Dapper is a tool to wrap any existing build tool in an consistent environment. This allows people to build your software from source or modify it without worrying about setting up a build environment. The approach is very simple and taken from a common pattern that has adopted by many open source projects. Create a file called Dockerfile.dapper in the root of your repository. Dapper will build that Dockerfile and then execute a container based off of the resulting image. Dapper will also copy in source files and copy out resulting artifacts or will use bind mounting if you choose.The Dockerfile.dapper is intended to create a build environment but not really build your code. For example if you need build tools such as make or bundler or language environments for Ruby, Python, Java, etc.