X-Git-Url: http://git.scottworley.com/pinch/blobdiff_plain/f9cd7bdc50fad6c24ac226a6532ecfb81d78cbe2..3b2117a3ff0c74c8cf3dc27bbe9a3105428d03d5:/pinch.py?ds=sidebyside diff --git a/pinch.py b/pinch.py index c77d891..f95323f 100644 --- a/pinch.py +++ b/pinch.py @@ -1,11 +1,17 @@ +import argparse +import configparser import filecmp import functools +import getpass import hashlib import operator import os import os.path +import shlex import shutil import subprocess +import sys +import tarfile import tempfile import types import urllib.parse @@ -13,34 +19,34 @@ import urllib.request import xml.dom.minidom from typing import ( + Callable, Dict, Iterable, List, + Mapping, + NamedTuple, NewType, + Optional, + Set, Tuple, + Type, + TypeVar, + Union, ) -Digest16 = NewType('Digest16', str) -Digest32 = NewType('Digest32', str) +import git_cache +# Use xdg module when it's less painful to have as a dependency -class ChannelTableEntry(types.SimpleNamespace): - digest: Digest16 - file: str - size: int - url: str +class XDG(NamedTuple): + XDG_CACHE_HOME: 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 + +xdg = XDG( + XDG_CACHE_HOME=os.getenv( + 'XDG_CACHE_HOME', + os.path.expanduser('~/.cache'))) class VerificationError(Exception): @@ -53,7 +59,7 @@ class Verification: self.line_length = 0 def status(self, s: str) -> None: - print(s, end=' ', flush=True) + print(s, end=' ', file=sys.stderr, flush=True) self.line_length += 1 + len(s) # Unicode?? @staticmethod @@ -63,9 +69,9 @@ class Verification: def result(self, r: bool) -> None: message, color = {True: ('OK ', 92), False: ('FAIL', 91)}[r] length = len(message) - cols = shutil.get_terminal_size().columns + cols = shutil.get_terminal_size().columns or 80 pad = (cols - (self.line_length + length)) % cols - print(' ' * pad + self._color(message, color)) + print(' ' * pad + self._color(message, color), file=sys.stderr) self.line_length = 0 if not r: raise VerificationError() @@ -78,6 +84,139 @@ class Verification: self.result(True) +Digest16 = NewType('Digest16', str) +Digest32 = NewType('Digest32', str) + + +class ChannelTableEntry(types.SimpleNamespace): + absolute_url: str + digest: Digest16 + file: str + size: int + url: str + + +class AliasPin(NamedTuple): + pass + + +class SymlinkPin(NamedTuple): + @property + def release_name(self) -> str: + return 'link' + + +class GitPin(NamedTuple): + git_revision: str + release_name: str + + +class ChannelPin(NamedTuple): + git_revision: str + release_name: str + tarball_url: str + tarball_sha256: str + + +Pin = Union[AliasPin, SymlinkPin, GitPin, ChannelPin] + + +def copy_to_nix_store(v: Verification, filename: str) -> str: + v.status('Putting tarball in Nix store') + process = subprocess.run( + ['nix-store', '--add', filename], stdout=subprocess.PIPE) + v.result(process.returncode == 0) + return process.stdout.decode().strip() # type: ignore # (for old mypy) + + +def symlink_archive(v: Verification, path: str) -> str: + with tempfile.TemporaryDirectory() as td: + archive_filename = os.path.join(td, 'link.tar.gz') + os.symlink(path, os.path.join(td, 'link')) + with tarfile.open(archive_filename, mode='x:gz') as t: + t.add(os.path.join(td, 'link'), arcname='link') + return copy_to_nix_store(v, archive_filename) + + +class AliasSearchPath(NamedTuple): + alias_of: str + + # pylint: disable=no-self-use + def pin(self, _: Verification, __: Optional[Pin]) -> AliasPin: + return AliasPin() + + +class SymlinkSearchPath(NamedTuple): + path: str + + # pylint: disable=no-self-use + def pin(self, _: Verification, __: Optional[Pin]) -> SymlinkPin: + return SymlinkPin() + + def fetch(self, v: Verification, _: Pin) -> str: + return symlink_archive(v, self.path) + + +class GitSearchPath(NamedTuple): + git_ref: str + git_repo: str + + def pin(self, v: Verification, old_pin: Optional[Pin]) -> GitPin: + _, new_revision = git_cache.fetch(self.git_repo, self.git_ref) + if old_pin is not None: + assert isinstance(old_pin, GitPin) + verify_git_ancestry(v, self, old_pin.git_revision, new_revision) + return