import os
import os.path
import shutil
+import subprocess
import tempfile
+import types
import urllib.parse
import urllib.request
import xml.dom.minidom
from typing import (
- Any,
Dict,
Iterable,
List,
- Sequence,
+ NewType,
Tuple,
)
+Digest16 = NewType('Digest16', str)
+Digest32 = NewType('Digest32', str)
+
+
+class ChannelTableEntry(types.SimpleNamespace):
+ digest: Digest16
+ file: str
+ size: int
+ url: str
+
+
+class Channel(types.SimpleNamespace):
+ channel_html: bytes
+ forwarded_url: str
+ git_cachedir: str
+ git_ref: str
+ git_repo: str
+ git_revision: str
+ release_name: str
+ table: Dict[str, ChannelTableEntry]
+ url: str
+
class VerificationError(Exception):
pass
self.result(True)
-def compare(a: str,
- b: str) -> Tuple[Sequence[str],
- Sequence[str],
- Sequence[str]]:
+def compare(a: str, b: str) -> Tuple[List[str], List[str], List[str]]:
def throw(error: OSError) -> None:
raise error
return filecmp.cmpfiles(a, b, files, shallow=False)
-def fetch(v: Verification, channel_url: str) -> Dict[str, Any]:
- info: Dict[str, Any] = {'url': channel_url}
+def fetch(v: Verification, channel: Channel) -> None:
v.status('Fetching channel')
- request = urllib.request.urlopen(
- 'https://channels.nixos.org/nixos-20.03', timeout=10)
- info['channel_html'] = request.read()
- info['forwarded_url'] = request.geturl()
+ request = urllib.request.urlopen(channel.url, timeout=10)
+ channel.channel_html = request.read()
+ channel.forwarded_url = request.geturl()
v.result(request.status == 200)
- v.check('Got forwarded', info['url'] != info['forwarded_url'])
- return info
+ v.check('Got forwarded', channel.url != channel.forwarded_url)
-def parse(v: Verification, info: Dict[str, Any]) -> None:
+def parse_channel(v: Verification, channel: Channel) -> None:
v.status('Parsing channel description as XML')
- d = xml.dom.minidom.parseString(info['channel_html'])
+ d = xml.dom.minidom.parseString(channel.channel_html)
v.ok()
- v.status('Extracting git commit')
+ v.status('Extracting release name:')
+ title_name = d.getElementsByTagName(
+ 'title')[0].firstChild.nodeValue.split()[2]
+ h1_name = d.getElementsByTagName('h1')[0].firstChild.nodeValue.split()[2]
+ v.status(title_name)
+ v.result(title_name == h1_name)
+ channel.release_name = title_name
+
+ v.status('Extracting git commit:')
git_commit_node = d.getElementsByTagName('tt')[0]
- info['git_commit'] = git_commit_node.firstChild.nodeValue
+ channel.git_commit = git_commit_node.firstChild.nodeValue
+ v.status(channel.git_commit)
v.ok()
v.status('Verifying git commit label')
v.result(git_commit_node.previousSibling.nodeValue == 'Git commit ')
v.status('Parsing table')
- info['table'] = {}
+ channel.table = {}
for row in d.getElementsByTagName('tr')[1:]:
name = row.childNodes[0].firstChild.firstChild.nodeValue
url = row.childNodes[0].firstChild.getAttribute('href')
size = int(row.childNodes[1].firstChild.nodeValue)
- digest = row.childNodes[2].firstChild.firstChild.nodeValue
- info['table'][name] = {'url': url, 'digest': digest, 'size': size}
+ digest = Digest16(row.childNodes[2].firstChild.firstChild.nodeValue)
+ channel.table[name] = ChannelTableEntry(
+ url=url, digest=digest, size=size)
v.ok()
-def fetch_resources(v: Verification, info: Dict[str, Any]) -> None:
+def digest_string(s: bytes) -> Digest16:
+ return Digest16(hashlib.sha256(s).hexdigest())
+
+
+def digest_file(filename: str) -> Digest16:
+ hasher = hashlib.sha256()
+ with open(filename, 'rb') as f:
+ # pylint: disable=cell-var-from-loop
