return () =>
    keycloak.init({
      config: {
        url: 'http://localhost:8080/auth',
        realm: 'your-realm',
        clientId: 'your-client-id',
      },
      initOptions: {
        onLoad: 'check-sso',
        silentCheckSsoRedirectUri:
          window.location.origin + '/assets/silent-check-sso.html',
      },
    });
}

@NgModule({
  declarations: [AppComponent],
  imports: [AppRoutingModule, BrowserModule, KeycloakAngularModule],
  providers: [
    {
      provide: APP_INITIALIZER,
      useFactory: initializeKeycloak,
      multi: true,
      deps: [KeycloakService],
    },
  ],
  bootstrap: [AppComponent],
})
export class AppModule {}

In the example we have set up Keycloak to use a silent check-sso. With this feature enabled, your browser will not do a full redirect to the Keycloak server and back to your application, instead this action will be performed in a hidden iframe, so your application resources only need to be loaded and parsed once by the browser when the app is initialized and not again after the redirect back from Keycloak to your app.

To ensure that Keycloak can communicate through the iframe you will have to serve a static HTML asset from your application at the location provided in silentCheckSsoRedirectUri.

Create a file called silent-check-sso.html in the assets directory of your application and paste in the contents as seen below.

<html>
  <body>
    <script>
      parent.postMessage(location.href, location.origin);
    </script>
  </body>
</html>

If you want to know more about these options and various other capabilities of the Keycloak client is recommended to read the JavaScript Adapter documentation.

AuthGuard

A generic AuthGuard, KeycloakAuthGuard is provided to help you protect authenticated routes in your application. This guard provides you with information to see if the user is logged in and a list of roles from that belong to the user. In your implementation you just need to implement the desired logic to protect your routes.

To write your own implementation extend the KeycloakAuthGuard class and implement the isAccessAllowed method. For example the code provided below checks if the user is authenticated and if not the user is requested to sign in. It also checks if the user has the correct roles which could be provided by passing the roles field into the data of the route.

import { Injectable } from '@angular/core';
import {
  ActivatedRouteSnapshot,
  Router,
  RouterStateSnapshot,
} from '@angular/router';
import { KeycloakAuthGuard, KeycloakService } from 'keycloak-angular';

@Injectable({
  providedIn: 'root',
})
export class AuthGuard extends KeycloakAuthGuard {
  constructor(
    protected readonly router: Router,
    protected readonly keycloak: KeycloakService
  ) {
    super(router, keycloak);
  }

  public async isAccessAllowed(
    route: ActivatedRouteSnapshot,
    state: RouterStateSnapshot
  ) {
    // Force the user to log in if currently unauthenticated.
    if (!this.authenticated) {
      await this.keycloak.login({
        redirectUri: window.location.origin + state.url,
      });
    }

    // Get the roles required from the route.
    const requiredRoles = route.data.roles;

    // Allow the user to to proceed if no additional roles are required to access the route.
    if (!(requiredRoles instanceof Array) || requiredRoles.length === 0) {
      return true;
    }

    // Allow the user to proceed if all the required roles are present.
    return requiredRoles.every((role) => this.roles.includes(role));
  }
}

HttpClient Interceptor

By default all HttpClient requests will add the Authorization header in the format of: Authorization: Bearer TOKEN.

There is also the possibility to exclude a list of URLs that should not have the authorization header. The excluded list must be provided in the keycloak initialization. For example:

await keycloak.init({
  config: {
    url: 'http://localhost:8080/auth',
    realm: 'your-realm',
    clientId: 'your-client-id',
  },
  bearerExcludedUrls: ['/assets', '/clients/public'],
});