GitPin(release_name=git_revision_name(v, self, new_revision), + git_revision=new_revision) + + def fetch(self, v: Verification, pin: Pin) -> str: + assert isinstance(pin, GitPin) + git_cache.ensure_rev_available( + self.git_repo, self.git_ref, pin.git_revision) + return git_get_tarball(v, self, pin) + + +class ChannelSearchPath(NamedTuple): + channel_url: str + git_ref: str + git_repo: str + + def pin(self, v: Verification, old_pin: Optional[Pin]) -> ChannelPin: + if old_pin is not None: + assert isinstance(old_pin, ChannelPin) + + channel_html, forwarded_url = fetch_channel(v, self) + table, new_gitpin = parse_channel(v, channel_html) + if old_pin is not None and old_pin.git_revision == new_gitpin.git_revision: + return old_pin + fetch_resources(v, new_gitpin, forwarded_url, table) + git_cache.ensure_rev_available( + self.git_repo, self.git_ref, new_gitpin.git_revision) + if old_pin is not None: + verify_git_ancestry( + v, self, old_pin.git_revision, new_gitpin.git_revision) + check_channel_contents(v, self, table, new_gitpin) + return ChannelPin( + release_name=new_gitpin.release_name, + tarball_url=table['nixexprs.tar.xz'].absolute_url, + tarball_sha256=table['nixexprs.tar.xz'].digest, + git_revision=new_gitpin.git_revision) + + # pylint: disable=no-self-use + def fetch(self, v: Verification, pin: Pin) -> str: + assert isinstance(pin, ChannelPin) + + return fetch_with_nix_prefetch_url( + v, pin.tarball_url, Digest16(pin.tarball_sha256)) + + +SearchPath = Union[AliasSearchPath, + SymlinkSearchPath, + GitSearchPath, + ChannelSearchPath] +TarrableSearchPath = Union[GitSearchPath, ChannelSearchPath] + + def compare(a: str, b: str) -> Tuple[List[str], List[str], List[str]]: def throw(error: OSError) -> None: @@ -106,18 +245,21 @@ def compare(a: str, b: str) -> Tuple[List[str], List[str], List[str]]: return filecmp.cmpfiles(a, b, files, shallow=False) -def fetch(v: Verification, channel: Channel) -> None: - v.status('Fetching channel') - 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', channel.url != channel.forwarded_url) +def fetch_channel( + v: Verification, channel: ChannelSearchPath) -> Tuple[str, str]: + v.status('Fetching channel from %s' % channel.channel_url) + request = urllib.request.urlopen(channel.channel_url, timeout=10) + channel_html = request.read().decode() + forwarded_url = request.geturl() + v.result(request.status == 200) # type: ignore # (for old mypy) + v.check('Got forwarded', channel.channel_url != forwarded_url) + return channel_html, forwarded_url -def parse_channel(v: Verification, channel: Channel) -> None: +def parse_channel(v: Verification, channel_html: str) \ + -> Tuple[Dict[str, ChannelTableEntry], GitPin]: v.status('Parsing channel description as XML') - d = xml.dom.minidom.parseString(channel.channel_html) + d = xml.dom.minidom.parseString(channel_html) v.ok() v.status('Extracting release name:') @@ -126,26 +268,25 @@ def parse_channel(v: Verification, channel: Channel) -> None: 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] - channel.git_commit = git_commit_node.firstChild.nodeValue - v.status(channel.git_commit) + git_revision = git_commit_node.firstChild.nodeValue + v.status(git_revision) v.ok() v.status('Verifying git commit label') v.result(git_commit_node.previousSibling.nodeValue == 'Git commit ') v.status('Parsing table') - channel.table = {} + table: Dict[str, ChannelTableEntry] = {} 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 = Digest16(row.childNodes[2].firstChild.firstChild.nodeValue) - channel.table[name] = ChannelTableEntry( - url=url, digest=digest, size=size) + table[name] = ChannelTableEntry(url=url, digest=digest, size=size) v.ok() + return table, GitPin(release_name=title_name, git_revision=git_revision) def digest_string(s: bytes) -> Digest16: @@ -161,18 +302,39 @@ def digest_file(filename: str) -> Digest16: return Digest16(hasher.hexdigest()) +@functools.lru_cache +def _experimental_flag_needed(v: Verification) -> bool: + v.status('Checking Nix version') + process = subprocess.run(['nix', '--help'], stdout=subprocess.PIPE) + v.result(process.returncode == 0) + return b'--experimental-features' in process.stdout + + +def _nix_command(v: Verification) -> List[str]: + return ['nix', '--experimental-features', + 'nix-command'] if _experimental_flag_needed(v) else ['nix'] + + 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) + process = subprocess.run(_nix_command(v) + [ + 'to-base16', + '--type', + 'sha256', + digest32], + stdout=subprocess.PIPE) 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) + process = subprocess.run(_nix_command(v) + [ + 'to-base32', + '--type', + 'sha256', + digest16], + stdout=subprocess.PIPE) v.result(process.returncode == 0) return Digest32(process.stdout.decode().strip()) @@ -183,91 +345,67 @@ def fetch_with_nix_prefetch_url( digest: Digest16) -> str: v.status('Fetching %s' % url) process = subprocess.run( - ['nix-prefetch-url', '--print-path', url, digest], capture_output=True) + ['nix-prefetch-url', '--print-path', url, digest], stdout=subprocess.PIPE) 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") + v.status("Verifying digest of %s" % path) file_digest = digest_file(path) v.result(file_digest == digest) - return path + return path # type: ignore # (for old mypy) -def fetch_resources(v: Verification, channel: Channel) -> None: +def fetch_resources( + v: Verification, + pin: GitPin, + forwarded_url: str, + table: Dict[str, ChannelTableEntry]) -> None: for resource in ['git-revision', 'nixexprs.tar.xz']: - fields = channel.table[resource] - url = urllib.parse.urljoin(channel.forwarded_url, fields.url) - fields.file = fetch_with_nix_prefetch_url(v, url, fields.digest) + fields = table[resource] + fields.absolute_url = urllib.parse.urljoin(forwarded_url, fields.url) + fields.file = fetch_with_nix_prefetch_url( + v, fields.absolute_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.result(open(table['git-revision'].file).read(999) == pin.git_revision) + + +def tarball_cache_file(channel: TarrableSearchPath, pin: GitPin) -> str: + return os.path.join( + xdg.XDG_CACHE_HOME, + 'pinch/git-tarball', + '%s-%s-%s' % + (digest_string(channel.git_repo.encode()), + pin.git_revision, + pin.release_name)) - 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') +def verify_git_ancestry( + v: Verification, + channel: TarrableSearchPath, + old_revision: str, + new_revision: str) -> None: + cachedir = git_cache.git_cachedir(channel.git_repo) + v.status('Verifying rev is an ancestor of previous rev %s' % old_revision) process = subprocess.run(['git', '-C', - channel.git_cachedir, + cachedir, 'merge-base', '--is-ancestor', - channel.git_commit, - channel.git_ref]) + old_revision, + new_revision]) v.result(process.returncode == 0) def compare_tarball_and_git( v: Verification, - channel: Channel, + pin: GitPin, 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) + channel_contents, pin.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) @@ -293,81 +431,279 @@ def compare_tarball_and_git( 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) +def extract_tarball( + v: Verification, + table: Dict[str, ChannelTableEntry], + dest: str) -> None: + v.status('Extracting tarball %s' % table['nixexprs.tar.xz'].file) + shutil.unpack_archive(table['nixexprs.tar.xz'].file, dest) v.ok() -def git_checkout(v: Verification, channel: Channel, dest: str) -> None: +def git_checkout( + v: Verification, + channel: TarrableSearchPath, + pin: GitPin, + dest: str) -> None: v.status('Checking out corresponding git revision') git = subprocess.Popen(['git', '-C', - channel.git_cachedir, + git_cache.git_cachedir(channel.git_repo), 'archive', - channel.git_commit], + pin.git_revision], stdout=subprocess.PIPE) tar = subprocess.Popen( ['tar', 'x', '-C', dest, '-f', '-'], stdin=git.stdout) - git.stdout.close() + if git.stdout: + git.stdout.close() tar.wait() git.wait() v.result(git.returncode == 0 and tar.returncode == 0) +def