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Using Keycloak Admin Client

The Quarkus Keycloak Admin Client and its reactive twin support Keycloak Admin Client which can be used to configure a running Keycloak server.

This guide demonstrates how you can leverage the Quarkus ArC and inject the admin client to your Quarkus application, as well as how to create it directly in the application code.

To learn more about the Keycloak Admin Client, please refer to its reference guide.

Requisitos previos

To complete this guide, you need:

  • Roughly 15 minutes

  • An IDE

  • JDK 17+ installed with JAVA_HOME configured appropriately

  • Apache Maven 3.9.6

  • A working container runtime (Docker or Podman)

  • Optionally the Quarkus CLI if you want to use it

  • Optionally Mandrel or GraalVM installed and configured appropriately if you want to build a native executable (or Docker if you use a native container build)

  • Keycloak

Creating the Project

En primer lugar, necesitamos un nuevo proyecto. Cree un nuevo proyecto con el siguiente comando:

CLI
quarkus create app org.acme:security-keycloak-admin-client \
    --extension='keycloak-admin-rest-client,rest-jackson' \
    --no-code
cd security-keycloak-admin-client

To create a Gradle project, add the --gradle or --gradle-kotlin-dsl option.

For more information about how to install and use the Quarkus CLI, see the Quarkus CLI guide.

Maven
mvn io.quarkus.platform:quarkus-maven-plugin:3.9.4:create \
    -DprojectGroupId=org.acme \
    -DprojectArtifactId=security-keycloak-admin-client \
    -Dextensions='keycloak-admin-rest-client,rest-jackson' \
    -DnoCode
cd security-keycloak-admin-client

To create a Gradle project, add the -DbuildTool=gradle or -DbuildTool=gradle-kotlin-dsl option.

For Windows users:

  • If using cmd, (don’t use backward slash \ and put everything on the same line)

  • If using Powershell, wrap -D parameters in double quotes e.g. "-DprojectArtifactId=security-keycloak-admin-client"

This command generates a project which imports the keycloak-admin-rest-client and rest-jackson extensions.

If you already have your Quarkus project configured, you can add the keycloak-admin-rest-client and rest-jackson extensions to your project by running the following command in your project base directory:

CLI
quarkus extension add keycloak-admin-rest-client,rest-jackson
Maven
./mvnw quarkus:add-extension -Dextensions='keycloak-admin-rest-client,rest-jackson'
Gradle
./gradlew addExtension --extensions='keycloak-admin-rest-client,rest-jackson'

Esto añadirá lo siguiente a su archivo de construcción:

pom.xml
<dependency>
    <groupId>io.quarkus</groupId>
    <artifactId>quarkus-keycloak-admin-rest-client</artifactId>
</dependency>
<dependency>
    <groupId>io.quarkus</groupId>
    <artifactId>quarkus-rest-jackson</artifactId>
</dependency>
build.gradle
implementation("io.quarkus:quarkus-keycloak-admin-rest-client")
implementation("io.quarkus:quarkus-rest-jackson")

We also are going to need a simple resource with a Keycloak injected as request scoped CDI bean.

package org.acme.keycloak.admin.client;

import org.keycloak.admin.client.Keycloak;
import org.keycloak.representations.idm.RoleRepresentation;

import jakarta.inject.Inject;
import jakarta.ws.rs.GET;
import jakarta.ws.rs.Path;
import java.util.List;

@Path("/api/admin")
public class RolesResource {

        @Inject
        Keycloak keycloak; (1)

        @GET
        @Path("/roles")
        public List<RoleRepresentation> getRoles() {
            return keycloak.realm("quarkus").roles().list();
        }

}
1 Create a default Keycloak Admin Client which can perform Keycloak master realm administration tasks as an admin-cli client, such as adding new realms, clients and users.

The only configuration which is required to create this Keycloak Admin Client is a Keycloak server URL.

For example:

# Quarkus based Keycloak distribution
quarkus.keycloak.admin-client.server-url=http://localhost:8081

or

# WildFly based Keycloak distribution
quarkus.keycloak.admin-client.server-url=http://localhost:8081/auth

It is important that quarkus.keycloak.admin-client.server-url is configured if you would like to have Keycloak injected. The injection will fail if you attempt to inject Keycloak without configuring this property.

