This is a Docker build environment container for buildroot. You can use this container to produce a root filesystem tar that you can use for building BusyBox containers from scratch. See the example directory for how you'd normally use rootbuilder.
The rootbuilder container is just a pre-setup build environment with a ready-to-go buildroot directory. Using this, you can put together an easy workflow to configure and build a rootfs.
As you can see in the example directory, the Dockerfile is used to make buildroot using a configuration file. The Makefile gives you your main workflow tasks. The
config task just runs
make nconfig in rootbuild and pulls out the
.config file. The
build task then executes docker build from the Dockerfile, which uses the configuration file, resulting in a container that will have a rootfs artifact that the build task extracts.
In other words, you can copy the example directory as a directory in your project, then in it run:
$ make config
And you'll get an interactive menu to define a buildroot configuration. The configuration will get stored in that directory and used when you run:
$ make build
Which will take forever to run, but ultimately put a
rootfs.tar in the directory. And all the messy stuff happens inside Docker.
This project was made possible thanks to DigitalOcean.