Using OpenAPI 3 Specifications of the 5G Core to Generate Validators in Erlang

Abstract

Most of the 5G Core network components are virtualized and designed as RESTful APIs, communicating between each other by sending HTTP requests. These requests are defined in the 3GPP 5G Core official specifications following the OpenAPI 3 format. In this thesis we explore the current status of Erlang code generation from OpenAPI 3 specifications and its use for validation in Ericsson’s 5G Core system. The best candidate tool for the project was OpenAPI Generator, although it required several fixes to be used. Based on Ericsson’s internal test environment, we show that it is possible to integrate the generated code for request validation in it. The integration was successful as it found two bugs in the system, but it highlighted the lack of support for some advanced features. These shortcomings indicate that Erlang code generation from OpenAPI 3 is good enough for testing but not for production.