Injecting Keycloak Admin Client instead of creating it directly in the application code is a simpler and more flexible option but you can create the same admin client manually if necessary:

package org.acme.keycloak.admin.client;

import org.keycloak.admin.client.Keycloak;
import org.keycloak.admin.client.KeycloakBuilder;
import org.keycloak.representations.idm.RoleRepresentation;

import jakarta.annotation.PostConstruct;
import jakarta.annotation.PreDestroy;
import jakarta.ws.rs.GET;
import jakarta.ws.rs.Path;
import java.util.List;

@Path("/api/admin")
public class RolesResource {

        Keycloak keycloak;

        @PostConstruct
        public void initKeycloak() {
            keycloak = KeycloakBuilder.builder()
                .serverUrl("http://localhost:8081")
                .realm("master")
                .clientId("admin-cli")
                .grantType("password")
                .username("admin")
                .password("admin")
                .build();
        }

        @PreDestroy
        public void closeKeycloak() {
            keycloak.close();
        }

        @GET
        @Path("/roles")
        public List<RoleRepresentation> getRoles() {
            return keycloak.realm("quarkus").roles().list();
        }

}

For more details consult Keycloak Admin REST API documentation.

You can configure Keycloak Admin Client to administer other realms and clients. It can use either a password or client_credentials grant to acquire an access token to call the Admin REST API which requires authorization.

If you exchange user’s credentials for the access token, here is an example configuration for the password grant type:

quarkus.keycloak.admin-client.server-url=http://localhost:8081
quarkus.keycloak.admin-client.realm=quarkus
quarkus.keycloak.admin-client.client-id=quarkus-client
quarkus.keycloak.admin-client.username=alice
quarkus.keycloak.admin-client.password=alice
quarkus.keycloak.admin-client.grant-type=PASSWORD (1)
1 Use password grant type.

An example using the client-credentials grant type needs only a minor adjustments:

quarkus.keycloak.admin-client.enabled=true
quarkus.keycloak.admin-client.server-url=http://localhost:8081
quarkus.keycloak.admin-client.realm=quarkus
quarkus.keycloak.admin-client.client-id=quarkus-client
quarkus.keycloak.admin-client.client-secret=secret
quarkus.keycloak.admin-client.username= # remove default username
quarkus.keycloak.admin-client.password= # remove default password
quarkus.keycloak.admin-client.grant-type=CLIENT_CREDENTIALS (1)
1 Use client_credentials grant type.
Note that the OidcClient can also be used to acquire tokens.

Probando

The preferred approach for testing Keycloak Admin Client against Keycloak is Dev Services for Keycloak. Dev Services for Keycloak will start and initialize a test container. Then, it will create a quarkus realm and a quarkus-app client (secret secret) and add alice (admin and user roles) and bob (user role) users, where all of these properties can be customized.

For example, by default, a test container will be available at a randomly allocated port but you can make both Keycloak Admin Client and the container use the same port as follows:

%test.quarkus.keycloak.devservices.port=${kc.admin.port.test:45180} (1)
%test.quarkus.keycloak.admin-client.server-url=http://localhost:${kc.admin.port.test:45180}/ (2)
1 Configure the Keycloak container to listen on the 45180 port by default
2 Configure the Keycloak Admin Client to use the same port

Quarkus Keycloak Admin Client Configuration Reference

Configuration property fixed at build time - All other configuration properties are overridable at runtime

Configuration property

Tipo

Por defecto

Set to true if Keycloak Admin Client injection is supported.

Environment variable: QUARKUS_KEYCLOAK_ADMIN_CLIENT_ENABLED

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boolean

true

Keycloak server URL, for example, https://host:port. If this property is not set then the Keycloak Admin Client injection will fail - use org.keycloak.admin.client.KeycloakBuilder to create it instead.

Environment variable: QUARKUS_KEYCLOAK_ADMIN_CLIENT_SERVER_URL

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string

Realm.

Environment variable: QUARKUS_KEYCLOAK_ADMIN_CLIENT_REALM

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string

master

Client id.

Environment variable: QUARKUS_KEYCLOAK_ADMIN_CLIENT_CLIENT_ID

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string

admin-cli

Client secret. Required with a client_credentials grant type.

Environment variable: QUARKUS_KEYCLOAK_ADMIN_CLIENT_CLIENT_SECRET

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string

Username. Required with a password grant type.

Environment variable: QUARKUS_KEYCLOAK_ADMIN_CLIENT_USERNAME

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string

admin

Password. Required with a password grant type.

Environment variable: QUARKUS_KEYCLOAK_ADMIN_CLIENT_PASSWORD

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string

admin

OAuth 2.0 Access Token Scope.

Environment variable: QUARKUS_KEYCLOAK_ADMIN_CLIENT_SCOPE

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string

OAuth Grant Type.

Environment variable: QUARKUS_KEYCLOAK_ADMIN_CLIENT_GRANT_TYPE

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password, client-credentials

password