Various Dockerfiles and Docker-Compose files.
For "playground", in ci-cd-automation, DevOps topics and IaaS providers.
Most of the images are published to n13.org on Docker Hub. Docker Hub offers a free plan or select a payed plan, Pricing of Docker Hub.
A Dockerfile can have an entrypoint file. The last command inside the entrypoint.sh file can be exec "$@"to execute the CMD command after the endpoint is done.
The folder _compose contains Docker-Compose examples, each folder is a project.