Keycloak integration in Swagger

Question

I have a Keycloak protected backend that I would like to access via swagger-ui. Keycloak provides the oauth2 implicit and access code flow, but I was not able to make it wor

Answer 1

Was struggling with this setup for the past 2 days. Finally got a working solution for those who cannot resolve.

pom.xml

    ...
    
        org.keycloak
        keycloak-spring-security-adapter
    
    
        org.keycloak
        keycloak-spring-boot-starter
    
    ...

Enable Swagger on main class

...    
import springfox.documentation.swagger2.annotations.EnableSwagger2;

@SpringBootApplication
@EnableSwagger2
@EnableAsync
@EnableCaching
public class MainApplication {
  public static void main(String[] args) {
    SpringApplication app = new SpringApplication(MainApplication.class);
    app.run(args);
  }
}

SwaggerConfig.java

package com.XXX.XXXXXXXX.app.config;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.AuthorizationCodeGrantBuilder;
import springfox.documentation.builders.OAuthBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.service.*;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spi.service.contexts.SecurityContext;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger.web.SecurityConfiguration;
import springfox.documentation.swagger.web.SecurityConfigurationBuilder;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

import java.util.Arrays;

import static springfox.documentation.builders.PathSelectors.regex;

/*
 * Setting up Swagger for spring boot
 * https://www.baeldung.com/swagger-2-documentation-for-spring-rest-api
 */
@Configuration
@EnableSwagger2
public class SwaggerConfig {

 @Value("${keycloak.auth-server-url}")
 private String AUTH_SERVER;

 @Value("${keycloak.credentials.secret}")
 private String CLIENT_SECRET;

 @Value("${keycloak.resource}")
 private String CLIENT_ID;

 @Value("${keycloak.realm}")
 private String REALM;

 private static final String OAUTH_NAME = "spring_oauth";
 private static final String ALLOWED_PATHS = "/directory_to_controllers/.*";
 private static final String GROUP_NAME = "XXXXXXX-api";
 private static final String TITLE = "API Documentation for XXXXXXX Application";
 private static final String DESCRIPTION = "Description here";
 private static final String VERSION = "1.0";

 @Bean
 public Docket taskApi() {
   return new Docket(DocumentationType.SWAGGER_2)
    .groupName(GROUP_NAME)
    .useDefaultResponseMessages(true)
    .apiInfo(apiInfo())
    .select()
    .paths(regex(ALLOWED_PATHS))
    .build()
    .securitySchemes(Arrays.asList(securityScheme()))
    .securityContexts(Arrays.asList(securityContext()));
 }

 private ApiInfo apiInfo() {
   return new 
     ApiInfoBuilder().title(TITLE).description(DESCRIPTION).version(VERSION).build();
 }

 @Bean
 public SecurityConfiguration security() {
   return SecurityConfigurationBuilder.builder()
    .realm(REALM)
    .clientId(CLIENT_ID)
    .clientSecret(CLIENT_SECRET)
    .appName(GROUP_NAME)
    .scopeSeparator(" ")
    .build();
 }

 private SecurityScheme securityScheme() {
   GrantType grantType =
    new AuthorizationCodeGrantBuilder()
        .tokenEndpoint(new TokenEndpoint(AUTH_SERVER + "/realms/" + REALM + "/protocol/openid-connect/token", GROUP_NAME))
        .tokenRequestEndpoint(
            new TokenRequestEndpoint(AUTH_SERVER + "/realms/" + REALM + "/protocol/openid-connect/auth", CLIENT_ID, CLIENT_SECRET))
        .build();

SecurityScheme oauth =
    new OAuthBuilder()
        .name(OAUTH_NAME)
        .grantTypes(Arrays.asList(grantType))
        .scopes(Arrays.asList(scopes()))
        .build();
return oauth;
 }

 private AuthorizationScope[] scopes() {
AuthorizationScope[] scopes = {
  new AuthorizationScope("user", "for CRUD operations"),
  new AuthorizationScope("read", "for read operations"),
  new AuthorizationScope("write", "for write operations")
};
return scopes;
}

private SecurityContext securityContext() {
return SecurityContext.builder()
    .securityReferences(Arrays.asList(new SecurityReference(OAUTH_NAME, scopes())))
    .forPaths(PathSelectors.regex(ALLOWED_PATHS))
    .build();
 }
}

From terminal, run "mvnw spring-boot:run"

Open browser and hit http://localhost:[port]/[app_name]/swagger-ui.html.

Click the Authorize button: Swagger Authorize Button

This should present a modal to confirm your keycloak settings.

Click Authorize button once again. You should be redirected to a login screen.

Once credentials are entered and confirmed, you will be redirected back to Swagger-UI fully authenticated.