Reproducibility is the key reason I use Docker. Some stuff is really tricky to setup too - like postfix with working TLS, DKIM etc. Before Docker I'd eventuall

Reproducibility is the key reason I use Docker. Some stuff is really tricky to setup too - like postfix with working TLS, DKIM etc. Before Docker I'd eventually get stuff like this working, then a couple of years something would break and I'd have no clue how to fix it because I hadn't touched it for so long. With Docker (and Compose and Swarm), everything is codified in scripts and config files, all ready to be deployed anywhere.