Don't require experimental-features=nix-command in system nix.conf

[pinch] / pinch.py

diff --git a/pinch.py b/pinch.py
index 125fa63a1949527b1ab9f1a4c84a330443da2ade..369dd56dea240ac44da5ddfa1e14e72ac9dcea7c 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -11,6 +11,7 @@ import shlex
 import shutil
 import subprocess
 import sys
 import shutil
 import subprocess
 import sys

+import tarfile

 import tempfile
 import types
 import urllib.parse
 import tempfile
 import types
 import urllib.parse


@@ -18,6 +19,7 @@ import urllib.request
 import xml.dom.minidom
 
 from typing import (
 import xml.dom.minidom
 
 from typing import (

+    Callable,

     Dict,
     Iterable,
     List,
     Dict,
     Iterable,
     List,


@@ -32,6 +34,8 @@ from typing import (
     Union,
 )
 
     Union,
 )
 

+import git_cache
+

 # Use xdg module when it's less painful to have as a dependency
 
 
 # Use xdg module when it's less painful to have as a dependency
 
 


@@ -96,6 +100,12 @@ class AliasPin(NamedTuple):
     pass
 
 
     pass
 
 

+class SymlinkPin(NamedTuple):
+    @property
+    def release_name(self) -> str:
+        return 'link'
+
+

 class GitPin(NamedTuple):
     git_revision: str
     release_name: str
 class GitPin(NamedTuple):
     git_revision: str
     release_name: str


@@ -108,7 +118,24 @@ class ChannelPin(NamedTuple):
     tarball_sha256: str
 
 
     tarball_sha256: str
 
 

-Pin = Union[AliasPin, GitPin, ChannelPin]
+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):
 
 
 class AliasSearchPath(NamedTuple):


@@ -119,22 +146,33 @@ class AliasSearchPath(NamedTuple):
         return 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:
 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)
         if old_pin is not None:
             assert isinstance(old_pin, GitPin)

-        old_revision = old_pin.git_revision if old_pin is not None else None
-
-        new_revision = git_fetch(v, self, None, old_revision)
+            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)
         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)

-        ensure_git_rev_available(v, self, pin, None)
+        git_cache.ensure_rev_available(
+            self.git_repo, self.git_ref, pin.git_revision)

         return git_get_tarball(v, self, pin)
 
 
         return git_get_tarball(v, self, pin)
 
 


@@ -146,12 +184,17 @@ class ChannelSearchPath(NamedTuple):
     def pin(self, v: Verification, old_pin: Optional[Pin]) -> ChannelPin:
         if old_pin is not None:
             assert isinstance(old_pin, ChannelPin)
     def pin(self, v: Verification, old_pin: Optional[Pin]) -> ChannelPin:
         if old_pin is not None:
             assert isinstance(old_pin, ChannelPin)

-        old_revision = old_pin.git_revision if old_pin is not None else None

 
         channel_html, forwarded_url = fetch_channel(v, self)
         table, new_gitpin = parse_channel(v, channel_html)
 
         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)
         fetch_resources(v, new_gitpin, forwarded_url, table)

-        ensure_git_rev_available(v, self, new_gitpin, old_revision)
+        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,
         check_channel_contents(v, self, table, new_gitpin)
         return ChannelPin(
             release_name=new_gitpin.release_name,


@@ -167,7 +210,10 @@ class ChannelSearchPath(NamedTuple):
             v, pin.tarball_url, Digest16(pin.tarball_sha256))
 
 
             v, pin.tarball_url, Digest16(pin.tarball_sha256))
 
 

-SearchPath = Union[AliasSearchPath, GitSearchPath, ChannelSearchPath]
+SearchPath = Union[AliasSearchPath,
+                   SymlinkSearchPath,
+                   GitSearchPath,
+                   ChannelSearchPath]

 TarrableSearchPath = Union[GitSearchPath, ChannelSearchPath]
 
 
 TarrableSearchPath = Union[GitSearchPath, ChannelSearchPath]
 
 


@@ -203,7 +249,7 @@ def fetch_channel(
         v: Verification, channel: ChannelSearchPath) -> Tuple[str, str]:
     v.status('Fetching channel')
     request = urllib.request.urlopen(channel.channel_url, timeout=10)
         v: Verification, channel: ChannelSearchPath) -> Tuple[str, str]:
     v.status('Fetching channel')
     request = urllib.request.urlopen(channel.channel_url, timeout=10)

-    channel_html = request.read()
+    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)
     forwarded_url = request.geturl()
     v.result(request.status == 200)  # type: ignore  # (for old mypy)
     v.check('Got forwarded', channel.channel_url != forwarded_url)


@@ -258,16 +304,28 @@ def digest_file(filename: str) -> Digest16:
 
 def to_Digest16(v: Verification, digest32: Digest32) -> Digest16:
     v.status('Converting digest to base16')
 
 def to_Digest16(v: Verification, digest32: Digest32) -> Digest16:
     v.status('Converting digest to base16')

