README: Link auto-upgrade-with-pinch

[pinch] / pinch.py

diff --git a/pinch.py b/pinch.py
index 79622f471d09f8dcadc96c8e10e8c5ddbb013db2..9e80c01436aa2071501be22e3048f70473ef4aad 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -1,3 +1,10 @@
+# pinch: PIN CHannels - a replacement for `nix-channel --update`
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, version 3.
+
+

 import argparse
 import configparser
 import filecmp
 import argparse
 import configparser
 import filecmp


@@ -64,7 +71,7 @@ class Verification:
 
     @staticmethod
     def _color(s: str, c: int) -> str:
 
     @staticmethod
     def _color(s: str, c: int) -> str:

-        return '\033[%2dm%s\033[00m' % (c, s)
+        return f'\033[{c:2d}m{s}\033[00m'

 
     def result(self, r: bool) -> None:
         message, color = {True: ('OK ', 92), False: ('FAIL', 91)}[r]
 
     def result(self, r: bool) -> None:
         message, color = {True: ('OK ', 92), False: ('FAIL', 91)}[r]


@@ -141,7 +148,6 @@ def symlink_archive(v: Verification, path: str) -> str:
 class AliasSearchPath(NamedTuple):
     alias_of: str
 
 class AliasSearchPath(NamedTuple):
     alias_of: str
 

-    # pylint: disable=no-self-use

     def pin(self, _: Verification, __: Optional[Pin]) -> AliasPin:
         return AliasPin()
 
     def pin(self, _: Verification, __: Optional[Pin]) -> AliasPin:
         return AliasPin()
 


@@ -149,7 +155,6 @@ class AliasSearchPath(NamedTuple):
 class SymlinkSearchPath(NamedTuple):
     path: str
 
 class SymlinkSearchPath(NamedTuple):
     path: str
 

-    # pylint: disable=no-self-use

     def pin(self, _: Verification, __: Optional[Pin]) -> SymlinkPin:
         return SymlinkPin()
 
     def pin(self, _: Verification, __: Optional[Pin]) -> SymlinkPin:
         return SymlinkPin()
 


@@ -202,7 +207,6 @@ class ChannelSearchPath(NamedTuple):
             tarball_sha256=table['nixexprs.tar.xz'].digest,
             git_revision=new_gitpin.git_revision)
 
             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)
 
     def fetch(self, v: Verification, pin: Pin) -> str:
         assert isinstance(pin, ChannelPin)
 


@@ -247,7 +251,7 @@ def compare(a: str, b: str) -> Tuple[List[str], List[str], List[str]]:
 
 def fetch_channel(
         v: Verification, channel: ChannelSearchPath) -> Tuple[str, str]:
 
 def fetch_channel(
         v: Verification, channel: ChannelSearchPath) -> Tuple[str, str]:

-    v.status('Fetching channel from %s' % channel.channel_url)
+    v.status(f'Fetching channel from {channel.channel_url}')

     with urllib.request.urlopen(channel.channel_url, timeout=10) as request:
         channel_html = request.read().decode()
         forwarded_url = request.geturl()
     with urllib.request.urlopen(channel.channel_url, timeout=10) as request:
         channel_html = request.read().decode()
         forwarded_url = request.geturl()


@@ -262,15 +266,29 @@ def parse_channel(v: Verification, channel_html: str) \
     d = xml.dom.minidom.parseString(channel_html)
     v.ok()
 
     d = xml.dom.minidom.parseString(channel_html)
     v.ok()
 

-    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)
-
-    v.status('Extracting git commit:')
+    v.status('Finding release name (1)')
+    title = d.getElementsByTagName('title')[0].firstChild
+    v.result(isinstance(title, xml.dom.minidom.CharacterData))
+    assert isinstance(title, xml.dom.minidom.CharacterData)
+    release_name = title.nodeValue.split()[2]
+    v.status('Finding release name (2)')
+    h1 = d.getElementsByTagName('h1')[0].firstChild
+    v.result(isinstance(h1, xml.dom.minidom.CharacterData))
+    assert isinstance(h1, xml.dom.minidom.CharacterData)
+    v.status('Verifying release name:')
+    v.status(release_name)
+    v.result(release_name == h1.nodeValue.split()[2])
+
+    v.status('Finding git commit')

     git_commit_node = d.getElementsByTagName('tt')[0]
     git_commit_node = d.getElementsByTagName('tt')[0]

