Wladimir J. van der Laan
For example Ubuntu installs a bridge called `virbr0` by default for LXC. Using this system-provided bridge avoids having to configure one specifically before gitian building. This commits makes it possible to override the bridge used by gitian using the environment variable LXC_BRIDGE. The default is still to use `br0` as before.
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Read about the project goals at the project home page.
This package can do a deterministic build of a package inside a VM.
Deterministic build inside a VM
This performs a build inside a VM, with deterministic inputs and outputs. If the build script takes care of all sources of non-determinism (mostly caused by timestamps), the result will always be the same. This allows multiple independent verifiers to sign a binary with the assurance that it really came from the source they reviewed.
layman -a luke-jr # needed for vmbuilder sudo emerge dev-vcs/git net-misc/apt-cacher-ng app-emulation/vmbuilder dev-lang/ruby sudo emerge app-emulation/qemu export KVM=qemu-system-x86_64
sudo apt-get install git apache2 apt-cacher-ng python-vm-builder ruby qemu-utils sudo apt-get install qemu-kvm # for KVM mode sudo apt-get install debootstrap lxc # for LXC mode
OSX with MacPorts:
sudo port install ruby coreutils export PATH=$PATH:/opt/local/libexec/gnubin # Needed for sha256sum
Install virtualbox from http://www.virtualbox.org, and make sure
VBoxManage is in your
Create the base VM for use in further builds
sudo, please review the script
bin/make-base-vm bin/make-base-vm --arch i386
bin/make-base-vm --lxc bin/make-base-vm --lxc --arch i386
USE_LXC environment variable to use
LXC instead of
VBoxManage must be in your
make-base-vm cannot yet make VirtualBox virtual machines ( patches welcome, it should be possible to use
VBoxManage, boot-from-network Linux images and PXE booting to do it). So you must either get or manually create VirtualBox machines that:
- Are named
Gitian-<suite>-<arch>-- e.g. Gitian-lucid-i386 for a 32-bit, Ubuntu 10 machine.
- Have a booted-up snapshot named
Gitian-Clean. The build script resets the VM to that snapshot to get reproducible builds.
- Has the VM's NAT networking setup to forward port
localhost:2223on the host machine to port
22of the VM; e.g.:
VBoxManage modifyvm Gitian-lucid-i386 --natpf1 "guestssh,tcp,,2223,,22"
The final setup needed is to create an
ssh key that will be used to login to the virtual machine:
ssh-keygen -t dsa -f var/id_dsa -N "" ssh -p 2223 ubuntu@localhost 'mkdir -p .ssh && chmod 700 .ssh && cat >> .ssh/authorized_keys' < var/id_dsa.pub
Then log into the vm and copy the
ssh keys to root's
ssh -p 2223 ubuntu@localhost # Now in the vm sudo bash mkdir -p .ssh && chmod 700 .ssh && cat ~ubuntu/.ssh/authorized_keys >> .ssh/authorized_keys
USE_VBOX environment variable to use
VBOX instead of
If you have everything set-up properly, you should be able to:
PATH=$PATH:$(pwd)/libexec make-clean-vm --suite lucid --arch i386 # For LXC: LXC_ARCH=i386 LXC_SUITE=lucid on-target ls -la # For KVM: start-target 32 lucid-i386 & # wait a few seconds foro VM to start on-target ls -la stop-target
Copy any additional build inputs into a directory named inputs.
Then execute the build using a
YAML description file (can be run as non-root):
export USE_LXC=1 # LXC only bin/gbuild <package>.yml
or if you need to specify a commit for one of the git remotes:
bin/gbuild --commit <dir>=<hash> <package>.yml
The resulting report will appear in
To sign the result, perform:
bin/gsign --signer <signer> --release <release-name> <package>.yml
<signer> is your signing PGP key ID and
<release-name> is the name for the current release. This will put the result and signature in the
sigs/<package> directory can be managed through git to coordinate multiple signers.
After you've merged everybody's signatures, verify them:
bin/gverify --release <release-name> <package>.yml
- Log files are captured to the var directory
- You can run the utilities in libexec by running
- To start the target VM run
start-target 32 lucid-i386or
start-target 64 lucid-amd64
- To ssh into the target run
on-target -u root
- On the target, the build directory contains the code as it is compiled and install contains intermediate libraries
- By convention, the script in
<package>.ymlstarts with any environment setup you would need to manually compile things on the target
- disable sudo in target, just in case of a hypervisor exploit
- tar and other archive timestamp setter
lxc-start, which may require root. If you are in the admin group, you can add the following sudoers line to prevent asking for the password every time:
%admin ALL=NOPASSWD: /usr/bin/lxc-start
Recent distributions allow lxc-start to be run by non-priviledged users, so you might be able to rip-out the
sudo calls in
If you have a runaway
lxc-start command, just use
kill -9 on it.
The machine configuration requires access to br0 and assumes that the host address is
sudo brctl addbr br0 sudo ifconfig br0 10.0.2.2/24 up
Not very extensive, currently.
python -m unittest discover test