These are the Ubuntu Core images as downloadable from Ubuntu. See the Ubuntu Core wiki page for more information. The following Ubuntu versions will be built:

• 14.04, trusty
• 13.10, saucy
• 12.04, precise

The images were made using the script build-all.sh.

Usage

Just use FROM mazzolino/armhf-ubuntu:<VERSION> in your Dockerfile to use pre-built images from the Docker index. I will update the images regularly (I promise).

Alternatively, you can build and push your own images, as described in the following section.

Building

You can build and push your own version of the images to the Docker index. Building is possible on armhf ("armv7l") as well as x86 machines (64 bits only, as that is what Docker supports). See the section on Emulation support on how to install the prerequisites.

Build all distributions:

./build-all.sh

Build a specific Ubuntu version:

./build.sh 14.04

Images will automatically pushed as <YOUR-DOCKER-USER>/armhf-docker.

Emulation support

The image includes the amd64 version of qemu-arm-static. This means you can build and run ARM containers on your 64bit machine, as explained in this post. The following command must be executed before building or running any ARM containers (the build script does this automatically):

sudo sh -c 'echo ":arm:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/bin/qemu-arm-static:" >/proc/sys/fs/binfmt_misc/register'

Tagging

Tip: On your arm device, additionally tag the images as ubuntu in order to be able to build Dockerfiles which use the ubuntu base image:

docker tag -f mazzolino/armhf-ubuntu:14.04 ubuntu:14.04
docker tag -f mazzolino/armhf-ubuntu:14.04 ubuntu:latest
docker tag -f mazzolino/armhf-ubuntu:14.04 ubuntu:trusty

docker tag -f mazzolino/armhf-ubuntu:13.10 ubuntu:13.10
docker tag -f mazzolino/armhf-ubuntu:13.10 ubuntu:saucy

docker tag -f mazzolino/armhf-ubuntu:12.04 ubuntu:12.04
docker tag -f mazzolino/armhf-ubuntu:12.04 ubuntu:precise

# Maybe also the stackbrew images
docker tag mazzolino/armhf-ubuntu:12.04 stackbrew/ubuntu:12.04
[...]

Look at the official Ubuntu image description to see what else should be tagged.