+    v.result(
+        isinstance(
+            git_commit_node.firstChild,
+            xml.dom.minidom.CharacterData))
+    assert isinstance(
+        git_commit_node.firstChild,
+        xml.dom.minidom.CharacterData)
+    v.status('Extracting git commit:')

     git_revision = git_commit_node.firstChild.nodeValue
     v.status(git_revision)
     v.ok()
     git_revision = git_commit_node.firstChild.nodeValue
     v.status(git_revision)
     v.ok()


@@ -286,7 +304,7 @@ def parse_channel(v: Verification, channel_html: str) \
         digest = Digest16(row.childNodes[2].firstChild.firstChild.nodeValue)
         table[name] = ChannelTableEntry(url=url, digest=digest, size=size)
     v.ok()
         digest = Digest16(row.childNodes[2].firstChild.firstChild.nodeValue)
         table[name] = ChannelTableEntry(url=url, digest=digest, size=size)
     v.ok()

-    return table, GitPin(release_name=title_name, git_revision=git_revision)
+    return table, GitPin(release_name=release_name, git_revision=git_revision)

 
 
 def digest_string(s: bytes) -> Digest16:
 
 
 def digest_string(s: bytes) -> Digest16:


@@ -343,7 +361,7 @@ def fetch_with_nix_prefetch_url(
         v: Verification,
         url: str,
         digest: Digest16) -> str:
         v: Verification,
         url: str,
         digest: Digest16) -> str:

-    v.status('Fetching %s' % url)
+    v.status(f'Fetching {url}')

     process = subprocess.run(
         ['nix-prefetch-url', '--print-path', url, digest], stdout=subprocess.PIPE)
     v.result(process.returncode == 0)
     process = subprocess.run(
         ['nix-prefetch-url', '--print-path', url, digest], stdout=subprocess.PIPE)
     v.result(process.returncode == 0)


@@ -351,7 +369,7 @@ def fetch_with_nix_prefetch_url(
     assert empty == ''
     v.check("Verifying nix-prefetch-url's digest",
             to_Digest16(v, Digest32(prefetch_digest)) == digest)
     assert empty == ''
     v.check("Verifying nix-prefetch-url's digest",
             to_Digest16(v, Digest32(prefetch_digest)) == digest)

-    v.status("Verifying digest of %s" % path)
+    v.status(f"Verifying digest of {path}")

     file_digest = digest_file(path)
     v.result(file_digest == digest)
     return path  # type: ignore  # (for old mypy)
     file_digest = digest_file(path)
     v.result(file_digest == digest)
     return path  # type: ignore  # (for old mypy)


@@ -376,10 +394,7 @@ def tarball_cache_file(channel: TarrableSearchPath, pin: GitPin) -> str:
     return os.path.join(
         xdg.XDG_CACHE_HOME,
         'pinch/git-tarball',
     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))
+        f'{digest_string(channel.git_repo.encode())}-{pin.git_revision}-{pin.release_name}')

 
 
 def verify_git_ancestry(
 
 
 def verify_git_ancestry(


@@ -388,7 +403,7 @@ def verify_git_ancestry(
         old_revision: str,
         new_revision: str) -> None:
     cachedir = git_cache.git_cachedir(channel.git_repo)
         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)
+    v.status(f'Verifying rev is an ancestor of previous rev {old_revision}')

     process = subprocess.run(['git',
                               '-C',
                               cachedir,
     process = subprocess.run(['git',
                               '-C',
                               cachedir,


@@ -399,44 +414,55 @@ def verify_git_ancestry(
     v.result(process.returncode == 0)
 
 
     v.result(process.returncode == 0)
 
 

