acbuild is a command line utility to build and modify App Container Images (ACIs), the container image format defined in the App Container (appc) spec.

We needed a powerful tool for constructing and manipulating ACIs that made it easy to iteratively build containers, both from scratch and atop existing images. We wanted that tool to integrate well with Unix mechanisms like the shell and Makefiles so it would fit seamlessly into well-known administrator and developer workflows.

acbuild can only be run on a Linux system, and has only been tested on the amd64 architecture.

For trying out acbuild on Mac OS X, it's recommended to use Vagrant. Instructions on how to do this are a little further down in this document.

acbuild requires a handful of commands be available on the system on which it's run:

• systemd-nspawn
• cp
• modprobe
• gpg

The easiest way to get acbuild is to download one of the releases from GitHub.

The other way to get acbuild is to build it from source.

Follow these steps to do so:

1. Grab the source code for acbuild by git cloneing the source repository:

   cd ~
   git clone https://github.com/appc/acbuild
   

2. Run the build script from the root source repository directory:

   cd acbuild
   ./build
   

   Or, if you want to build in docker (assuming $PWD exists and contains acbuild/ on your Docker host):

   cd acbuild
   ./build-docker
   

3. A bin/ directory will be created that contains the acbuild tool. To make sure your shell can find this executable, append this directory to your environment's $PATH variable. You can do this in your .bashrc or similar file, for example:

   vi ~/.bashrc
   

and put the following lines at the end of the file:

export ACBUILD_BIN_DIR=~/acbuild/bin
export PATH=$PATH:$ACBUILD_BIN_DIR

For users with Vagrant 1.5.x or greater, there's a provided Vagrantfile that can quickly get you set up with a Linux VM that has both acbuild and rkt. The following steps will grab acbuild, set up the machine, and ssh into it.

git clone https://github.com/appc/acbuild
cd acbuild
vagrant up
vagrant ssh

Documentation about acbuild and many of its commands is available in the Documentation directory in this repository.

Check out the examples directory for some common applications being packaged into ACIs with acbuild.

• https://github.com/sgotti/baci
• https://github.com/appc/spec/tree/master/actool - particularly the build and patch-manifest subcommands. acbuild may subsume such functionality, leaving actool as a validator only.
• https://github.com/blablacar/cnt