runbot/runbot_merge/github.py
Xavier Morel af8c62e4ad [FIX] runbot_merge: better handle targets being branch-protected
If a staging covers multiple repositories and there's a fast-forward
issue on any but the first repo/target, runbot_merge attempted to
revert the commits it had fast-forwarded on the previous repos.

This doesn't work when branch-protection is active, unless runbot_merge
is a repository administrator (and branch protection is not configured
to apply to those): reverting is done by push-forcing the original head
back onto the ref, which branch-protection unconditionally precludes.

This commit does not entirely fix the race condition (it does not look
like github provides any way to do that), but it should significantly
reduce the race-condition window as it performs a semi-wet run of the
fast-forward process on the tmp branches before actually updating the
targets. That way the only remaining breakage should be when somebody
pushes on repositories 1.. between the test-FF on tmp branches and the
actual fast forward.

While at it, updated the github API thing to *always* dump the JSON body
on an error response, if the content-type is json.
2018-10-10 10:50:21 +02:00

218 lines
7.7 KiB
Python

import collections
import itertools
import json as json_
import logging
import requests
from odoo.tools import topological_sort
from . import exceptions
_logger = logging.getLogger(__name__)
class GH(object):
def __init__(self, token, repo):
self._url = 'https://api.github.com'
self._repo = repo
session = self._session = requests.Session()
session.headers['Authorization'] = 'token {}'.format(token)
def __call__(self, method, path, params=None, json=None, check=True):
"""
:type check: bool | dict[int:Exception]
"""
r = self._session.request(
method,
'{}/repos/{}/{}'.format(self._url, self._repo, path),
params=params,
json=json
)
if check:
if isinstance(check, collections.Mapping):
exc = check.get(r.status_code)
if exc:
raise exc(r.content)
if r.status_code >= 400 and r.headers.get('content-type', '').startswith('application/javascript'):
raise requests.HTTPError(
json_.dumps(r.json(), indent=4),
response=r
)
r.raise_for_status()
return r
def head(self, branch):
d = self('get', 'git/refs/heads/{}'.format(branch)).json()
assert d['ref'] == 'refs/heads/{}'.format(branch)
assert d['object']['type'] == 'commit'
_logger.debug("head(%s, %s) -> %s", self._repo, branch, d['object']['sha'])
return d['object']['sha']
def commit(self, sha):
c = self('GET', 'git/commits/{}'.format(sha)).json()
_logger.debug('commit(%s, %s) -> %s', self._repo, sha, shorten(c['message']))
return c
def comment(self, pr, message):
self('POST', 'issues/{}/comments'.format(pr), json={'body': message})
_logger.debug('comment(%s, %s, %s)', self._repo, pr, shorten(message))
def close(self, pr, message):
self.comment(pr, message)
self('PATCH', 'pulls/{}'.format(pr), json={'state': 'closed'})
def change_tags(self, pr, from_, to_):
to_add, to_remove = to_ - from_, from_ - to_
for t in to_remove:
r = self('DELETE', 'issues/{}/labels/{}'.format(pr, t), check=False)
# successful deletion or attempt to delete a tag which isn't there
# is fine, otherwise trigger an error
if r.status_code not in (200, 404):
r.raise_for_status()
if to_add:
self('POST', 'issues/{}/labels'.format(pr), json=list(to_add))
_logger.debug('change_tags(%s, %s, remove=%s, add=%s)', self._repo, pr, to_remove, to_add)
def fast_forward(self, branch, sha):
try:
self('patch', 'git/refs/heads/{}'.format(branch), json={'sha': sha})
_logger.debug('fast_forward(%s, %s, %s) -> OK', self._repo, branch, sha)
except requests.HTTPError:
_logger.debug('fast_forward(%s, %s, %s) -> ERROR', self._repo, branch, sha, exc_info=True)