git_get_tarball( + v: Verification, + channel: TarrableSearchPath, + pin: GitPin) -> str: + cache_file = tarball_cache_file(channel, pin) + if os.path.exists(cache_file): + cached_tarball = open(cache_file).read(9999) + if os.path.exists(cached_tarball): + return cached_tarball + + with tempfile.TemporaryDirectory() as output_dir: + output_filename = os.path.join( + output_dir, pin.release_name + '.tar.xz') + with open(output_filename, 'w') as output_file: + v.status( + 'Generating tarball for git revision %s' % + pin.git_revision) + git = subprocess.Popen(['git', + '-C', + git_cache.git_cachedir(channel.git_repo), + 'archive', + '--prefix=%s/' % pin.release_name, + pin.git_revision], + stdout=subprocess.PIPE) + xz = subprocess.Popen(['xz'], stdin=git.stdout, stdout=output_file) + xz.wait() + git.wait() + v.result(git.returncode == 0 and xz.returncode == 0) + + store_tarball = copy_to_nix_store(v, output_filename) + + os.makedirs(os.path.dirname(cache_file), exist_ok=True) + open(cache_file, 'w').write(store_tarball) + return store_tarball # type: ignore # (for old mypy) + + def check_channel_metadata( v: Verification, - channel: Channel, + pin: GitPin, channel_contents: str) -> None: v.status('Verifying git commit in channel tarball') v.result( open( os.path.join( channel_contents, - channel.release_name, - '.git-revision')).read(999) == channel.git_commit) + pin.release_name, + '.git-revision')).read(999) == pin.git_revision) v.status( 'Verifying version-suffix is a suffix of release name %s:' % - channel.release_name) + pin.release_name) version_suffix = open( os.path.join( channel_contents, - channel.release_name, + pin.release_name, '.version-suffix')).read(999) v.status(version_suffix) - v.result(channel.release_name.endswith(version_suffix)) + v.result(pin.release_name.endswith(version_suffix)) -def check_channel_contents(v: Verification, channel: Channel) -> None: +def check_channel_contents( + v: Verification, + channel: TarrableSearchPath, + table: Dict[str, ChannelTableEntry], + pin: GitPin) -> None: with tempfile.TemporaryDirectory() as channel_contents, \ tempfile.TemporaryDirectory() as git_contents: - extract_tarball(v, channel, channel_contents) - check_channel_metadata(v, channel, channel_contents) + extract_tarball(v, table, channel_contents) + check_channel_metadata(v, pin, channel_contents) - git_checkout(v, channel, git_contents) + git_checkout(v, channel, pin, git_contents) - compare_tarball_and_git(v, channel, channel_contents, git_contents) + compare_tarball_and_git(v, pin, channel_contents, git_contents) v.status('Removing temporary directories') v.ok() -def main() -> None: +def git_revision_name( + v: Verification, + channel: TarrableSearchPath, + git_revision: str) -> str: + v.status('Getting commit date') + process = subprocess.run(['git', + '-C', + git_cache.git_cachedir(channel.git_repo), + 'log', + '-n1', + '--format=%ct-%h', + '--abbrev=11', + '--no-show-signature', + git_revision], + stdout=subprocess.PIPE) + v.result(process.returncode == 0 and process.stdout != b'') + return '%s-%s' % (os.path.basename(channel.git_repo), + process.stdout.decode().strip()) + + +K = TypeVar('K') +V = TypeVar('V') + + +def partition_dict(pred: Callable[[K, V], bool], + d: Dict[K, V]) -> Tuple[Dict[K, V], Dict[K, V]]: + selected: Dict[K, V] = {} + remaining: Dict[K, V] = {} + for k, v in d.items(): + if pred(k, v): + selected[k] = v + else: + remaining[k] = v + return selected, remaining + + +def filter_dict(d: Dict[K, V], fields: Set[K] + ) -> Tuple[Dict[K, V], Dict[K, V]]: + return partition_dict(lambda k, v: k in fields, d) + + +def read_config_section( + conf: configparser.SectionProxy) -> Tuple[SearchPath, Optional[Pin]]: + mapping: Mapping[str, Tuple[Type[SearchPath], Type[Pin]]] = { + 'alias': (AliasSearchPath, AliasPin), + 'channel': (ChannelSearchPath, ChannelPin), + 'git': (GitSearchPath, GitPin), + 'symlink': (SymlinkSearchPath, SymlinkPin), + } + SP, P = mapping[conf['type']] + _, all_fields = filter_dict(dict(conf.items()), set(['type'])) + pin_fields, remaining_fields = filter_dict(all_fields, set(P._fields)) + # Error suppression works around https://github.com/python/mypy/issues/9007 + pin_present = pin_fields != {} or P._fields == () + pin = P(**pin_fields) if pin_present else None # type: ignore + return SP(**remaining_fields), pin + + +def read_pinned_config_section( + section: str, conf: configparser.SectionProxy) -> Tuple[SearchPath, Pin]: + sp, pin = read_config_section(conf) + if pin is None: + raise Exception( + 'Cannot update unpinned channel "%s" (Run "pin" before "update")' % + section) + return sp, pin + + +def read_config(filename: str) -> configparser.ConfigParser: + config = configparser.ConfigParser() + config.read_file(open(filename), filename) + return config + + +def read_config_files( + filenames: Iterable[str]) -> Dict[str, configparser.SectionProxy]: + merged_config: Dict[str, configparser.SectionProxy] = {} + for file in filenames: + config = read_config(file) + for section in config.sections(): + if section in merged_config: + raise Exception('Duplicate channel "%s"' % section) + merged_config[section] = config[section] + return merged_config + + +def pinCommand(args: argparse.Namespace) -> None: + v = Verification() + config = read_config(args.channels_file) + for section in config.sections(): + if args.channels and section not in args.channels: + continue + + sp, old_pin = read_config_section(config[section]) + + config[section].update(sp.pin(v, old_pin)._asdict()) + + with open(args.channels_file, 'w') as configfile: + config.write(configfile) + + +def updateCommand(args: argparse.Namespace) -> None: v = Verification() - 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() + exprs: Dict[str, str] = {} + profile_manifest = os.path.join(args.profile, "manifest.nix") + search_paths: List[str] = [ + "-I", "pinch_profile=" + args.profile, + "-I", "pinch_profile_manifest=" + os.readlink(profile_manifest) + ] if os.path.exists(profile_manifest) else [] + config = { + section: read_pinned_config_section(section, conf) for section, + conf in read_config_files( + args.channels_file).items()} + alias, nonalias = partition_dict( + lambda k, v: isinstance(v[0], AliasSearchPath), config) + + for section, (sp, pin) in sorted(nonalias.items()): + assert not isinstance(sp, AliasSearchPath) # mypy can't see through + assert not isinstance(pin, AliasPin) # partition_dict() + tarball = sp.fetch(v, pin) + search_paths.extend(["-I", "pinch_tarball_for_%s=%s" % + (pin.release_name, tarball)]) + exprs[section] = ( + 'f: f { name = "%s"; channelName = "%%s"; src = builtins.storePath "%s"; }' % + (pin.release_name, tarball)) + + for section, (sp, pin) in alias.items(): + assert isinstance(sp, AliasSearchPath) # For mypy + exprs[section] = exprs[sp.alias_of] + + command = [ + 'nix-env', + '--profile', + args.profile, + '--show-trace', + '--file', + '', + '--install', + ] + search_paths + ['--from-expression'] + [ + exprs[name] % name for name in sorted(exprs.keys())] + if args.dry_run: + print(' '.join(map(shlex.quote, command))) + else: + v.status('Installing channels with nix-env') + process = subprocess.run(command) + v.result(process.returncode == 0) + + +def main() -> None: + parser = argparse.ArgumentParser(prog='pinch') + subparsers = parser.add_subparsers(dest='mode', required=True) + parser_pin = subparsers.add_parser('pin') + parser_pin.add_argument('channels_file', type=str) + parser_pin.add_argument('channels', type=str, nargs='*') + parser_pin.set_defaults(func=pinCommand) + parser_update = subparsers.add_parser('update') + parser_update.add_argument('--dry-run', action='store_true') + parser_update.add_argument('--profile', default=( + '/nix/var/nix/profiles/per-user/%s/channels' % getpass.getuser())) + parser_update.add_argument('channels_file', type=str, nargs='+') + parser_update.set_defaults(func=updateCommand) + args = parser.parse_args() + args.func(args) + + +if __name__ == '__main__': + main()