why.md

Motivation for Docker Builder

Bob was created out of the need to more easily build, tag, and push layered docker images. Beyond what a normal docker build would offer, Bob offers the following:

0. Build from multiple "Dockerfiles"

• In order for a docker build to have context, the Dockerfile must be present in the code repo and must be named "Dockerfile". Bob makes this possible by performing your builds in a temporary directory, so you can name your Dockerfile whatever you want.

0. Includes & Excludes

• Sometimes, you want to tailor which of your application's files end up in your container, but writing an explicit ADD command for each file and directory is very tedious. Instead, by using Includes and Excludes, your temporary build directory will have only exactly the files you want. That way, instead of adding each file individually, you can simply ADD . <dir>

0. Tagging macros

• More often than not, in addition to a static tag, it is desirable to tag a docker container dynamically with, for example, the git revision of the associated code repo. Bob makes this easy for you with tagging macros.

0. Seamless, reliable build, tag, & push process

• A typical docker build workflow can be a bit tedious and nuanced. Bob aims to abstract all of this and make the process much simpler
• Simply write your Dockerfile and let Bob take care of the rest!