X-Git-Url: http://git.scottworley.com/pinch/blobdiff_plain/8fca6c28975315a042f0544b42cb4a15d8dfa192..2b0b80e7e213e3e165cea4b80f5aa99377d9442c:/pinch.py?ds=inline

diff --git a/pinch.py b/pinch.py
index 80e631b..47f4e34 100644
--- a/pinch.py
+++ b/pinch.py
@@ -1,10 +1,13 @@
+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
@@ -22,6 +25,19 @@ from typing import (
     Tuple,
 )
 
+# Use xdg module when it's less painful to have as a dependency
+
+
+class XDG(types.SimpleNamespace):
+    XDG_CACHE_HOME: str
+
+
+xdg = XDG(
+    XDG_CACHE_HOME=os.getenv(
+        'XDG_CACHE_HOME',
+        os.path.expanduser('~/.cache')))
+
+
 Digest16 = NewType('Digest16', str)
 Digest32 = NewType('Digest32', str)
 
@@ -35,10 +51,10 @@ class ChannelTableEntry(types.SimpleNamespace):
 
 
 class Channel(types.SimpleNamespace):
+    alias_of: str
     channel_html: bytes
     channel_url: str
     forwarded_url: str
-    git_cachedir: str
     git_ref: str
     git_repo: str
     git_revision: str
@@ -57,7 +73,7 @@ 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
@@ -67,9 +83,9 @@ 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()
@@ -115,7 +131,7 @@ def fetch(v: Verification, channel: Channel) -> None:
     request = urllib.request.urlopen(channel.channel_url, timeout=10)
     channel.channel_html = request.read()
     channel.forwarded_url = request.geturl()
-    v.result(request.status == 200)
+    v.result(request.status == 200)  # type: ignore  # (for old mypy)
     v.check('Got forwarded', channel.channel_url != channel.forwarded_url)
 
 
@@ -168,7 +184,7 @@ def digest_file(filename: str) -> Digest16:
 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)
+        ['nix', 'to-base16', '--type', 'sha256', digest32], stdout=subprocess.PIPE)
     v.result(process.returncode == 0)
     return Digest16(process.stdout.decode().strip())
 
@@ -176,7 +192,7 @@ def to_Digest16(v: Verification, digest32: Digest32) -> Digest16:
 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)
+        ['nix', 'to-base32', '--type', 'sha256', digest16], stdout=subprocess.PIPE)
     v.result(process.returncode == 0)
     return Digest32(process.stdout.decode().strip())
 
@@ -187,7 +203,7 @@ 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 == ''
@@ -196,7 +212,7 @@ def fetch_with_nix_prefetch_url(
     v.status("Verifying file digest")
     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:
@@ -212,6 +228,49 @@ def fetch_resources(v: Verification, channel: Channel) -> None:
             channel.table['git-revision'].file).read(999) == channel.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: Channel) -> str:
+    return os.path.join(
+        xdg.XDG_CACHE_HOME,
+        'pinch/git-tarball',
+        '%s-%s-%s' %
+        (digest_string(channel.git_repo.encode()),
+         channel.git_revision,
+         channel.release_name))
+
+
+def verify_git_ancestry(v: Verification, channel: Channel) -> None:
+    cachedir = git_cachedir(channel.git_repo)
+    v.status('Verifying rev is an ancestor of ref')
+    process = subprocess.run(['git',
+                              '-C',
+                              cachedir,
+                              'merge-base',
+                              '--is-ancestor',
+                              channel.git_revision,
+                              channel.git_ref])
+    v.result(process.returncode == 0)
+
+    if hasattr(channel, 'old_git_revision'):
+        v.status(
+            'Verifying rev is an ancestor of previous rev %s' %
+            channel.old_git_revision)
+        process = subprocess.run(['git',
+                                  '-C',
+                                  cachedir,
+                                  'merge-base',
+                                  '--is-ancestor',
+                                  channel.old_git_revision,
+                                  channel.git_revision])
+        v.result(process.returncode == 0)
+
+
 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
@@ -219,64 +278,56 @@ def git_fetch(v: Verification, channel: Channel) -> None:
     # 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.git_repo.encode()))
-    if not os.path.exists(channel.git_cachedir):
+    cachedir = git_cachedir(channel.git_repo)
+    if not os.path.exists(cachedir):
         v.status("Initializing git repo")
         process = subprocess.run(
-            ['git', 'init', '--bare', channel.git_cachedir])
+            ['git', 'init', '--bare', cachedir])
         v.result(process.returncode == 0)
 
-    have_rev = False
+    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 hasattr(channel, 'git_revision'):
-        v.status('Checking if we already have this rev:')
+        v.status('Verifying that fetch retrieved this rev')
         process = subprocess.run(
-            ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.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)
-        have_rev = process.returncode == 0
-
-    if not have_rev:
-        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',
-                                  channel.git_cachedir,
-                                  'fetch',
-                                  channel.git_repo,
-                                  '%s:%s' % (channel.git_ref,
-                                             channel.git_ref)])
+            ['git', '-C', cachedir, 'cat-file', '-e', channel.git_revision])
         v.result(process.returncode == 0)
-        if hasattr(channel, 'git_revision'):
-            v.status('Verifying that fetch retrieved this rev')
-            process = subprocess.run(
-                ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.git_revision])
-            v.result(process.returncode == 0)
-
-    if not hasattr(channel, 'git_revision'):
+    else:
         channel.git_revision = open(
             os.path.join(
-                channel.git_cachedir,
+                cachedir,
                 'refs',
                 'heads',
                 channel.git_ref)).read(999).strip()
 
