X-Git-Url: http://git.scottworley.com/pinch/blobdiff_plain/dc038df02de3df877d535f1c978ad7537eaf70a8..597bd03a184f89d9f46271dfb18da72812f8a8b7:/pinch.py?ds=inline

diff --git a/pinch.py b/pinch.py
index e00bfd8..5bb4e95 100644
--- a/pinch.py
+++ b/pinch.py
@@ -1,5 +1,8 @@
+import argparse
+import configparser
 import filecmp
 import functools
+import getpass
 import hashlib
 import operator
 import os
@@ -25,6 +28,7 @@ Digest32 = NewType('Digest32', str)
 
 
 class ChannelTableEntry(types.SimpleNamespace):
+    absolute_url: str
     digest: Digest16
     file: str
     size: int
@@ -33,14 +37,14 @@ class ChannelTableEntry(types.SimpleNamespace):
 
 class Channel(types.SimpleNamespace):
     channel_html: bytes
+    channel_url: str
     forwarded_url: str
-    git_cachedir: str
     git_ref: str
     git_repo: str
     git_revision: str
+    old_git_revision: str
     release_name: str
     table: Dict[str, ChannelTableEntry]
-    url: str
 
 
 class VerificationError(Exception):
@@ -108,11 +112,11 @@ def compare(a: str, b: str) -> Tuple[List[str], List[str], List[str]]:
 
 def fetch(v: Verification, channel: Channel) -> None:
     v.status('Fetching channel')
-    request = urllib.request.urlopen(channel.url, timeout=10)
+    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.check('Got forwarded', channel.url != channel.forwarded_url)
+    v.check('Got forwarded', channel.channel_url != channel.forwarded_url)
 
 
 def parse_channel(v: Verification, channel: Channel) -> None:
@@ -130,8 +134,8 @@ def parse_channel(v: Verification, channel: Channel) -> None:
 
     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)
+    channel.git_revision = git_commit_node.firstChild.nodeValue
+    v.status(channel.git_revision)
     v.ok()
     v.status('Verifying git commit label')
     v.result(git_commit_node.previousSibling.nodeValue == 'Git commit ')
@@ -198,12 +202,48 @@ def fetch_with_nix_prefetch_url(
 def fetch_resources(v: Verification, channel: Channel) -> 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.absolute_url = urllib.parse.urljoin(
+            channel.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)
+            channel.table['git-revision'].file).read(999) == channel.git_revision)
+
+
+def git_cachedir(git_repo: str) -> str:
+    # TODO: Consider using pyxdg to find this path.
+    return os.path.expanduser(
+        '~/.cache/nix-pin-channel/git/%s' %
+        digest_string(
+            git_repo.encode()))
+
+
+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:
@@ -213,116 +253,275 @@ 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.url.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)
 
-    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('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('Verifying that fetch retrieved this rev')
         process = subprocess.run(
-            ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.git_commit])
+            ['git', '-C', cachedir, 'cat-file', '-e', channel.git_revision])
         v.result(process.returncode == 0)
+    else:
+        channel.git_revision = open(
+            os.path.join(
+                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_commit,
-                              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(
+        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',
+                            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()
+    tar.wait()
+    git.wait()
+    v.result(git.returncode == 0 and tar.returncode == 0)
+
+
+def git_get_tarball(v: Verification, channel: Channel) -> str:
+    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], capture_output=True)
+        v.result(process.returncode == 0)
+        return process.stdout.decode().strip()
+
+
+def check_channel_metadata(
+        v: Verification,
+        channel: Channel,
+        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_revision)
+
+    v.status(
+        'Verifying version-suffix is a suffix of release name %s:' %
+        channel.release_name)
+    version_suffix = open(
+        os.path.join(
+            channel_contents,
+            channel.release_name,
+            '.version-suffix')).read(999)
+    v.status(version_suffix)
+    v.result(channel.release_name.endswith(version_suffix))
 
 
 def check_channel_contents(v: Verification, channel: Channel) -> None:
     with tempfile.TemporaryDirectory() as channel_contents, \
             tempfile.TemporaryDirectory() as git_contents:
-        v.status('Extracting tarball %s' %
-                 channel.table['nixexprs.tar.xz'].file)
-        shutil.unpack_archive(
-            channel.table['nixexprs.tar.xz'].file,
-            channel_contents)
-        v.ok()
-        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', git_contents, '-f', '-'], stdin=git.stdout)
-        git.stdout.close()
-        tar.wait()
-        git.wait()
-        v.result(git.returncode == 0 and tar.returncode == 0)
-        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))
+
+        extract_tarball(v, channel, channel_contents)
+        check_channel_metadata(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()
-    channel = Channel(url='https://channels.nixos.org/nixos-20.03',
-                      git_repo='https://github.com/NixOS/nixpkgs.git',
-                      git_ref='nixos-20.03')
+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)
-    print(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),
+                              'lo',
+                              '-n1',
+                              '--format=%ct-%h',
+                              '--abbrev=11',
+                              channel.git_revision],
+                             capture_output=True)
+    v.result(process.returncode == 0 and process.stdout != '')
+    return '%s-%s' % (os.path.basename(channel.git_repo),
+                      process.stdout.decode().strip())
+
+
+def pin(args: argparse.Namespace) -> None:
+    v = Verification()
+    config = configparser.ConfigParser()
+    config.read_file(open(args.channels_file), args.channels_file)
+    for section in config.sections():
+
+        channel = Channel(**dict(config[section].items()))
+        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(args.channels_file, 'w') as configfile:
+        config.write(configfile)
+
+
+def update(args: argparse.Namespace) -> None:
+    v = Verification()
+    config = configparser.ConfigParser()
+    config.read_file(open(args.channels_file), args.channels_file)
+    exprs = []
+    for section in config.sections():
+        if 'channel_url' in config[section]:
+            tarball = fetch_with_nix_prefetch_url(
+                v, config[section]['tarball_url'], Digest16(
+                    config[section]['tarball_sha256']))
+        else:
+            channel = Channel(**dict(config[section].items()))
+            ensure_git_rev_available(v, channel)
+            tarball = git_get_tarball(v, channel)
+        exprs.append(
+            'f: f { name = "%s"; channelName = "%s"; src = builtins.storePath "%s"; }' %
+            (config[section]['release_name'], section, tarball))
+    v.status('Installing channels with nix-env')
+    process = subprocess.run(
+        [
+            'nix-env',
+            '--profile',
+            '/nix/var/nix/profiles/per-user/%s/channels' %
+            getpass.getuser(),
+            '--show-trace',
+            '--file',
+            '<nix/unpack-channel.nix>',
+            '--install',
+            '--from-expression'] +
+        exprs)
+    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.set_defaults(func=pin)
+    parser_update = subparsers.add_parser('update')
+    parser_update.add_argument('channels_file', type=str)
+    parser_update.set_defaults(func=update)
+    args = parser.parse_args()
+    args.func(args)
 
 
 main()