+def broken_symlinks_are_identical(root1: str, root2: str, path: str) -> bool:
+    a = os.path.join(root1, path)
+    b = os.path.join(root2, path)
+    return (os.path.islink(a)
+            and os.path.islink(b)
+            and not os.path.exists(a)
+            and not os.path.exists(b)
+            and os.readlink(a) == os.readlink(b))
+
+

 def compare_tarball_and_git(
         v: Verification,
         pin: GitPin,
         channel_contents: str,
         git_contents: str) -> None:
     v.status('Comparing channel tarball with git checkout')
 def compare_tarball_and_git(
         v: Verification,
         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, pin.release_name), git_contents)
+    tarball_contents = os.path.join(channel_contents, pin.release_name)
+    match, mismatch, errors = compare(tarball_contents, git_contents)

     v.ok()
     v.ok()

-    v.check('%d files match' % len(match), len(match) > 0)
-    v.check('%d files differ' % len(mismatch), len(mismatch) == 0)
+    v.check(f'{len(match)} files match', len(match) > 0)
+    v.check(f'{len(mismatch)} files differ', len(mismatch) == 0)

     expected_errors = [
         '.git-revision',
         '.version-suffix',
         'nixpkgs',
         'programs.sqlite',
         'svn-revision']
     expected_errors = [
         '.git-revision',
         '.version-suffix',
         'nixpkgs',
         'programs.sqlite',
         'svn-revision']

-    benign_errors = []
+    benign_expected_errors = []

     for ee in expected_errors:
         if ee in errors:
             errors.remove(ee)
     for ee in expected_errors:
         if ee in errors:
             errors.remove(ee)

-            benign_errors.append(ee)
+            benign_expected_errors.append(ee)
+    errors = [
+        e for e in errors
+        if not broken_symlinks_are_identical(tarball_contents, git_contents, e)
+    ]

     v.check(
     v.check(

-        '%d unexpected incomparable files' %
-        len(errors),
+        f'{len(errors)} unexpected incomparable files: {errors}',

         len(errors) == 0)
     v.check(
         len(errors) == 0)
     v.check(

-        '(%d of %d expected incomparable files)' %
-        (len(benign_errors),
-         len(expected_errors)),
-        len(benign_errors) == len(expected_errors))
+        f'({len(benign_expected_errors)} of {len(expected_errors)} expected incomparable files)',
+        len(benign_expected_errors) == len(expected_errors))

 
 
 def extract_tarball(
         v: Verification,
         table: Dict[str, ChannelTableEntry],
         dest: str) -> None:
 
 
 def extract_tarball(
         v: Verification,
         table: Dict[str, ChannelTableEntry],
         dest: str) -> None:

-    v.status('Extracting tarball %s' % table['nixexprs.tar.xz'].file)
+    v.status(f"Extracting tarball {table['nixexprs.tar.xz'].file}")

     shutil.unpack_archive(table['nixexprs.tar.xz'].file, dest)
     v.ok()
 
     shutil.unpack_archive(table['nixexprs.tar.xz'].file, dest)
     v.ok()
 


@@ -473,12 +499,10 @@ def git_get_tarball(
         output_filename = os.path.join(
             output_dir, pin.release_name + '.tar.xz')
         with open(output_filename, 'w', encoding='utf-8') as output_file:
         output_filename = os.path.join(
             output_dir, pin.release_name + '.tar.xz')
         with open(output_filename, 'w', encoding='utf-8') as output_file:

-            v.status(
-                'Generating tarball for git revision %s' %
-                pin.git_revision)
+            v.status(f'Generating tarball for git revision {pin.git_revision}')

             with subprocess.Popen(
                     ['git', '-C', git_cache.git_cachedir(channel.git_repo),
             with subprocess.Popen(
                     ['git', '-C', git_cache.git_cachedir(channel.git_repo),

-                        'archive', '--prefix=%s/' % pin.release_name, pin.git_revision],
+                        'archive', f'--prefix={pin.release_name}/', pin.git_revision],

                     stdout=subprocess.PIPE) as git:
                 with subprocess.Popen(['xz'], stdin=git.stdout, stdout=output_file) as xz:
                     xz.wait()
                     stdout=subprocess.PIPE) as git:
                 with subprocess.Popen(['xz'], stdin=git.stdout, stdout=output_file) as xz:
                     xz.wait()


