In this article, we present our findings and conclusions derived from our implementation of a “proof-of-concept” Keycloak extension. This extension integrates a relational database containing user information with the identity provider (abbreviated as “IdP”) Keycloak [1]. Within the Keycloak framework, such an extension is referred to as a “custom user storage provider,” which we will shorthand as “the custom provider” throughout this article.

The article begins by elucidating the motivation behind developing this custom provider, outlining its scope and objectives. Subsequently, it delves into the design decisions made and the intended data flow, accompanied by an explanation of the technical approach adopted. Finally, the article discusses the challenges and issues encountered during the implementation process.