Microservices are definitely the hot topic du jour . Everyone ( and their dog ) is using microservices or migrating towards them. To make things more interesting, the OSGi community has been talking about microservices for 6 years now, so now we have two clashing definitions of the term.
Besides the dreaded monolith and the famed microservices-based architecture there is plenty of room for a middle ground, where an API gateway mediates between a host of microservices and their consumers. Such a gateway solves multiple cross-cutting concerns, such as authentication, API standardisation, logging and decoupling the API evolution. As it turns out, OSGi is an ideal setting for building such an application.
The API gateway implementation demoed is based on Apache Sling - an innovative web framework built on top of the Java Content Repository (JCR), that uses OSGi for its component model and fosters RESTful application design. Although we will use Apache Sling for examples, previous knowledge of Sling or its components is not required.