python/pip_install/extract_wheels/extract_single_wheel.py

import argparse
import errno
import glob
import os
import subprocess
import sys
from tempfile import NamedTemporaryFile

from python.pip_install.extract_wheels import arguments, bazel, requirements
from python.pip_install.extract_wheels.annotation import annotation_from_str_path


def configure_reproducible_wheels() -> None:
    """Modifies the environment to make wheel building reproducible.
    Wheels created from sdists are not reproducible by default. We can however workaround this by
    patching in some configuration with environment variables.
    """

    # wheel, by default, enables debug symbols in GCC. This incidentally captures the build path in the .so file
    # We can override this behavior by disabling debug symbols entirely.
    # https://github.com/pypa/pip/issues/6505
    if "CFLAGS" in os.environ:
        os.environ["CFLAGS"] += " -g0"
    else:
        os.environ["CFLAGS"] = "-g0"

    # set SOURCE_DATE_EPOCH to 1980 so that we can use python wheels
    # https://github.com/NixOS/nixpkgs/blob/master/doc/languages-frameworks/python.section.md#python-setuppy-bdist_wheel-cannot-create-whl
    if "SOURCE_DATE_EPOCH" not in os.environ:
        os.environ["SOURCE_DATE_EPOCH"] = "315532800"

    # Python wheel metadata files can be unstable.
    # See https://bitbucket.org/pypa/wheel/pull-requests/74/make-the-output-of-metadata-files/diff
    if "PYTHONHASHSEED" not in os.environ:
        os.environ["PYTHONHASHSEED"] = "0"

def main() -> None:
    parser = argparse.ArgumentParser(
        description="Build and/or fetch a single wheel based on the requirement passed in"
    )
    parser.add_argument(
        "--requirement",
        action="store",
        required=True,
        help="A single PEP508 requirement specifier string.",
    )
    parser.add_argument(
        "--annotation",
        type=annotation_from_str_path,
        help="A json encoded file containing annotations for rendered packages.",
    )
    arguments.parse_common_args(parser)
    args = parser.parse_args()
    deserialized_args = dict(vars(args))
    arguments.deserialize_structured_args(deserialized_args)

    configure_reproducible_wheels()

    pip_args = (
        [sys.executable, "-m", "pip"]
        + (["--isolated"] if args.isolated else [])
        + ["download" if args.download_only else "wheel", "--no-deps"]
        + deserialized_args["extra_pip_args"]
    )

    requirement_file = NamedTemporaryFile(mode="wb", delete=False)
    try:
        requirement_file.write(args.requirement.encode("utf-8"))
        requirement_file.flush()
        # Close the file so pip is allowed to read it when running on Windows.
        # For more information, see: https://bugs.python.org/issue14243
        requirement_file.close()
        # Requirement specific args like --hash can only be passed in a requirements file,
        # so write our single requirement into a temp file in case it has any of those flags.
        pip_args.extend(["-r", requirement_file.name])

        env = os.environ.copy()
        env.update(deserialized_args["environment"])
        # Assumes any errors are logged by pip so do nothing. This command will fail if pip fails
        subprocess.run(pip_args, check=True, env=env)
    finally:
        try:
            os.unlink(requirement_file.name)
        except OSError as e:
            if e.errno != errno.ENOENT:
                raise

    name, extras_for_pkg = requirements._parse_requirement_for_extra(args.requirement)
    extras = {name: extras_for_pkg} if extras_for_pkg and name else dict()

    whl = next(iter(glob.glob("*.whl")))
    bazel.extract_wheel(
        wheel_file=whl,
        extras=extras,
        pip_data_exclude=deserialized_args["pip_data_exclude"],
        enable_implicit_namespace_pkgs=args.enable_implicit_namespace_pkgs,
        incremental=True,
        repo_prefix=args.repo_prefix,
        annotation=args.annotation,
    )


if __name__ == "__main__":
    main()