The majority of the time, Docker is synonymous to microservices. Running a big monolithic application in Docker does not make too much sense as the whole Docker Engine is thought to be running big applications split into different and smaller services. There is no technical limitation to running a monolithic app on Docker, but when the orchestration software comes into place (in the following chapters), it really defeats the purpose of containerization. When dealing with microservices, it is very common to have several services running at the same time when developing, as the new services will lean on the existing ones to execute operations. In order to achieve this setup, Docker facilitates a tool called docker-compose that, by creating a YAML file with the definition of our containers, can spawn a full ecosystem of containers. Docker compose used to be very popular in the beginning of Docker. Nowadays, it is still widely used, but its space has been slowly reduced to development...