verify_release

#!/usr/bin/env python

# Copyright 2022, TUF contributors
# SPDX-License-Identifier: MIT OR Apache-2.0

"""verify_release - verify that published release matches a locally built one

Builds a release from current commit and verifies that the release artifacts
on GitHub and PyPI match the built release artifacts.
"""

import argparse
import json
import os
import subprocess
import sys
from filecmp import cmp
from tempfile import TemporaryDirectory
from typing import Optional

try:
    import build as _  # type: ignore[import-not-found] # noqa: F401
    import requests
except ImportError:
    print("Error: verify_release requires modules 'requests' and 'build':")
    print("    pip install requests build")
    sys.exit(1)

# Project variables
# Note that only these project artifacts are supported:
# [f"{PYPI_PROJECT}-{VER}-none-any.whl",  f"{PYPI_PROJECT}-{VER}.tar.gz"]
GITHUB_ORG = "theupdateframework"
GITHUB_PROJECT = "python-tuf"
PYPI_PROJECT = "tuf"

HTTP_TIMEOUT = 5


def build(build_dir: str) -> str:
    """Build release locally. Return version as string"""
    orig_dir = os.path.dirname(os.path.abspath(__file__))

    with TemporaryDirectory() as src_dir:
        # fresh git clone: this prevents uncommitted files from affecting build
        git_cmd = ["git", "clone", "--quiet", orig_dir, src_dir]
        subprocess.run(git_cmd, stdout=subprocess.DEVNULL, check=True)

        # patch env to constrain build backend version as we do in cd.yml
        env = os.environ.copy()
        env["PIP_CONSTRAINT"] = "requirements/build.txt"

        build_cmd = ["python3", "-m", "build", "--outdir", build_dir, src_dir]
        subprocess.run(
            build_cmd, stdout=subprocess.DEVNULL, check=True, env=env
        )

    for filename in os.listdir(build_dir):
        prefix, postfix = f"{PYPI_PROJECT}-", ".tar.gz"
        if filename.startswith(prefix) and filename.endswith(postfix):
            return filename[len(prefix) : -len(postfix)]

    raise RuntimeError("Build version not found")


def get_git_version() -> str:
    """Return version string from git describe"""
    cmd = ["git", "describe"]
    process = subprocess.run(cmd, text=True, capture_output=True, check=True)
    if not process.stdout.startswith("v") or not process.stdout.endswith("\n"):
        raise RuntimeError(f"Unexpected git version {process.stdout}")

    return process.stdout[1:-1]


def get_github_version() -> str:
    """Return version string of latest GitHub release"""
    release_json = f"https://api.github.com/repos/{GITHUB_ORG}/{GITHUB_PROJECT}/releases/latest"
    releases = json.loads(
        requests.get(release_json, timeout=HTTP_TIMEOUT).content
    )
    return releases["tag_name"][1:]


def get_pypi_pip_version() -> str:
    """Return latest version string available on PyPI according to pip"""
    # pip can't tell us what the newest available version is... So we download
    # newest tarball and figure out the version from the filename
    with TemporaryDirectory() as pypi_dir:
        cmd = ["pip", "download", "--no-deps", "--dest", pypi_dir]
        source_download = [*cmd, "--no-binary", PYPI_PROJECT, PYPI_PROJECT]
        subprocess.run(source_download, stdout=subprocess.DEVNULL, check=True)
        for filename in os.listdir(pypi_dir):
            prefix, postfix = f"{PYPI_PROJECT}-", ".tar.gz"
            if filename.startswith(prefix) and filename.endswith(postfix):
                return filename[len(prefix) : -len(postfix)]
        raise RuntimeError("PyPI version not found")


def verify_github_release(version: str, compare_dir: str) -> bool:
    """Verify that given GitHub version artifacts match expected artifacts"""
    base_url = (
        f"https://github.com/{GITHUB_ORG}/{GITHUB_PROJECT}/releases/download"
    )
    tar = f"{PYPI_PROJECT}-{version}.tar.gz"
    wheel = f"{PYPI_PROJECT}-{version}-py3-none-any.whl"
    with TemporaryDirectory() as github_dir:
        for filename in [tar, wheel]:
            url = f"{base_url}/v{version}/{filename}"
            response = requests.get(url, stream=True, timeout=HTTP_TIMEOUT)
            with open(os.path.join(github_dir, filename), "wb") as f:
                for data in response.iter_content():
                    f.write(data)

        return cmp(
            os.path.join(github_dir, tar),
            os.path.join(compare_dir, tar),
            shallow=False,
        ) and cmp(
            os.path.join(github_dir, wheel),
            os.path.join(compare_dir, wheel),
            shallow=False,
        )


