Life is easy without dependencies. In real life, however, almost every application links to a database, cache, messaging system, or another application. In the case of (micro) service architecture, each service needs a bunch of other services to do its work. The monolithic architecture does not eliminate the issue—an application usually has some dependencies, at least to the database.
Imagine a newcomer joining your development team; how much time does it take to set up the entire development environment and run the application with all its dependencies?
When it comes to automated acceptance testing, the dependencies issue is no longer only a matter of convenience—it becomes a necessity. While, during unit testing, we could mock the dependencies, the acceptance testing suite requires a complete environment. How do we set it up quickly and in a repeatable manner? Luckily, Kubernetes can help thanks to its built-in DNS resolution for services and Pods.