[ArchD]

Docker lets you document/codify the steps used to setup a machine or service.

The Dockerfile contains the steps for creating the image. With docker-compose, you can codify how to setup services.

This is better than the alternative of doing everything by hand, with manual commands and adhoc edits to random system config files. The manual way is error-prone and not easily repeatable.

I use docker-compose for our internal gerrit, wiki and XMPP server setup.

If I were to do this setup by hand e.g. on a real machine or VM with manual edits to random config files all over the place, it is not clear exactly what I need to backup or how I would rebuild the server if it were destroyed somehow.

With docker-compose, the data I need to backup is all in one directory on the host machine and the services/servers themselves can be recreated from the Dockerfile and docker-compose.