proxygen
Easy builds for Facebook projects

This is a Python 2.6+ library designed to simplify continuous-integration (and other builds) of Facebook projects.

For external Travis builds, the entry point is travis_docker_build.sh.

Using Docker to reproduce a CI build

If you are debugging or enhancing a CI build, you will want to do so from host or virtual machine that can run a reasonably modern version of Docker:

1 ./make_docker_context.py --help # See available options for OS & compiler
2 # Tiny wrapper that starts a Travis-like build with compile caching:
3 os_image=ubuntu:16.04 \
4  gcc_version=5 \
5  make_parallelism=2 \
6  travis_cache_dir=~/travis_ccache \
7  ./travis_docker_build.sh &> build_at_$(date +'%Y%m%d_%H%M%S').log

IMPORTANT: Read fbcode_builder/README.docker before diving in!

Setting travis_cache_dir turns on ccache, saving a fresh copy of ccache.tgz after every build. This will invalidate Docker's layer cache, foring it to rebuild starting right after OS package setup, but the builds will be fast because all the compiles will be cached. To iterate without invalidating the Docker layer cache, just cd /tmp/docker-context-* and interact with the Dockerfile normally. Note that the docker-context-* dirs preserve a copy of ccache.tgz as they first used it.

What to read next

The *.py files are fairly well-documented. You might want to peruse them in this order:

  • shell_quoting.py
  • fbcode_builder.py
  • docker_builder.py
  • make_docker_context.py

As far as runs on Travis go, the control flow is:

  • .travis.yml calls
  • travis_docker_build.sh calls
  • docker_build_with_ccache.sh

This library also has an (unpublished) component targeting Facebook's internal continuous-integration platform using the same build-step DSL.

Contributing

Please follow the ambient style (or PEP-8), and keep the code Python 2.6 compatible – since fbcode_builder's only dependency is Docker, we want to allow building projects on even fairly ancient base systems. We also wish to be compatible with Python 3, and would appreciate it if you kept that in mind while making changes also.