+ for block in iter(lambda: f.read(4096), b''):
+ hasher.update(block)
+ return Digest16(hasher.hexdigest())
+
+
+def to_Digest16(v: Verification, digest32: Digest32) -> Digest16:
+ v.status('Converting digest to base16')
+ process = subprocess.run(
+ ['nix', 'to-base16', '--type', 'sha256', digest32], capture_output=True)
+ v.result(process.returncode == 0)
+ return Digest16(process.stdout.decode().strip())
+
+
+def to_Digest32(v: Verification, digest16: Digest16) -> Digest32:
+ v.status('Converting digest to base32')
+ process = subprocess.run(
+ ['nix', 'to-base32', '--type', 'sha256', digest16], capture_output=True)
+ v.result(process.returncode == 0)
+ return Digest32(process.stdout.decode().strip())
+
+def fetch_with_nix_prefetch_url(
+ v: Verification,
+ url: str,
+ digest: Digest16) -> str:
+ v.status('Fetching %s' % url)
+ process = subprocess.run(
+ ['nix-prefetch-url', '--print-path', url, digest], capture_output=True)
+ v.result(process.returncode == 0)
+ prefetch_digest, path, empty = process.stdout.decode().split('\n')
+ assert empty == ''
+ v.check("Verifying nix-prefetch-url's digest",
+ to_Digest16(v, Digest32(prefetch_digest)) == digest)
+ v.status("Verifying file digest")
+ file_digest = digest_file(path)
+ v.result(file_digest == digest)
+ return path
+
+
+def fetch_resources(v: Verification, channel: Channel) -> None:
for resource in ['git-revision', 'nixexprs.tar.xz']:
- fields = info['table'][resource]
- v.status('Fetching resource "%s"' % resource)
- url = urllib.parse.urljoin(info['forwarded_url'], fields['url'])
- request = urllib.request.urlopen(url, timeout=10)
- if fields['size'] < 4096:
- fields['content'] = request.read()
- else:
- with tempfile.NamedTemporaryFile(suffix='.nixexprs.tar.xz', delete=False) as tmp_file:
- shutil.copyfileobj(request, tmp_file)
- fields['file'] = tmp_file.name
- v.result(request.status == 200)
- v.status('Verifying digest for "%s"' % resource)
- if fields['size'] < 4096:
- actual_hash = hashlib.sha256(fields['content']).hexdigest()
- else:
- hasher = hashlib.sha256()
- with open(fields['file'], 'rb') as f:
- # pylint: disable=cell-var-from-loop
- for block in iter(lambda: f.read(4096), b''):
- hasher.update(block)
- actual_hash = hasher.hexdigest()
- v.result(actual_hash == fields['digest'])
- v.check('Verifying git commit on main page matches git commit in table',
- info['table']['git-revision']['content'].decode() == info['git_commit'])
-
-
-def extract_channel(v: Verification, info: Dict[str, Any]) -> None:
- with tempfile.TemporaryDirectory() as d:
- v.status('Extracting nixexprs.tar.xz')
- shutil.unpack_archive(info['table']['nixexprs.tar.xz']['file'], d)
- v.ok()
- v.status('Removing temporary directory')
+ fields = channel.table[resource]
+ url = urllib.parse.urljoin(channel.forwarded_url, fields.url)
+ fields.file = fetch_with_nix_prefetch_url(v, url, fields.digest)
+ v.status('Verifying git commit on main page matches git commit in table')
+ v.result(
+ open(
+ channel.table['git-revision'].file).read(999) == channel.git_commit)
+
+
+def git_fetch(v: Verification, channel: Channel) -> None:
+ # It would be nice if we could share the nix git cache, but as of the time
+ # of writing it is transitioning from gitv2 (deprecated) to gitv3 (not ready
+ # yet), and trying to straddle them both is too far into nix implementation
+ # details for my comfort. So we re-implement here half of nix.fetchGit.
+ # :(
+
+ # TODO: Consider using pyxdg to find this path.
