]> git.scottworley.com Git - pinch/blobdiff - pinch.py
Better error message for running "update" before "pin"
[pinch] / pinch.py
index 1a97f5377fe4c063fb448f6aba16dc7ac5b3aca4..f84440c5c0fd54e4831b893edc4c7ed94a446909 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -1,11 +1,16 @@
+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 tempfile
 import types
 import urllib.parse
@@ -20,11 +25,15 @@ from typing import (
     Tuple,
 )
 
+import xdg
+
+
 Digest16 = NewType('Digest16', str)
 Digest32 = NewType('Digest32', str)
 
 
 class ChannelTableEntry(types.SimpleNamespace):
+    absolute_url: str
     digest: Digest16
     file: str
     size: int
@@ -32,15 +41,16 @@ 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
+    old_git_revision: str
     release_name: str
     table: Dict[str, ChannelTableEntry]
-    url: str
 
 
 class VerificationError(Exception):
@@ -53,7 +63,7 @@ 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
@@ -65,7 +75,7 @@ class Verification:
         length = len(message)
         cols = shutil.get_terminal_size().columns
         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()
@@ -108,11 +118,11 @@ 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 +140,8 @@ 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 +208,48 @@ 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:
+    return os.path.join(
+        xdg.XDG_CACHE_HOME,
+        'pinch/git',
+        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:
@@ -213,51 +259,56 @@ 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.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(
@@ -306,23 +357,77 @@ 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_commit],
+                            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:
+    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:
 
         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)
@@ -331,17 +436,137 @@ def check_channel_contents(v: Verification, channel: Channel) -> None:
     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 != 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 pin(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
+
+        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(args.channels_file, 'w') as configfile:
+        config.write(configfile)
+
+
+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
+
+            if 'git_repo' not in config[section] or 'release_name' not in config[section]:
+                raise Exception(
+                    'Cannot update unpinned channel "%s" (Run "pin" before "update")' %
+                    section)
+
+            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)
+
+            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)
 
 
 main()