Building Citadel

Set up Docker

Building citadel requires that you have Docker CE installed on the build host. The version of Docker provided by your Linux distribution will probably not work and you should follow the following instructions instead:

• Installing Docker CE on Debian
• Installing Docker CE on Fedora

After installing Docker you may need to start the docker daemon.

$ systemctl start docker

If you want the docker daemon to start automatically on boot you also need to enable it.

$ systemctl enable docker

You may optionally add your user account to the docker group so that you can issue docker commands without using sudo.

Warning: This is more convenient but be careful because containers can be configured to share any file on the host. A user with access to the docker group can easily escalate privileges to root while the docker daemon is running.

$ sudo usermod -aG docker $USER

Building with Docker

A Makefile is provided which only contains a couple of simple targets that execute docker commands to set up and run the builder container.

The project uses git submodules to track openembedded layers it depends upon. After cloning this repository you will need to retrieve the dependent submodules with the following command:

$ make update-submodules

To create the builder docker image use the following command. You only need to do this one time, but if you run it again Docker will realize that the Dockerfile has not changed and do nothing.

$ make docker-image

To list available make targets, run make help or just make as this is the default target:

$ make help

To run a shell inside the docker build container:

$ make docker-shell

The shell will run in the build directory and be configured to run build commands with bitbake.

To build a full citadel image:

$ make citadel-image

The build will take several hours the first time, but for later builds the build system will use cached artifacts stored in citadel/build/sstate-cache for components that have not changed and new builds will usually only take a few minutes.

Some Assembly Required

Currently there are some rather unreliable scripts to make it possible to turn build output into something that you can install and run.

Very soon these scripts will be replaced by an actual installer that you can just build by running a make target, but that doesn't quite exist yet.

Running scripts/create_install_pack to create installpack.tar

Before creating the installpack, some artifacts must exist in the build/images directory:

• make citadel-image Creates: images/citadel-image-intel-corei7-64.ext2
• make citadel-kernel Creates: images/bzImage
• make bootloader Creates: images/systemd-bootx64.efi
• make appimg-rootfs Creates: appimg/appimg-rootfs.tar.xz

After all of those components have been build, you can run scripts/create_install_pack which will create a file in the current directory called installpack.tar.

You can then unpack this tarball somewhere and run a script inside of it called install.sh to install to a USB stick (do this first, at least until you understand the process) or to install to internal disk drive.

$ tar xvf installpack.tar
$ cd installpack
$ sudo ./install.sh /dev/sdb

The install.sh script redirects all output from the commands it runs to a file install.log in the current directory. If the last line of output does not say "Install completed successfully" then something failed. Look in install.log for information about what went wrong. The script itself does not print any output when it fails, it will just stop at one of the steps and it appears as if everything worked since there is no error output.

Reproducible builds

Citadel is configured to reproducibly build artifacts. At this stage, we are not yet at 100% reprodubility. We have included a script to track the gaps in reproducibility.

This requires performing two independent builds of Citadel (preferably on the same host, doing this on different hosts is an exercise left up to the user).

The first build is the test build and the second build is the control build. To compare the two, run the repro_gaps.sh script in the scripts directory of this repo.

By default, it will produce a summary table showing how many packages have been built reproducibly across the test and control builds. For example:

$ ./repro_gaps.sh /home/user/src/citadel /home/user/src/citadel-control

To generate a list of the packages that were not reproducible, the script can be run with the --output option:

$ ./repro_gaps.sh /home/user/src/citadel /home/user/src/citadel-control --output gaps.txt