How to build boot2docker.iso locally

The boot2docker.iso is built with Docker, via a Dockerfile.

During docker build we

• fetch, patch with AUFS support and build the 3.15.3 Linux Kernel with Tiny Core base configuration
• build the base rootfs for boot2docker (not complete)
• build the rootfs, download the latest Docker release and create the .iso file on / of the container.

Running the resultant image will cat the iso file to STDOUT.

So the full build process goes like this:

# you will need more than 2GB memory
$ docker build -t boot2docker . && docker run --rm 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.iso release process takes advantage of Docker Hub's Automated Builds so rather than modifying the Dockerfile and re-building from scratch, you can make a new Dockerfile that builds FROM boot2docker/boot2docker and then run that to generate your boot2docker.iso file:

$ sudo docker pull boot2docker/boot2docker
$ echo "FROM boot2docker/boot2docker" > Dockerfile
$ echo "ADD . $ROOTFS/data/" >> Dockerfile
$ echo "RUN somescript.sh" >> Dockerfile
$ echo "RUN /tmp/make_iso.sh" >> Dockerfile
$ echo 'CMD ["cat", "boot2docker.iso"]' >> Dockerfile

$ sudo docker build -t my-boot2docker-img .
$ sudo docker run --rm my-boot2docker-img > boot2docker.iso