Ory Dockertest, an open-source project, aims to streamline database testing in cloud-native applications by leveraging Docker, allowing developers to automate the setup and teardown of real databases for testing purposes without needing to establish a complete database infrastructure. This tool, created within the Ory ecosystem, simplifies the process of testing integration of services with databases by enabling the use of real databases instead of cumbersome mock systems. Dockertest's utility is highlighted by its adoption in Google's open-source reference implementation for the Covid-19 Exposure Notification system, demonstrating its reliability and essential role in large-scale projects. The broader impact of open-source software, as exemplified by Dockertest, is seen in its potential to drive innovation and collective action across public infrastructure and services, offering transparency and trust in essential digital infrastructure.