From 8fca6c28975315a042f0544b42cb4a15d8dfa192 Mon Sep 17 00:00:00 2001
From: Scott Worley <scottworley@scottworley.com>
Date: Thu, 9 Apr 2020 21:44:49 -0700
Subject: [PATCH] Support non-hydra, plain ol' git channels

---
 pinch.py | 76 +++++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 53 insertions(+), 23 deletions(-)

diff --git a/pinch.py b/pinch.py
index e3b6882..80e631b 100644
--- a/pinch.py
+++ b/pinch.py
@@ -42,6 +42,7 @@ class Channel(types.SimpleNamespace):
     git_ref: str
     git_repo: str
     git_revision: str
+    old_git_revision: str
     release_name: str
     table: Dict[str, ChannelTableEntry]
 
@@ -229,16 +230,20 @@ def git_fetch(v: Verification, channel: Channel) -> None:
             ['git', 'init', '--bare', channel.git_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_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)
+    have_rev = False
+    if hasattr(channel, 'git_revision'):
+        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)
+        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',
@@ -249,10 +254,19 @@ def git_fetch(v: Verification, channel: Channel) -> None:
                                   '%s:%s' % (channel.git_ref,
                                              channel.git_ref)])
         v.result(process.returncode == 0)
-        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 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'):
+        channel.git_revision = open(
+            os.path.join(
+                channel.git_cachedir,
+                'refs',
+                'heads',
+                channel.git_ref)).read(999).strip()
 
     v.status('Verifying rev is an ancestor of ref')
     process = subprocess.run(['git',
@@ -362,20 +376,36 @@ def check_channel_contents(v: Verification, channel: Channel) -> None:
     v.ok()
 
 
+def pin_channel(v: Verification, channel: Channel) -> None:
+    fetch(v, channel)
+    parse_channel(v, channel)
+    fetch_resources(v, channel)
+    git_fetch(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 main(argv: List[str]) -> None:
     v = Verification()
     config = configparser.ConfigParser()
     config.read_file(open(argv[1]), argv[1])
     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
+        channel = make_channel(config[section])
+        if 'channel_url' in config[section]:
+            pin_channel(v, channel)
+            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]['git_revision'] = channel.git_revision
+
     with open(argv[1], 'w') as configfile:
         config.write(configfile)
 
-- 
2.44.1