Testcontainers is a great tool for local development and testing in order to spin up containers that mimick the actual environment to test against. It has frameworks for almost every programming language for easy to use integration. Sadly, it uses Docker under the hood and does not want to support other container runtimes like kubernetes. Since many GitLab Runners are hosted inside a Kubernetes cluster or do not want to expose the Docker socket for security reasons, testcontainers does not work ...