Automated Grey-Box Testing of Microservice Architectures

Microservices Architectures (MSA) have found large adoption in companies delivering online services, often in conjunction with agile development practices. Microservices are distributed, independent and polyglot entities - all features favouring black-box testing. However, for real-scale MSA, a pure black-box strategy may not be able to exercise the system to properly cover the interactions involving internal microservices. We propose a grey-box strategy (MACROHIVE) for automated testing and monitoring of (internal) microservices interactions. It uses combinatorial testing to generate valid and invalid tests from microservices specification. Tests execution and monitoring are automated by a service mesh infrastructure. MACROHIVE runs the tests and traces the interactions among microservices, to report about internal coverage and failing behaviour. MACROHIVE is experimented on TrainTicket, an open-source MSA benchmark. It performs comparably to state-of-the-art techniques in terms of edge-level coverage, but exposes internal failures undetected by black-box testing, gives detailed internal coverage information, and requires fewer tests.