Spring Security allows us to use role-based control to restrict access to API resources. However, inserting role names as simple strings can quickly become cumbersome and increase development cost. Fortunately, we can enclose role details in an Enum and use custom annotations to simplify management of user roles in a Spring Boot application. While it still doesn’t provide type-safe roles, most IDEs will be able to support changes in the code and simplify maintenance.
A custom annotation in Spring Boot tests is an easy and flexible way to provide the required configuration. We can use it to efficiently group all the annotations and configuration classes that we would otherwise apply to each test class separately.
Delegating user management to Keycloak allows us to better focus on meeting the business needs of an application. However, we still need to provide the appropriate configuration to translate user roles and privileges between Keycloak and Spring Boot. Additionally, we’re going to need some handy techniques for debugging how roles are converted between the two services.
Swagger offers various methods to authorize requests to our Keycloak secured API. I’ll show you how to implement the recommended grant types and why certain flows are advised against in the OAuth 2.0 specification.
Configuring our Spring Boot API to use Keycloak as an authentication and authorization server can greatly simplify our codebase. However, it adds another external dependency that will complicate the integration testing. As a remedy, we can switch to native Spring Security when executing tests to verify only the business rules for access control instead of cluttering the code with Keycloak dependencies.
Keycloak provides simple integration with Spring applications. As a result, we can easily configure our Spring Boot API security to delegate authentication and authorization to a Keycloak server.
Postman comes with a wide variety of OAuth 2.0 compliant configuration options that allow us to authorize requests against a Keycloak protected API. The current standard recommendation is to use Authorization Code Flow with PKCE extension.
When an API is secured against CSRF attacks, we must ensure that our clients’ requests are adjusted to the security requirements. Learn how to successfully call an API that uses the Cookie-to-header token approach by adding the X-XSRF-TOKEN header to Postman requests.
If we want to import multiple Keycloak realms, or realm resources are split into multiple files, we need to execute a directory import at boot time. Fortunately, running a Keycloak service with Docker makes this task easy.
Running a Keycloak service in a Docker container allows us to share its configuration across multiple environments. However, we can also export an entire Keycloak realm in case we need any backups or data transfer between servers.