nixpkgs/pkgs/build-support/rust/fetch-cargo-vendor-util.py
TomaSajt e14998cb44 rustPlatform.fetchCargoVendor: dereference symlinks from entire git tree
We accidentally broke the symlink dereferencing logic in https://github.com/NixOS/nixpkgs/pull/379049
After that PR, only symlinks inside the crate subtree got dereferened,
breaking packages which symlink files from a parent directory to the crate subtree

This commit adds a custom ignore function for copytree instead of relying on
ignore_dangling_symlinks=True
2025-04-03 20:09:31 +05:30

348 lines
12 KiB
Python

import functools
import hashlib
import json
import multiprocessing as mp
import re
import shutil
import subprocess
import sys
import tomllib
from os.path import islink, realpath
from pathlib import Path
from typing import Any, TypedDict, cast
from urllib.parse import unquote
import requests
from requests.adapters import HTTPAdapter, Retry
eprint = functools.partial(print, file=sys.stderr)
def load_toml(path: Path) -> dict[str, Any]:
with open(path, "rb") as f:
return tomllib.load(f)
def get_lockfile_version(cargo_lock_toml: dict[str, Any]) -> int:
# lockfile v1 and v2 don't have the `version` key, so assume v2
version = cargo_lock_toml.get("version", 2)
# TODO: add logic for differentiating between v1 and v2
return version
def create_http_session() -> requests.Session:
retries = Retry(
total=5,
backoff_factor=0.5,
status_forcelist=[500, 502, 503, 504]
)
session = requests.Session()
session.mount('http://', HTTPAdapter(max_retries=retries))
session.mount('https://', HTTPAdapter(max_retries=retries))
return session
def download_file_with_checksum(session: requests.Session, url: str, destination_path: Path) -> str:
sha256_hash = hashlib.sha256()
with session.get(url, stream=True) as response:
if not response.ok:
raise Exception(f"Failed to fetch file from {url}. Status code: {response.status_code}")
with open(destination_path, "wb") as file:
for chunk in response.iter_content(1024): # Download in chunks
if chunk: # Filter out keep-alive chunks
file.write(chunk)
sha256_hash.update(chunk)
# Compute the final checksum
checksum = sha256_hash.hexdigest()
return checksum
def get_download_url_for_tarball(pkg: dict[str, Any]) -> str:
# TODO: support other registries
# maybe fetch config.json from the registry root and get the dl key
# See: https://doc.rust-lang.org/cargo/reference/registry-index.html#index-configuration
if pkg["source"] != "registry+https://github.com/rust-lang/crates.io-index":
raise Exception("Only the default crates.io registry is supported.")
return f"https://crates.io/api/v1/crates/{pkg["name"]}/{pkg["version"]}/download"
def download_tarball(session: requests.Session, pkg: dict[str, Any], out_dir: Path) -> None:
url = get_download_url_for_tarball(pkg)
filename = f"{pkg["name"]}-{pkg["version"]}.tar.gz"
# TODO: allow legacy checksum specification, see importCargoLock for example
# also, don't forget about the other usage of the checksum
expected_checksum = pkg["checksum"]
tarball_out_dir = out_dir / "tarballs" / filename
eprint(f"Fetching {url} -> tarballs/{filename}")
calculated_checksum = download_file_with_checksum(session, url, tarball_out_dir)
if calculated_checksum != expected_checksum:
raise Exception(f"Hash mismatch! File fetched from {url} had checksum {calculated_checksum}, expected {expected_checksum}.")
def download_git_tree(url: str, git_sha_rev: str, out_dir: Path) -> None:
tree_out_dir = out_dir / "git" / git_sha_rev
eprint(f"Fetching {url}#{git_sha_rev} -> git/{git_sha_rev}")
cmd = ["nix-prefetch-git", "--builder", "--quiet", "--fetch-submodules", "--url", url, "--rev", git_sha_rev, "--out", str(tree_out_dir)]
subprocess.check_output(cmd)
GIT_SOURCE_REGEX = re.compile("git\\+(?P<url>[^?]+)(\\?(?P<type>rev|tag|branch)=(?P<value>.*))?#(?P<git_sha_rev>.*)")
class GitSourceInfo(TypedDict):
url: str
type: str | None
value: str | None
git_sha_rev: str
def parse_git_source(source: str, lockfile_version: int) -> GitSourceInfo:
match = GIT_SOURCE_REGEX.match(source)
if match is None:
raise Exception(f"Unable to process git source: {source}.")