-    v.status('Verifying rev is an ancestor of ref')
-    process = subprocess.run(['git',
-                              '-C',
-                              channel.git_cachedir,
-                              'merge-base',
-                              '--is-ancestor',
-                              channel.git_revision,
-                              channel.git_ref])
-    v.result(process.returncode == 0)
+    verify_git_ancestry(v, channel)
+
+
+def ensure_git_rev_available(v: Verification, channel: Channel) -> 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', channel.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)
+            return
+    git_fetch(v, channel)
 
 
 def compare_tarball_and_git(
@@ -325,18 +376,56 @@ 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,
+                            git_cachedir(channel.git_repo),
                             'archive',
                             channel.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: Channel) -> str:
+    cache_file = tarball_cache_file(channel)
+    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, channel.release_name + '.tar.xz')
+        with open(output_filename, 'w') as output_file:
+            v.status(
+                'Generating tarball for git revision %s' %
+                channel.git_revision)
+            git = subprocess.Popen(['git',
+                                    '-C',
+                                    git_cachedir(channel.git_repo),
+                                    'archive',
+                                    '--prefix=%s/' % channel.release_name,
+                                    channel.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)
+
+        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()
+
+        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,
@@ -380,34 +469,139 @@ def pin_channel(v: Verification, channel: Channel) -> None:
     fetch(v, channel)
     parse_channel(v, channel)
     fetch_resources(v, channel)
-    git_fetch(v, channel)
+    ensure_git_rev_available(v, channel)
     check_channel_contents(v, channel)
 
 
-def make_channel(conf: configparser.SectionProxy) -> Channel:
-    channel = Channel(**dict(conf.items()))
-    if hasattr(channel, 'git_revision'):
-        channel.old_git_revision = channel.git_revision
-        del channel.git_revision
-    return channel
+def git_revision_name(v: Verification, channel: Channel) -> str:
+    v.status('Getting commit date')
+    process = subprocess.run(['git',
+                              '-C',
+                              git_cachedir(channel.git_repo),
+                              'log',
+                              '-n1',
+                              '--format=%ct-%h',
+                              '--abbrev=11',
+                              '--no-show-signature',
+                              channel.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())
+
+
+def read_config(filename: str) -> configparser.ConfigParser:
+    config = configparser.ConfigParser()
+    config.read_file(open(filename), filename)
+    return config
 
 
-def main(argv: List[str]) -> None:
+def pin(args: argparse.Namespace) -> None:
     v = Verification()
-    config = configparser.ConfigParser()
-    config.read_file(open(argv[1]), argv[1])
+    config = read_config(args.channels_file)
     for section in config.sections():
-        channel = make_channel(config[section])
+        if args.channels and section not in args.channels:
+            continue
+
+        channel = Channel(**dict(config[section].items()))
+
+        if hasattr(channel, 'alias_of'):
+            assert not hasattr(channel, 'git_repo')
+            continue
+
+        if hasattr(channel, 'git_revision'):
+            channel.old_git_revision = channel.git_revision
+            del channel.git_revision
+
         if 'channel_url' in config[section]:
             pin_channel(v, channel)
+            config[section]['release_name'] = channel.release_name
             config[section]['tarball_url'] = channel.table['nixexprs.tar.xz'].absolute_url
             config[section]['tarball_sha256'] = channel.table['nixexprs.tar.xz'].digest
         else:
             git_fetch(v, channel)
+            config[section]['release_name'] = git_revision_name(v, channel)
         config[section]['git_revision'] = channel.git_revision
 
-    with open(argv[1], 'w') as configfile:
+    with open(args.channels_file, 'w') as configfile:
         config.write(configfile)
 
 
-main(sys.argv)
+def fetch_channel(
+        v: Verification,
+        section: str,
+        conf: configparser.SectionProxy) -> str:
+    if 'git_repo' not in conf or 'release_name' not in conf:
+        raise Exception(
+            'Cannot update unpinned channel "%s" (Run "pin" before "update")' %
+            section)
+
+    if 'channel_url' in conf:
+        return fetch_with_nix_prefetch_url(
+            v, conf['tarball_url'], Digest16(
+                conf['tarball_sha256']))
+
+    channel = Channel(**dict(conf.items()))
+    ensure_git_rev_available(v, channel)
+    return git_get_tarball(v, channel)
+
+
+def update(args: argparse.Namespace) -> None:
+    v = Verification()
+    config = configparser.ConfigParser()
+    exprs: Dict[str, str] = {}
+    configs = [read_config(filename) for filename in args.channels_file]
+    for config in configs:
+        for section in config.sections():
+            if 'alias_of' in config[section]:
+                assert 'git_repo' not in config[section]
+                continue
+            tarball = fetch_channel(v, section, config[section])
+            if section in exprs:
+                raise Exception('Duplicate channel "%s"' % section)
+            exprs[section] = (
+                'f: f { name = "%s"; channelName = "%%s"; src = builtins.storePath "%s"; }' %
+                (config[section]['release_name'], tarball))
+
+    for config in configs:
+        for section in config.sections():
+            if 'alias_of' in config[section]:
+                if section in exprs:
+                    raise Exception('Duplicate channel "%s"' % section)
+                exprs[section] = exprs[str(config[section]['alias_of'])]
+
+    command = [
+        'nix-env',
+        '--profile',
+        '/nix/var/nix/profiles/per-user/%s/channels' %
+        getpass.getuser(),
+        '--show-trace',
+        '--file',
+        '<nix/unpack-channel.nix>',
+        '--install',
+        '--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=pin)
+    parser_update = subparsers.add_parser('update')
+    parser_update.add_argument('--dry-run', action='store_true')
+    parser_update.add_argument('channels_file', type=str, nargs='+')
+    parser_update.set_defaults(func=update)
+    args = parser.parse_args()
+    args.func(args)
+
+
+if __name__ == '__main__':
+    main()