Spring Security OAuth 2 Tutorial - 10 : Service to Service Communication using Client Credentials Flow

Step-by-step guide to implementing service-to-service communication using the OAuth2 Client Credentials Flow with Spring Boot and Keycloak. Covers creating a Keycloak client with service account roles, configuring a Spring Boot service as both a Resource Server and OAuth2 Client, obtaining access tokens programmatically via OAuth2AuthorizedClientManager, and invoking secured APIs using RestTemplate with Bearer tokens. Also includes a scheduled job for periodic archival and a best-practice note on using dedicated roles instead of ROLE_ADMIN for machine-to-machine flows.