Understanding the use of Docker stacks

So far, we have mostly been looking at running a Docker container from a single Docker image, simplifying the Docker model to imagine a world where every application only required a single service, and thus a single Docker image, to run. However, as you know, that is a pretty unrealistic model. Real-world applications are composed of multiple services, and those services are deployed using multiple Docker images. To run all of the necessary containers, and maintain them at the desired number of replicas, handling planned and unplanned downtimes, scaling requirements and all of the other service management needs is a really daunting and complex task. In the recent past, this scenario was handled using a tool called Docker Compose. Docker Compose (as you learned in Chapter 1, Setting up a Docker Development Environment) is an additional tool...