Split ensure_git_rev_available out from git_fetch

[pinch] / pinch.py

diff --git a/pinch.py b/pinch.py
index dd707180d0ff474a2af30d649a98a44c80be32ca..0f8f00a611390cff8aaca8e20ff0d1361a4a4274 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -1,3 +1,4 @@
+import argparse

 import configparser
 import filecmp
 import functools
 import configparser
 import filecmp
 import functools


@@ -7,7 +8,6 @@ import os
 import os.path
 import shutil
 import subprocess
 import os.path
 import shutil
 import subprocess

-import sys

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


@@ -36,14 +36,14 @@ class ChannelTableEntry(types.SimpleNamespace):
 
 class Channel(types.SimpleNamespace):
     channel_html: bytes
 
 class Channel(types.SimpleNamespace):
     channel_html: bytes

+    channel_url: str

     forwarded_url: str
     forwarded_url: str

-    git_cachedir: str

     git_ref: str
     git_repo: str
     git_revision: str
     git_ref: str
     git_repo: str
     git_revision: str

+    old_git_revision: str

     release_name: str
     table: Dict[str, ChannelTableEntry]
     release_name: str
     table: Dict[str, ChannelTableEntry]

-    url: str

 
 
 class VerificationError(Exception):
 
 
 class VerificationError(Exception):


@@ -111,11 +111,11 @@ def compare(a: str, b: str) -> Tuple[List[str], List[str], List[str]]:
 
 def fetch(v: Verification, channel: Channel) -> None:
     v.status('Fetching channel')
 
 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)
     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:
 
 
 def parse_channel(v: Verification, channel: Channel) -> None:


@@ -211,6 +211,40 @@ def fetch_resources(v: Verification, channel: Channel) -> None:
             channel.table['git-revision'].file).read(999) == channel.git_revision)
 
 
             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:
     # 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
 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


@@ -218,51 +252,56 @@ def git_fetch(v: Verification, channel: Channel) -> None:
     # details for my comfort.  So we re-implement here half of nix.fetchGit.
     # :(
 
     # 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(
         v.status("Initializing git repo")
         process = subprocess.run(

-            ['git', 'init', '--bare', channel.git_cachedir])
+            ['git', 'init', '--bare', cachedir])

         v.result(process.returncode == 0)
 
         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_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 == 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(
         v.status('Verifying that fetch retrieved this rev')
         process = subprocess.run(

-            ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.git_revision])
+            ['git', '-C', cachedir, 'cat-file', '-e', channel.git_revision])

         v.result(process.returncode == 0)
         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_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(
 
 
 def compare_tarball_and_git(


@@ -311,7 +350,7 @@ def git_checkout(v: Verification, channel: Channel, dest: str) -> None:
     v.status('Checking out corresponding git revision')
     git = subprocess.Popen(['git',
                             '-C',
     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)
                             'archive',
                             channel.git_revision],
                            stdout=subprocess.PIPE)


@@ -362,22 +401,66 @@ def check_channel_contents(v: Verification, channel: Channel) -> None:
     v.ok()
 
 
     v.ok()
 
 

-def main(argv: List[str]) -> None:
+def pin_channel(v: Verification, channel: Channel) -> None:
+    fetch(v, channel)
+    parse_channel(v, channel)
+    fetch_resources(v, channel)
+    ensure_git_rev_available(v, channel)
+    check_channel_contents(v, 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 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 pin(args: argparse.Namespace) -> None:

     v = Verification()
     config = configparser.ConfigParser()
     v = Verification()
     config = configparser.ConfigParser()

-    config.read_file(open(argv[1]), argv[1])
+    config.read_file(open(args.channels_file), args.channels_file)

     for section in config.sections():
     for section in config.sections():

-        channel = Channel(**dict(config[section].items()))
-        fetch(v, channel)
-        parse_channel(v, channel)
-        fetch_resources(v, channel)
-        git_fetch(v, channel)
-        check_channel_contents(v, channel)
-        config[section]['git_rev'] = channel.git_revision
-        config[section]['tarball_url'] = channel.table['nixexprs.tar.xz'].absolute_url
-        config[section]['tarball_sha256'] = channel.table['nixexprs.tar.xz'].digest
-    with open(argv[1], 'w') as configfile:
+        channel = make_channel(config[section])
+        if 'channel_url' in config[section]:
+            pin_channel(v, channel)
+            config[section]['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]['name'] = git_revision_name(v, channel)
+        config[section]['git_revision'] = channel.git_revision
+
+    with open(args.channels_file, 'w') as configfile:

         config.write(configfile)
 
 
         config.write(configfile)
 
 

-main(sys.argv)
+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)
+    args = parser.parse_args()
+    args.func(args)
+
+
+main()