Is your team waiting until deployment to test the contents and configuration of your Docker images? Test Driven Development isn't just for application code. Apply it to your infrastructure code as well! You'll learn about multiple tools available to verify the output of Dockerfiles and test running containers. Adding one of these tools into your developer build and CI/CD pipeline can detect errors and regressions earlier, making them less costly to fix. It's time to replace `docker run` as your testing tool of choice for Docker.