Testcontainers has become the go-to solution for integration testing in the Java community. A key factor behind its popularity is its rich ecosystem of modules—predefined abstractions that allow you to spin up containerized services for your tests with just a single line of code.

But what if your projects frequently rely on a specific in-house technology and there is no Testcontainers module for it? Instead of repeatedly writing and copying integration code across different projects, you can build a custom Testcontainers module. It will help you to tailor Testcontainers to your needs, abstract away complexity, and ensure smooth integration with your internal Docker images.

In this lab, we’ll explore the architecture of a Testcontainers module, walk through the implementation process, and build couple of useful modules from scratch.

Whether you're working with databases, experimenting with chaos engineering, or looking to improve your team's testing workflow, creating a custom Testcontainers module is a powerful way to streamline integration testing and contribute to the Java ecosystem.