]> git.scottworley.com Git - pinch/blobdiff - pinch.py
Rename top-level procedures
[pinch] / pinch.py
index cdc0ba8c64fbac003e623badbd49f471cf675816..f0f0422047a0f434b9c07c618a9ac5dea45f84ea 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -5,6 +5,7 @@ import operator
 import os
 import os.path
 import shutil
+import subprocess
 import tempfile
 import types
 import urllib.parse
@@ -15,14 +16,17 @@ from typing import (
     Dict,
     Iterable,
     List,
+    NewType,
     Sequence,
     Tuple,
 )
 
+Digest16 = NewType('Digest16', str)
+Digest32 = NewType('Digest32', str)
+
 
 class InfoTableEntry(types.SimpleNamespace):
-    content: bytes
-    digest: str
+    digest: Digest16
     file: str
     size: int
     url: str
@@ -32,6 +36,7 @@ class Info(types.SimpleNamespace):
     channel_html: bytes
     forwarded_url: str
     git_revision: str
+    release_name: str
     table: Dict[str, InfoTableEntry]
     url: str
 
@@ -115,14 +120,23 @@ def fetch(v: Verification, channel_url: str) -> Info:
     return info
 
 
-def parse(v: Verification, info: Info) -> None:
+def parse_channel(v: Verification, info: Info) -> None:
     v.status('Parsing channel description as XML')
     d = xml.dom.minidom.parseString(info.channel_html)
     v.ok()
 
-    v.status('Extracting git commit')
+    v.status('Extracting release name:')
+    title_name = d.getElementsByTagName(
+        'title')[0].firstChild.nodeValue.split()[2]
+    h1_name = d.getElementsByTagName('h1')[0].firstChild.nodeValue.split()[2]
+    v.status(title_name)
+    v.result(title_name == h1_name)
+    info.release_name = title_name
+
+    v.status('Extracting git commit:')
     git_commit_node = d.getElementsByTagName('tt')[0]
     info.git_commit = git_commit_node.firstChild.nodeValue
+    v.status(info.git_commit)
     v.ok()
     v.status('Verifying git commit label')
     v.result(git_commit_node.previousSibling.nodeValue == 'Git commit ')
@@ -133,43 +147,68 @@ def parse(v: Verification, info: Info) -> None:
         name = row.childNodes[0].firstChild.firstChild.nodeValue
         url = row.childNodes[0].firstChild.getAttribute('href')
         size = int(row.childNodes[1].firstChild.nodeValue)
-        digest = row.childNodes[2].firstChild.firstChild.nodeValue
+        digest = Digest16(row.childNodes[2].firstChild.firstChild.nodeValue)
         info.table[name] = InfoTableEntry(url=url, digest=digest, size=size)
     v.ok()
 
 
-def fetch_resources(v: Verification, info: Info) -> None:
+def digest_file(filename: str) -> Digest16:
+    hasher = hashlib.sha256()
+    with open(filename, 'rb') as f:
+        # pylint: disable=cell-var-from-loop
+        for block in iter(lambda: f.read(4096), b''):
+            hasher.update(block)
+    return Digest16(hasher.hexdigest())
+
+
+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)
+    v.result(process.returncode == 0)
+    return Digest16(process.stdout.decode().strip())
+
+
+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)
+    v.result(process.returncode == 0)
+    return Digest32(process.stdout.decode().strip())
+
+
+def fetch_with_nix_prefetch_url(
+        v: Verification,
+        url: str,
+        digest: Digest16) -> str:
+    v.status('Fetching %s' % url)
+    process = subprocess.run(
+        ['nix-prefetch-url', '--print-path', url, digest], capture_output=True)
+    v.result(process.returncode == 0)
+    prefetch_digest, path, empty = process.stdout.decode().split('\n')
+    assert empty == ''
+    v.check("Verifying nix-prefetch-url's digest",
+            to_Digest16(v, Digest32(prefetch_digest)) == digest)
+    v.status("Verifying file digest")
+    file_digest = digest_file(path)
+    v.result(file_digest == digest)
+    return path
+
 
+def fetch_resources(v: Verification, info: Info) -> None:
     for resource in ['git-revision', 'nixexprs.tar.xz']:
         fields = info.table[resource]
-        v.status('Fetching resource "%s"' % resource)
         url = urllib.parse.urljoin(info.forwarded_url, fields.url)
-        request = urllib.request.urlopen(url, timeout=10)
-        if fields.size < 4096:
-            fields.content = request.read()
-        else:
-            with tempfile.NamedTemporaryFile(suffix='.nixexprs.tar.xz', delete=False) as tmp_file:
-                shutil.copyfileobj(request, tmp_file)
-                fields.file = tmp_file.name
-        v.result(request.status == 200)
-        v.status('Verifying digest for "%s"' % resource)
-        if fields.size < 4096:
-            actual_hash = hashlib.sha256(fields.content).hexdigest()
-        else:
-            hasher = hashlib.sha256()
-            with open(fields.file, 'rb') as f:
-                # pylint: disable=cell-var-from-loop
-                for block in iter(lambda: f.read(4096), b''):
-                    hasher.update(block)
-            actual_hash = hasher.hexdigest()
-        v.result(actual_hash == fields.digest)
-    v.check('Verifying git commit on main page matches git commit in table',
-            info.table['git-revision'].content.decode() == info.git_commit)
-
-
-def extract_channel(v: Verification, info: Info) -> None:
+        fields.file = fetch_with_nix_prefetch_url(v, url, fields.digest)
+    v.status('Verifying git commit on main page matches git commit in table')
+    v.result(
+        open(
+            info.table['git-revision'].file).read(999) == info.git_commit)
+
+
+def check_channel_contents(v: Verification, info: Info) -> None:
     with tempfile.TemporaryDirectory() as d:
-        v.status('Extracting nixexprs.tar.xz')
+        v.status('Extracting %s' % info.table['nixexprs.tar.xz'].file)
         shutil.unpack_archive(info.table['nixexprs.tar.xz'].file, d)
         v.ok()
         v.status('Removing temporary directory')
@@ -179,9 +218,9 @@ def extract_channel(v: Verification, info: Info) -> None:
 def main() -> None:
     v = Verification()
     info = fetch(v, 'https://channels.nixos.org/nixos-20.03')
-    parse(v, info)
+    parse_channel(v, info)
     fetch_resources(v, info)
-    extract_channel(v, info)
+    check_channel_contents(v, info)
     print(info)