-    process = subprocess.run(
-        ['nix', 'to-base16', '--type', 'sha256', digest32], stdout=subprocess.PIPE)
+    process = subprocess.run(['nix',
+                              '--experimental-features',
+                              'nix-command',
+                              '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')
     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], stdout=subprocess.PIPE)
+    process = subprocess.run(['nix',
+                              '--experimental-features',
+                              'nix-command',
+                              'to-base32',
+                              '--type',
+                              'sha256',
+                              digest16],
+                             stdout=subprocess.PIPE)

     v.result(process.returncode == 0)
     return Digest32(process.stdout.decode().strip())
 
     v.result(process.returncode == 0)
     return Digest32(process.stdout.decode().strip())
 


@@ -304,13 +362,6 @@ def fetch_resources(
     v.result(open(table['git-revision'].file).read(999) == pin.git_revision)
 
 
     v.result(open(table['git-revision'].file).read(999) == pin.git_revision)
 
 

-def git_cachedir(git_repo: str) -> str:
-    return os.path.join(
-        xdg.XDG_CACHE_HOME,
-        'pinch/git',
-        digest_string(git_repo.encode()))
-
-

 def tarball_cache_file(channel: TarrableSearchPath, pin: GitPin) -> str:
     return os.path.join(
         xdg.XDG_CACHE_HOME,
 def tarball_cache_file(channel: TarrableSearchPath, pin: GitPin) -> str:
     return os.path.join(
         xdg.XDG_CACHE_HOME,


@@ -324,101 +375,19 @@ def tarball_cache_file(channel: TarrableSearchPath, pin: GitPin) -> str:
 def verify_git_ancestry(
         v: Verification,
         channel: TarrableSearchPath,
 def verify_git_ancestry(
         v: Verification,
         channel: TarrableSearchPath,

-        new_revision: str,
-        old_revision: Optional[str]) -> None:
-    cachedir = git_cachedir(channel.git_repo)
-    v.status('Verifying rev is an ancestor of ref')
+        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',
                               cachedir,
                               'merge-base',
                               '--is-ancestor',
     process = subprocess.run(['git',
                               '-C',
                               cachedir,
                               'merge-base',
                               '--is-ancestor',

-                              new_revision,
-                              channel.git_ref])
+                              old_revision,
+                              new_revision])

     v.result(process.returncode == 0)
 
     v.result(process.returncode == 0)
 

-    if old_revision is not None:
-        v.status(
-            'Verifying rev is an ancestor of previous rev %s' %
-            old_revision)
-        process = subprocess.run(['git',
-                                  '-C',
-                                  cachedir,
-                                  'merge-base',
-                                  '--is-ancestor',
-                                  old_revision,
-                                  new_revision])
-        v.result(process.returncode == 0)
-
-
-def git_fetch(
-        v: Verification,
-        channel: TarrableSearchPath,
-        desired_revision: Optional[str],
-        old_revision: Optional[str]) -> str:
-    # 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.
-    # :(
-
-    cachedir = git_cachedir(channel.git_repo)
-    if not os.path.exists(cachedir):
-        v.status("Initializing git repo")
-        process = subprocess.run(
-            ['git', 'init', '--bare', cachedir])
-        v.result(process.returncode == 0)
-
-    v.status('Fetching ref "%s" from %s' % (channel.git_ref, channel.git_repo))
-    # We don't use --force here because we want to abort and freak out if forced
-    # updates are happening.
-    process = subprocess.run(['git',
-                              '-C',
-                              cachedir,
-                              'fetch',
-                              channel.git_repo,
-                              '%s:%s' % (channel.git_ref,
-                                         channel.git_ref)])
-    v.result(process.returncode == 0)
-
-    if desired_revision is not None:
-        v.status('Verifying that fetch retrieved this rev')
-        process = subprocess.run(
-            ['git', '-C', cachedir, 'cat-file', '-e', desired_revision])
-        v.result(process.returncode == 0)
-
-    new_revision = open(
-        os.path.join(
-            cachedir,
-            'refs',
-            'heads',
-            channel.git_ref)).read(999).strip()
-
-    verify_git_ancestry(v, channel, new_revision, old_revision)
-
-    return new_revision
-
-
-def ensure_git_rev_available(
-        v: Verification,
-        channel: TarrableSearchPath,
-        pin: GitPin,
-        old_revision: Optional[str]) -> None:
-    cachedir = git_cachedir(channel.git_repo)
-    if os.path.exists(cachedir):
-        v.status('Checking if we already have this rev:')
-        process = subprocess.run(
-            ['git', '-C', cachedir, 'cat-file', '-e', pin.git_revision])
-        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 == 0:
-            verify_git_ancestry(v, channel, pin.git_revision, old_revision)
-            return
-    git_fetch(v, channel, pin.git_revision, old_revision)
-

 
 def compare_tarball_and_git(
         v: Verification,
 
 def compare_tarball_and_git(
         v: Verification,


@@ -470,7 +439,7 @@ def git_checkout(
     v.status('Checking out corresponding git revision')
     git = subprocess.Popen(['git',
                             '-C',
     v.status('Checking out corresponding git revision')
     git = subprocess.Popen(['git',
                             '-C',

-                            git_cachedir(channel.git_repo),
+                            git_cache.git_cachedir(channel.git_repo),