+ channel.git_cachedir = os.path.expanduser(
+ '~/.cache/nix-pin-channel/git/%s' %
+ digest_string(
+ channel.url.encode()))
+ if not os.path.exists(channel.git_cachedir):
+ v.status("Initializing git repo")
+ process = subprocess.run(
+ ['git', 'init', '--bare', channel.git_cachedir])
+ v.result(process.returncode == 0)
+
+ v.status('Checking if we already have this rev:')
+ process = subprocess.run(
+ ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.git_commit])
+ if process.returncode == 0:
+ v.status('yes')
+ if process.returncode == 1:
+ v.status('no')
+ v.result(process.returncode == 0 or process.returncode == 1)
+ if process.returncode == 1:
+ v.status('Fetching ref "%s"' % channel.git_ref)
+ # We don't use --force here because we want to abort and freak out if forced
+ # updates are happening.
+ process = subprocess.run(['git',
+ '-C',
+ channel.git_cachedir,
+ 'fetch',
+ channel.git_repo,
+ '%s:%s' % (channel.git_ref,
+ channel.git_ref)])
+ v.result(process.returncode == 0)
+ v.status('Verifying that fetch retrieved this rev')
+ process = subprocess.run(
+ ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.git_commit])
+ v.result(process.returncode == 0)
+
+ v.status('Verifying rev is an ancestor of ref')
+ process = subprocess.run(['git',
+ '-C',
+ channel.git_cachedir,
+ 'merge-base',
+ '--is-ancestor',
+ channel.git_commit,
+ channel.git_ref])
+ v.result(process.returncode == 0)
+
+
+def compare_tarball_and_git(
+ v: Verification,
+ channel: Channel,
+ channel_contents: str,
+ git_contents: str) -> None:
+ v.status('Comparing channel tarball with git checkout')
+ match, mismatch, errors = compare(os.path.join(
+ channel_contents, channel.release_name), git_contents)
+ v.ok()
+ v.check('%d files match' % len(match), len(match) > 0)
+ v.check('%d files differ' % len(mismatch), len(mismatch) == 0)
+ expected_errors = [
+ '.git-revision',
+ '.version-suffix',
+ 'nixpkgs',
+ 'programs.sqlite',
+ 'svn-revision']
+ benign_errors = []
+ for ee in expected_errors:
+ if ee in errors:
+ errors.remove(ee)
+ benign_errors.append(ee)
+ v.check(
+ '%d unexpected incomparable files' %
+ len(errors),
+ len(errors) == 0)
+ v.check(
+ '(%d of %d expected incomparable files)' %
+ (len(benign_errors),
+ len(expected_errors)),
+ len(benign_errors) == len(expected_errors))
+
+
+def extract_tarball(v: Verification, channel: Channel, dest: str) -> None:
+ v.status('Extracting tarball %s' %
+ channel.table['nixexprs.tar.xz'].file)
+ shutil.unpack_archive(
+ channel.table['nixexprs.tar.xz'].file,
+ dest)
+ v.ok()
+
+
+def git_checkout(v: Verification, channel: Channel, dest: str) -> None:
+ v.status('Checking out corresponding git revision')
+ git = subprocess.Popen(['git',
+ '-C',
+ channel.git_cachedir,
+ 'archive',
+ channel.git_commit],
+ stdout=subprocess.PIPE)
+ tar = subprocess.Popen(
+ ['tar', 'x', '-C', dest, '-f', '-'], stdin=git.stdout)
+ git.stdout.close()
+ tar.wait()
+ git.wait()
+ v.result(git.returncode == 0 and tar.returncode == 0)
+
+
+def check_channel_contents(v: Verification, channel: Channel) -> None:
+ with tempfile.TemporaryDirectory() as channel_contents, \
+ tempfile.TemporaryDirectory() as git_contents:
+
+ extract_tarball(v, channel, channel_contents)
+ git_checkout(v, channel, git_contents)
+
+ compare_tarball_and_git(v, channel, channel_contents, git_contents)
+
+ v.status('Removing temporary directories')
v.ok()
def main() -> None:
v = Verification()
- info = fetch(v, 'https://channels.nixos.org/nixos-20.03')
- parse(v, info)
- fetch_resources(v, info)
- extract_channel(v, info)
- print(info)
+ channel = Channel(url='https://channels.nixos.org/nixos-20.03',
+ git_repo='https://github.com/NixOS/nixpkgs.git',
+ git_ref='nixos-20.03')
+ fetch(v, channel)
+ parse_channel(v, channel)
+ fetch_resources(v, channel)
+ git_fetch(v, channel)
+ check_channel_contents(v, channel)
+ print(channel)
main()
projects / pinch / blobdiff