source_info = cast(GitSourceInfo, match.groupdict(default=None))
# the source URL is URL-encoded in lockfile_version >=4
# since we just used regex to parse it we have to manually decode the escaped branch/tag name
if lockfile_version >= 4 and source_info["value"] is not None:
source_info["value"] = unquote(source_info["value"])
return source_info
def create_vendor_staging(lockfile_path: Path, out_dir: Path) -> None:
cargo_lock_toml = load_toml(lockfile_path)
lockfile_version = get_lockfile_version(cargo_lock_toml)
git_packages: list[dict[str, Any]] = []
registry_packages: list[dict[str, Any]] = []
for pkg in cargo_lock_toml["package"]:
# ignore local dependenices
if "source" not in pkg.keys():
eprint(f"Skipping local dependency: {pkg["name"]}")
continue
source = pkg["source"]
if source.startswith("git+"):
git_packages.append(pkg)
elif source.startswith("registry+"):
registry_packages.append(pkg)
else:
raise Exception(f"Can't process source: {source}.")
git_sha_rev_to_url: dict[str, str] = {}
for pkg in git_packages:
source_info = parse_git_source(pkg["source"], lockfile_version)
git_sha_rev_to_url[source_info["git_sha_rev"]] = source_info["url"]
out_dir.mkdir(exist_ok=True)
shutil.copy(lockfile_path, out_dir / "Cargo.lock")
# fetch git trees sequentially, since fetching concurrently leads to flaky behaviour
if len(git_packages) != 0:
(out_dir / "git").mkdir()
for git_sha_rev, url in git_sha_rev_to_url.items():
download_git_tree(url, git_sha_rev, out_dir)
# run tarball download jobs in parallel, with at most 5 concurrent download jobs
with mp.Pool(min(5, mp.cpu_count())) as pool:
if len(registry_packages) != 0:
(out_dir / "tarballs").mkdir()
session = create_http_session()
tarball_args_gen = ((session, pkg, out_dir) for pkg in registry_packages)
pool.starmap(download_tarball, tarball_args_gen)
def get_manifest_metadata(manifest_path: Path) -> dict[str, Any]:
cmd = ["cargo", "metadata", "--format-version", "1", "--no-deps", "--manifest-path", str(manifest_path)]
output = subprocess.check_output(cmd)
return json.loads(output)
def try_get_crate_manifest_path_from_mainfest_path(manifest_path: Path, crate_name: str) -> Path | None:
metadata = get_manifest_metadata(manifest_path)
for pkg in metadata["packages"]:
if pkg["name"] == crate_name:
return Path(pkg["manifest_path"])
return None
def find_crate_manifest_in_tree(tree: Path, crate_name: str) -> Path:
# in some cases Cargo.toml is not located at the top level, so we also look at subdirectories
manifest_paths = tree.glob("**/Cargo.toml")
for manifest_path in manifest_paths:
res = try_get_crate_manifest_path_from_mainfest_path(manifest_path, crate_name)
if res is not None:
return res
raise Exception(f"Couldn't find manifest for crate {crate_name} inside {tree}.")