                             'archive',
                             pin.git_revision],
                            stdout=subprocess.PIPE)
                             'archive',
                             pin.git_revision],
                            stdout=subprocess.PIPE)


@@ -502,7 +471,7 @@ def git_get_tarball(
                 pin.git_revision)
             git = subprocess.Popen(['git',
                                     '-C',
                 pin.git_revision)
             git = subprocess.Popen(['git',
                                     '-C',

-                                    git_cachedir(channel.git_repo),
+                                    git_cache.git_cachedir(channel.git_repo),

                                     'archive',
                                     '--prefix=%s/' % pin.release_name,
                                     pin.git_revision],
                                     'archive',
                                     '--prefix=%s/' % pin.release_name,
                                     pin.git_revision],


@@ -512,11 +481,7 @@ def git_get_tarball(
             git.wait()
             v.result(git.returncode == 0 and xz.returncode == 0)
 
             git.wait()
             v.result(git.returncode == 0 and xz.returncode == 0)
 

-        v.status('Putting tarball in Nix store')
-        process = subprocess.run(
-            ['nix-store', '--add', output_filename], stdout=subprocess.PIPE)
-        v.result(process.returncode == 0)
-        store_tarball = process.stdout.decode().strip()
+        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)
 
         os.makedirs(os.path.dirname(cache_file), exist_ok=True)
         open(cache_file, 'w').write(store_tarball)


@@ -573,7 +538,7 @@ def git_revision_name(
     v.status('Getting commit date')
     process = subprocess.run(['git',
                               '-C',
     v.status('Getting commit date')
     process = subprocess.run(['git',
                               '-C',

-                              git_cachedir(channel.git_repo),
+                              git_cache.git_cachedir(channel.git_repo),

                               'log',
                               '-n1',
                               '--format=%ct-%h',
                               'log',
                               '-n1',
                               '--format=%ct-%h',


@@ -590,34 +555,50 @@ K = TypeVar('K')
 V = TypeVar('V')
 
 
 V = TypeVar('V')
 
 

-def filter_dict(d: Dict[K, V], fields: Set[K]
-                ) -> Tuple[Dict[K, V], Dict[K, 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():
     selected: Dict[K, V] = {}
     remaining: Dict[K, V] = {}
     for k, v in d.items():

-        if k in fields:
+        if pred(k, v):

             selected[k] = v
         else:
             remaining[k] = v
     return selected, remaining
 
 
             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),
 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 == ()
     }
     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[call-arg]
+    pin = P(**pin_fields) if pin_present else None  # type: ignore

     return SP(**remaining_fields), pin
 
 
     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)
 def read_config(filename: str) -> configparser.ConfigParser:
     config = configparser.ConfigParser()
     config.read_file(open(filename), filename)


@@ -654,29 +635,29 @@ def pinCommand(args: argparse.Namespace) -> None:
 def updateCommand(args: argparse.Namespace) -> None:
     v = Verification()
     exprs: Dict[str, str] = {}
 def updateCommand(args: argparse.Namespace) -> None:
     v = Verification()
     exprs: Dict[str, str] = {}

-    config = read_config_files(args.channels_file)
-    for section in config:
-        sp, pin = read_config_section(config[section])
-        if pin is None:
-            raise Exception(
-                'Cannot update unpinned channel "%s" (Run "pin" before "update")' %
-                section)
-        if isinstance(sp, AliasSearchPath):
-            continue
+    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 nonalias.items():
+        assert not isinstance(sp, AliasSearchPath)  # mypy can't see through
+        assert not isinstance(pin, AliasPin)        # partition_dict()

         tarball = sp.fetch(v, pin)
         exprs[section] = (
             'f: f { name = "%s"; channelName = "%%s"; src = builtins.storePath "%s"; }' %
         tarball = sp.fetch(v, pin)
         exprs[section] = (
             'f: f { name = "%s"; channelName = "%%s"; src = builtins.storePath "%s"; }' %

-            (config[section]['release_name'], tarball))
+            (pin.release_name, tarball))

 
 

-    for section in config:
-        if 'alias_of' in config[section]:
-            exprs[section] = exprs[str(config[section]['alias_of'])]
+    for section, (sp, pin) in alias.items():
+        assert isinstance(sp, AliasSearchPath)  # For mypy
+        exprs[section] = exprs[sp.alias_of]

 
     command = [
         'nix-env',
         '--profile',
 
     command = [
         'nix-env',
         '--profile',

-        '/nix/var/nix/profiles/per-user/%s/channels' %
-        getpass.getuser(),
+        args.profile,

         '--show-trace',
         '--file',
         '<nix/unpack-channel.nix>',
         '--show-trace',
         '--file',
         '<nix/unpack-channel.nix>',


@@ -699,6 +680,8 @@ def main() -> None:
     parser_pin.set_defaults(func=pinCommand)
     parser_update = subparsers.add_parser('update')
     parser_update.add_argument('--dry-run', action='store_true')
     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()
     parser_update.add_argument('channels_file', type=str, nargs='+')
     parser_update.set_defaults(func=updateCommand)
     args = parser.parse_args()