@@ -503,8 +527,7 @@ def check_channel_metadata(
         v.result(f.read(999) == pin.git_revision)
 
     v.status(
         v.result(f.read(999) == pin.git_revision)
 
     v.status(

-        'Verifying version-suffix is a suffix of release name %s:' %
-        pin.release_name)
+        f'Verifying version-suffix is a suffix of release name {pin.release_name}:')

     with open(os.path.join(channel_contents, pin.release_name, '.version-suffix'),
               encoding='utf-8') as f:
         version_suffix = f.read(999)
     with open(os.path.join(channel_contents, pin.release_name, '.version-suffix'),
               encoding='utf-8') as f:
         version_suffix = f.read(999)


@@ -547,8 +570,7 @@ def git_revision_name(
                               git_revision],
                              stdout=subprocess.PIPE)
     v.result(process.returncode == 0 and process.stdout != b'')
                               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())
+    return f'{os.path.basename(channel.git_repo)}-{process.stdout.decode().strip()}'

 
 
 K = TypeVar('K')
 
 
 K = TypeVar('K')


@@ -584,7 +606,7 @@ def read_config_section(
     _, 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
     _, 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_present = pin_fields or P._fields == ()

     pin = P(**pin_fields) if pin_present else None  # type: ignore
     return SP(**remaining_fields), pin
 
     pin = P(**pin_fields) if pin_present else None  # type: ignore
     return SP(**remaining_fields), pin
 


@@ -593,9 +615,8 @@ def read_pinned_config_section(
         section: str, conf: configparser.SectionProxy) -> Tuple[SearchPath, Pin]:
     sp, pin = read_config_section(conf)
     if pin is None:
         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)
+        raise RuntimeError(
+            f'Cannot update unpinned channel "{section}" (Run "pin" before "update")')

     return sp, pin
 
 
     return sp, pin
 
 


@@ -613,7 +634,7 @@ def read_config_files(
         config = read_config(file)
         for section in config.sections():
             if section in merged_config:
         config = read_config(file)
         for section in config.sections():
             if section in merged_config:

-                raise Exception('Duplicate channel "%s"' % section)
+                raise RuntimeError('Duplicate channel "{section}"')

             merged_config[section] = config[section]
     return merged_config
 
             merged_config[section] = config[section]
     return merged_config
 


@@ -652,11 +673,11 @@ def updateCommand(args: argparse.Namespace) -> None:
         assert not isinstance(sp, AliasSearchPath)  # mypy can't see through
         assert not isinstance(pin, AliasPin)        # partition_dict()
         tarball = sp.fetch(v, pin)
         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)])
+        search_paths.extend(
+            ["-I", f"pinch_tarball_for_{pin.release_name}={tarball}"])

         exprs[section] = (
         exprs[section] = (

-            'f: f { name = "%s"; channelName = "%%s"; src = builtins.storePath "%s"; }' %
-            (pin.release_name, tarball))
+            f'f: f {{ name = "{pin.release_name}"; channelName = "%s"; '
+            f'src = builtins.storePath "{tarball}"; }}')

 
     for section, (sp, pin) in alias.items():
         assert isinstance(sp, AliasSearchPath)  # For mypy
 
     for section, (sp, pin) in alias.items():
         assert isinstance(sp, AliasSearchPath)  # For mypy


@@ -691,7 +712,7 @@ def main() -> None:
     parser_update = subparsers.add_parser('update')
     parser_update.add_argument('--dry-run', action='store_true')
     parser_update.add_argument('--profile', default=(
     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()))
+        f'/nix/var/nix/profiles/per-user/{getpass.getuser()}/channels'))

     parser_update.add_argument('channels_file', type=str, nargs='+')
     parser_update.set_defaults(func=updateCommand)
     args = parser.parse_args()
     parser_update.add_argument('channels_file', type=str, nargs='+')
     parser_update.set_defaults(func=updateCommand)
     args = parser.parse_args()