pyrox.dev
1#! /usr/bin/env nix-shell
2#! nix-shell -p nix-prefetch-git "python3.withPackages (ps: with ps; [ lxml ])"
3#! nix-shell -i python
4
5import base64
6import json
7import re
8import subprocess
9from codecs import iterdecode
10from os.path import dirname, splitext
11from lxml import etree
12from lxml.etree import HTMLParser
13from urllib.request import urlopen
14
15# ChromiumOS components required to build crosvm.
16components = ['chromiumos/platform/crosvm', 'chromiumos/third_party/adhd']
17
18git_root = 'https://chromium.googlesource.com/'
19manifest_versions = f'{git_root}chromiumos/manifest-versions'
20buildspecs_url = f'{manifest_versions}/+/refs/heads/master/full/buildspecs/'
21
22# CrOS version numbers look like this:
23# [<chrome-major-version>.]<tip-build>.<branch-build>.<branch-branch-build>
24#
25# As far as I can tell, branches are where internal Google
26# modifications are added to turn Chromium OS into Chrome OS, and
27# branch branches are used for fixes for specific devices. So for
28# Chromium OS they will always be 0. This is a best guess, and is not
29# documented.
30with urlopen('https://cros-updates-serving.appspot.com/') as resp:
31 document = etree.parse(resp, HTMLParser())
32 # bgcolor="lightgreen" is set on the most up-to-date version for
33 # each channel, so find a lightgreen cell in the "Stable" column.
34 (platform_version, chrome_version) = document.xpath("""
35 (//table[@id="cros-updates"]/tr/td[1 + count(
36 //table[@id="cros-updates"]/thead/tr[1]/th[text() = "Stable"]
37 /preceding-sibling::*)
38 ][@bgcolor="lightgreen"])[1]/text()
39 """)
40
41chrome_major_version = re.match(r'\d+', chrome_version)[0]
42chromeos_tip_build = re.match(r'\d+', platform_version)[0]
43
44# Find the most recent buildspec for the stable Chrome version and
45# Chromium OS build number. Its branch build and branch branch build
46# numbers will (almost?) certainly be 0. It will then end with an rc
47# number -- presumably these are release candidates, one of which
48# becomes the final release. Presumably the one with the highest rc
49# number.
50with urlopen(f'{buildspecs_url}{chrome_major_version}/?format=TEXT') as resp:
51 listing = base64.decodebytes(resp.read()).decode('utf-8')
52 buildspecs = [(line.split('\t', 1)[1]) for line in listing.splitlines()]
53 buildspecs = [s for s in buildspecs if s.startswith(chromeos_tip_build)]
54 buildspecs.sort(reverse=True)
55 buildspec = splitext(buildspecs[0])[0]
56
57revisions = {}
58
59# Read the buildspec, and extract the git revisions for each component.
60with urlopen(f'{buildspecs_url}{chrome_major_version}/{buildspec}.xml?format=TEXT') as resp:
61 xml = base64.decodebytes(resp.read())
62 root = etree.fromstring(xml)
63 for project in root.findall('project'):
64 revisions[project.get('name')] = project.get('revision')
65
66# Initialize the data that will be output from this script. Leave the
67# rc number in buildspec so nobody else is subject to the same level
68# of confusion I have been.
69data = {'version': f'{chrome_major_version}.{buildspec}', 'components': {}}
70
71# Fill in the 'components' dictionary with the output from
72# nix-prefetch-git, which can be passed straight to fetchGit when
73# imported by Nix.
74for component in components:
75 argv = ['nix-prefetch-git',
76 '--url', git_root + component,
77 '--rev', revisions[component]]
78
79 output = subprocess.check_output(argv)
80 data['components'][component] = json.loads(output.decode('utf-8'))
81
82# Find the path to crosvm's default.nix, so the srcs data can be
83# written into the same directory.
84argv = ['nix-instantiate', '--eval', '--json', '-A', 'crosvm.meta.position']
85position = json.loads(subprocess.check_output(argv).decode('utf-8'))
86filename = re.match(r'[^:]*', position)[0]
87
88# Finally, write the output.
89with open(dirname(filename) + '/upstream-info.json', 'w') as out:
90 json.dump(data, out, indent=2)
91 out.write('\n')