BUILD.md

How to build boot2docker locally

boot2docker is built with Docker, via Dockerfiles.

It is composed in three distinct steps:

• base: fetches, patches with AUFS support and builds the 3.13.3 Linux Kernel with Tiny Core base configuration
• rootfs: builds the base rootfs for boot2docker (not complete)
• running rootfs: when you run this image, it will build the rootfs, download the latest Docker release and create the .iso file on / of the container.

So the full build process goes like this:

$ sudo docker build -t boot2docker/boot2docker:base base/
$ sudo docker build -t boot2docker/boot2docker-rootfs rootfs/
$ sudo docker rm build-boot2docker
# you will need more than 2GB memory for the next step
$ sudo docker run --privileged --name build-boot2docker boot2docker/boot2docker-rootfs
$ sudo docker cp build-boot2docker:/boot2docker.iso .

Now you can install the iso to a USB drive, SD card, CD-Rom or hard-disk. The image contains a Master Boot Record, and a partition table, so can be written to a raw device.

    sudo dd if=boot2docker.iso of=/dev/sdX

Making your own customised boot2docker ISO

The boot2docker release process takes advantage of docker.io Trusted Builds so rather than modifying the 2 Dockerfiles and re-building from scratch, you can make a new Dockerfile that builds FROM boot2docker/boot2docker-rootfs and then run that to generate your boot2docker.iso file:

$ sudo docker pull boot2docker/boot2docker-rootfs
$ echo "FROM boot2docker/boot2docker-rootfs" > Dockerfile
$ echo "ADD . /data/" >> Dockerfile
$ echo "RUN somescript.sh" >> Dockerfile

$ sudo docker build -t my-boot2docker-img .
$ sudo docker rm my-boot2docker
$ sudo docker run --privileged -name my-boot2docker my-boot2docker-img
$ sudo docker cp my-boot2docker:/boot2docker.iso .