def copy_and_patch_git_crate_subtree(git_tree: Path, crate_name: str, crate_out_dir: Path) -> None:
# This function will get called by copytree to decide which entries of a directory should be copied
# We'll copy everything except symlinks that are invalid
def ignore_func(dir_str: str, path_strs: list[str]) -> list[str]:
ignorelist: list[str] = []
dir = Path(realpath(dir_str, strict=True))
for path_str in path_strs:
path = dir / path_str
if not islink(path):
continue
# Filter out cyclic symlinks and symlinks pointing at nonexistant files
try:
target_path = Path(realpath(path, strict=True))
except OSError:
ignorelist.append(path_str)
eprint(f"Failed to resolve symlink, ignoring: {path}")
continue
# Filter out symlinks that point outside of the current crate's base git tree
# This can be useful if the nix build sandbox is turned off and there is a symlink to a common absolute path
if not target_path.is_relative_to(git_tree):
ignorelist.append(path_str)
eprint(f"Symlink points outside of the crate's base git tree, ignoring: {path} -> {target_path}")
continue
return ignorelist
crate_manifest_path = find_crate_manifest_in_tree(git_tree, crate_name)
crate_tree = crate_manifest_path.parent
eprint(f"Copying to {crate_out_dir}")
shutil.copytree(crate_tree, crate_out_dir, ignore=ignore_func)
crate_out_dir.chmod(0o755)
with open(crate_manifest_path, "r") as f:
manifest_data = f.read()
if "workspace" in manifest_data:
crate_manifest_metadata = get_manifest_metadata(crate_manifest_path)
workspace_root = Path(crate_manifest_metadata["workspace_root"])
root_manifest_path = workspace_root / "Cargo.toml"
manifest_path = crate_out_dir / "Cargo.toml"
manifest_path.chmod(0o644)
eprint(f"Patching {manifest_path}")
cmd = ["replace-workspace-values", str(manifest_path), str(root_manifest_path)]
subprocess.check_output(cmd)
def extract_crate_tarball_contents(tarball_path: Path, crate_out_dir: Path) -> None:
eprint(f"Unpacking to {crate_out_dir}")
crate_out_dir.mkdir()
cmd = ["tar", "xf", str(tarball_path), "-C", str(crate_out_dir), "--strip-components=1"]
subprocess.check_output(cmd)
def create_vendor(vendor_staging_dir: Path, out_dir: Path) -> None:
lockfile_path = vendor_staging_dir / "Cargo.lock"
out_dir.mkdir(exist_ok=True)
shutil.copy(lockfile_path, out_dir / "Cargo.lock")
cargo_lock_toml = load_toml(lockfile_path)
lockfile_version = get_lockfile_version(cargo_lock_toml)
config_lines = [
'[source.vendored-sources]',
'directory = "@vendor@"',
'[source.crates-io]',
'replace-with = "vendored-sources"',
]
seen_source_keys = set()
for pkg in cargo_lock_toml["package"]:
# ignore local dependenices
if "source" not in pkg.keys():
continue
source: str = pkg["source"]
dir_name = f"{pkg["name"]}-{pkg["version"]}"
crate_out_dir = out_dir / dir_name
if source.startswith("git+"):
source_info = parse_git_source(pkg["source"], lockfile_version)
git_sha_rev = source_info["git_sha_rev"]
git_tree = vendor_staging_dir / "git" / git_sha_rev
copy_and_patch_git_crate_subtree(git_tree, pkg["name"], crate_out_dir)
# git based crates allow having no checksum information
with open(crate_out_dir / ".cargo-checksum.json", "w") as f:
json.dump({"files": {}}, f)
source_key = source[0:source.find("#")]
if source_key in seen_source_keys:
continue
seen_source_keys.add(source_key)
config_lines.append(f'[source."{source_key}"]')
config_lines.append(f'git = "{source_info["url"]}"')
if source_info["type"] is not None:
config_lines.append(f'{source_info["type"]} = "{source_info["value"]}"')
config_lines.append('replace-with = "vendored-sources"')
elif source.startswith("registry+"):
filename = f"{pkg["name"]}-{pkg["version"]}.tar.gz"
tarball_path = vendor_staging_dir / "tarballs" / filename
extract_crate_tarball_contents(tarball_path, crate_out_dir)
# non-git based crates need the package checksum at minimum
with open(crate_out_dir / ".cargo-checksum.json", "w") as f:
json.dump({"files": {}, "package": pkg["checksum"]}, f)
else:
raise Exception(f"Can't process source: {source}.")
(out_dir / ".cargo").mkdir()
with open(out_dir / ".cargo" / "config.toml", "w") as config_file:
config_file.writelines(line + "\n" for line in config_lines)
def main() -> None:
subcommand = sys.argv[1]
subcommand_func_dict = {
"create-vendor-staging": lambda: create_vendor_staging(lockfile_path=Path(sys.argv[2]), out_dir=Path(sys.argv[3])),
"create-vendor": lambda: create_vendor(vendor_staging_dir=Path(sys.argv[2]), out_dir=Path(sys.argv[3]))
}
subcommand_func = subcommand_func_dict.get(subcommand)
if subcommand_func is None:
raise Exception(f"Unknown subcommand: '{subcommand}'. Must be one of {list(subcommand_func_dict.keys())}")
subcommand_func()
if __name__ == "__main__":
main()