raise exceptions.FastForwardError()
def set_ref(self, branch, sha):
# force-update ref
r = self('patch', 'git/refs/heads/{}'.format(branch), json={
'sha': sha,
'force': True,
}, check=False)
if r.status_code == 200:
_logger.debug('set_ref(update, %s, %s, %s) -> OK', self._repo, branch, sha)
return
# 422 makes no sense but that's what github returns, leaving 404 just
# in case
if r.status_code in (404, 422):
# fallback: create ref
r = self('post', 'git/refs', json={
'ref': 'refs/heads/{}'.format(branch),
'sha': sha,
}, check=False)
if r.status_code == 201:
_logger.debug('set_ref(create, %s, %s, %s) -> OK', self._repo, branch, sha)
return
raise AssertionError("{}: {}".format(r.status_code, r.json()))
def merge(self, sha, dest, message):
r = self('post', 'merges', json={
'base': dest,
'head': sha,
'commit_message': message,
}, check={409: exceptions.MergeError})
try:
r = r.json()
except Exception:
raise exceptions.MergeError("Got non-JSON reponse from github: %s %s (%s)" % (r.status_code, r.reason, r.content.decode('iso-8859-1')))
_logger.debug("merge(%s, %s, %s) -> %s", self._repo, dest, shorten(message), r['sha'])
return dict(r['commit'], sha=r['sha'])
def rebase(self, pr, dest, reset=False, commits=None):
""" Rebase pr's commits on top of dest, updates dest unless ``reset``
is set.
Returns the hash of the rebased head.
"""
original_head = self.head(dest)
if commits is None:
commits = self.commits(pr)
assert commits, "can't rebase a PR with no commits"
for c in commits:
assert len(c['parents']) == 1, "can't rebase commits with more than one parent"
tmp_msg = 'temp rebasing PR %s (%s)' % (pr, c['sha'])
c['new_tree'] = self.merge(c['sha'], dest, tmp_msg)['tree']['sha']
prev = original_head
for c in commits:
copy = self('post', 'git/commits', json={
'message': c['commit']['message'],
'tree': c['new_tree'],
'parents': [prev],
'author': c['commit']['author'],
'committer': c['commit']['committer'],
}, check={409: exceptions.MergeError}).json()
prev = copy['sha']
if reset:
self.set_ref(dest, original_head)
else:
self.set_ref(dest, prev)
_logger.debug('%s, %s, %s, reset=%s, commits=%s) -> %s',
self._repo, pr, dest, reset, commits and len(commits),
prev)
# prev is updated after each copy so it's the rebased PR head
return prev
# fetch various bits of issues / prs to load them
def pr(self, number):
return (
self('get', 'issues/{}'.format(number)).json(),
self('get', 'pulls/{}'.format(number)).json()
)
def comments(self, number):
for page in itertools.count(1):
r = self('get', 'issues/{}/comments'.format(number), params={'page': page})
yield from r.json()
if not r.links.get('next'):
return
def reviews(self, number):
for page in itertools.count(1):
r = self('get', 'pulls/{}/reviews'.format(number), params={'page': page})
yield from r.json()
if not r.links.get('next'):
return
def commits_lazy(self, pr):
for page in itertools.count(1):
r = self('get', 'pulls/{}/commits'.format(pr), params={'page': page})
yield from r.json()
if not r.links.get('next'):
return
def commits(self, pr):
""" Returns a PR's commits oldest first (that's what GH does &
is what we want)
"""
commits = list(self.commits_lazy(pr))
# map shas to the position the commit *should* have
idx = {
c: i
for i, c in enumerate(topological_sort({
c['sha']: [p['sha'] for p in c['parents']]
for c in commits
}))
}
return sorted(commits, key=lambda c: idx[c['sha']])
def statuses(self, h):
r = self('get', 'commits/{}/status'.format(h)).json()
return [{
'sha': r['sha'],
**s,
} for s in r['statuses']]
def shorten(s):
if not s:
return s
line1 = s.split('\n', 1)[0]
if len(line1) < 50:
return line1
return line1[:47] + '...'