How to Securely Connect Backend Services with Spring Boot and Keycloak

Frontend and Backend Development
1

I face issues obtaining an access token via Keycloak for inter-service communication using Spring Boot. How should I adjust settings to allow proper token retrieval? See sample below.

public class TokenFetcher {
    public String fetchToken(String serviceIdentifier) {
        MySecureClient secureClient = new MySecureClient();
        return secureClient.retrieveToken("serviceIdentifier");
    }
}
2

hey, im tryin a custom cached token approach for inter-servce comms. has any1 experinced issues with token lifetimes in keycloack after tweaking client configs? i wonder if combining caching with refined realm settings might resolve the reuqests more efficiently. any thots?

3

Based on experience, it is crucial to ensure that the backend client in Keycloak is configured to support the correct grant type for inter-service communication. Rather than relying on hardcoded values, setting up properties to securely store client secrets and IDs provides more flexibility and security. I encountered similar issues where adjusting the client and realm configurations, particularly enabling direct access grants, helped resolve the token retrieval problems. Furthermore, verifying that the Spring Boot application is correctly aligned with the Keycloak adapter settings mitigated the issues in my own integration work.

4

hey, check that u didnt miss any config in keycloak for the correct grant type. sometimes a bad realm setup messes up token fetching. look at your scopes and endpoints, a simple typo in secret id can cause issues.