def verify_pypi_release(version: str, compare_dir: str) -> bool:
    """Verify that given PyPI version artifacts match expected artifacts"""
    tar = f"{PYPI_PROJECT}-{version}.tar.gz"
    wheel = f"{PYPI_PROJECT}-{version}-py3-none-any.whl"

    with TemporaryDirectory() as pypi_dir:
        cmd = ["pip", "download", "--no-deps", "--dest", pypi_dir]
        target = f"{PYPI_PROJECT}=={version}"
        binary_download = [*cmd, target]
        source_download = [*cmd, "--no-binary", PYPI_PROJECT, target]

        subprocess.run(binary_download, stdout=subprocess.DEVNULL, check=True)
        subprocess.run(source_download, stdout=subprocess.DEVNULL, check=True)

        return cmp(
            os.path.join(pypi_dir, wheel),
            os.path.join(compare_dir, wheel),
            shallow=False,
        ) and cmp(
            os.path.join(pypi_dir, tar),
            os.path.join(compare_dir, tar),
            shallow=False,
        )


def sign_release_artifacts(
    version: str, build_dir: str, key_id: Optional[str] = None
) -> None:
    """Sign built release artifacts with gpg and write signature files to cwd"""
    sdist = f"{PYPI_PROJECT}-{version}.tar.gz"
    wheel = f"{PYPI_PROJECT}-{version}-py3-none-any.whl"
    cmd = ["gpg", "--detach-sign", "--armor"]

    if key_id is not None:
        cmd += ["--local-user", key_id]

    for filename in [sdist, wheel]:
        artifact_path = os.path.join(build_dir, filename)
        signature_path = f"{filename}.asc"
        subprocess.run(
            [*cmd, "--output", signature_path, artifact_path], check=True
        )

        if not os.path.exists(signature_path):
            raise RuntimeError("Signing failed, signature not found")


def finished(s: str) -> None:
    """Displays a finished message."""
    # clear line
    sys.stdout.write("\033[K")
    print(f"* {s}")


def progress(s: str) -> None:
    """Displays a progress message."""
    # clear line
    sys.stdout.write("\033[K")
    # carriage return but no newline: next print will overwrite this one
    print(f"  {s}...", end="\r", flush=True)


def main() -> int:  # noqa: D103
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--skip-pypi",
        action="store_true",
        dest="skip_pypi",
        help="Skip PyPI release check.",
    )
    parser.add_argument(
        "--sign",
        nargs="?",
        const=True,
        metavar="<key id>",
        dest="sign",
        help="Sign release artifacts with 'gpg'. If no <key id> is passed,"
        " the default signing key is used. Resulting '*.asc' files are written"
        " to CWD.",
    )
    args = parser.parse_args()

    success = True
    with TemporaryDirectory() as build_dir:
        progress("Building release")
        build_version = build(build_dir)
        finished(f"Built release {build_version}")

        git_version = get_git_version()
        if not git_version.startswith(build_version):
            raise RuntimeError(
                f"Git version is {git_version}, expected {build_version}"
            )
        if git_version != build_version:
            finished(f"WARNING: Git describes version as {git_version}")

        progress("Checking GitHub latest version")
        github_version = get_github_version()
        if github_version != build_version:
            finished(f"WARNING: GitHub latest version is {github_version}")

        if not args.skip_pypi:
            progress("Checking PyPI latest version")
            pypi_version = get_pypi_pip_version()
            if pypi_version != build_version:
                finished(f"WARNING: PyPI latest version is {pypi_version}")

            progress("Downloading release from PyPI")
            if not verify_pypi_release(build_version, build_dir):
                # This is expected while build is not reproducible
                finished("ERROR: PyPI artifacts do not match built release")
                success = False
            else:
                finished("PyPI artifacts match the built release")

        progress("Downloading release from GitHub")
        if not verify_github_release(build_version, build_dir):
            # This is expected while build is not reproducible
            finished("ERROR: GitHub artifacts do not match built release")
            success = False
        else:
            finished("GitHub artifacts match the built release")

        # NOTE: 'gpg' might prompt for password or ask if it should
        # override files...
        if args.sign:
            progress("Signing built release with gpg")
            if success:
                key_id = args.sign if args.sign is not True else None

                sign_release_artifacts(build_version, build_dir, key_id)
                finished("Created signatures in cwd (see '*.asc' files)")
            else:
                finished("WARNING: Skipped signing of non-matching artifacts")

    return 0 if success else 1


if __name__ == "__main__":
    sys.exit(main())