# Copyright 2019 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Sends notifications after automatic exports.
Automatically comments on a Gerrit CL when its corresponding PR fails the Taskcluster check. In
other words, surfaces cross-browser WPT regressions from Github to Gerrit.
Design doc: https://docs.google.com/document/d/1MtdbUcWBDZyvmV0FOdsTWw_Jv16YtE6KW5BnnCVYX4c
"""
import logging
from typing import Mapping
from blinkpy.w3c.common import WPT_REVISION_FOOTER, WPT_GH_URL
from blinkpy.w3c.gerrit import GerritError
from blinkpy.w3c.wpt_github import GitHubError
_log = logging.getLogger(__name__)
RELEVANT_TASKCLUSTER_CHECKS = [
'wpt-chrome-dev-stability', 'wpt-firefox-nightly-stability', 'lint',
'infrastructure/ tests'
]
class ExportNotifier(object):
def __init__(self, host, wpt_github, gerrit, dry_run=True):
self.host = host
self.wpt_github = wpt_github
self.gerrit = gerrit
self.dry_run = dry_run
def main(self) -> Mapping[str, 'PRStatusInfo']:
"""Surfaces relevant Taskcluster check failures to Gerrit through comments.
Returns:
A map from change IDs to statuses for failed PRs.
Raises:
ExportNotifierError: If the export notification somehow failed.
"""
prs_by_change_id = {}
try:
_log.info('Searching for recent failing chromium exports.')
prs = self.wpt_github.recent_failing_chromium_exports()
except GitHubError as e:
raise ExportNotifierError('Surfacing Taskcluster failures '
f'could not be completed: {e}') from e
if len(prs) > 100:
raise ExportNotifierError(
f'Too many open failing PRs: {len(prs)}; abort.')
_log.info('Found %d failing PRs.', len(prs))
for pr in prs:
check_runs = self.get_check_runs(pr.number)
if not check_runs:
continue
checks_results = self.get_relevant_failed_taskcluster_checks(check_runs)
if not checks_results:
continue
gerrit_id = self.wpt_github.extract_metadata(
'Change-Id: ', pr.body)
if not gerrit_id:
_log.error('Can not retrieve Change-Id for %s.', pr.number)
continue
gerrit_sha = self.wpt_github.extract_metadata(
WPT_REVISION_FOOTER, pr.body)
prs_by_change_id[gerrit_id] = PRStatusInfo(checks_results,
pr.number, gerrit_sha)
self.process_failing_prs(prs_by_change_id)
return prs_by_change_id
def get_check_runs(self, number):
"""Retrieves check runs through a PR number.
Returns:
A JSON array representing the check runs for the HEAD of this PR.
"""
try:
branch = self.wpt_github.get_pr_branch(number)
check_runs = self.wpt_github.get_branch_check_runs(branch)
except GitHubError as e:
_log.error(str(e))
return None
return check_runs
def process_failing_prs(self, prs_by_change_id):
"""Processes and comments on CLs with failed Tackcluster checks."""
_log.info('Processing %d CLs with failed Taskcluster checks.',
len(prs_by_change_id))
for change_id, pr_status_info in prs_by_change_id.items():
_log.info('Change-Id: %s', change_id)
try:
cl = self.gerrit.query_cl_comments_and_revisions(change_id)
has_commented = self.has_latest_taskcluster_status_commented(
cl.messages, pr_status_info)
if has_commented:
_log.info('Comment is up-to-date. Nothing to do here.')
continue
revision = cl.revisions.get(pr_status_info.gerrit_sha)
if revision:
cl_comment = pr_status_info.to_gerrit_comment(
revision['_number'])
else:
cl_comment = pr_status_info.to_gerrit_comment()
if self.dry_run:
_log.info('[dry_run] Would have commented on CL %s\n',
change_id)
_log.debug('Comments are:\n%s\n', cl_comment)
else:
_log.info('Commenting on CL %s\n', change_id)
cl.post_comment(cl_comment)
except GerritError as e:
_log.error('Could not process Gerrit CL %s: %s', change_id,
str(e))
continue
def has_latest_taskcluster_status_commented(self, messages,
pr_status_info):
"""Determines if the Taskcluster status has already been commented on the messages of a CL.
Args:
messages: messagese of a CL in JSON Array format, in chronological order.
pr_status_info: PRStatusInfo object.
"""
for message in reversed(messages):
cl_gerrit_sha = PRStatusInfo.get_gerrit_sha_from_comment(
message['message'])
if cl_gerrit_sha:
_log.debug('Found latest comment: %s', message['message'])
return cl_gerrit_sha == pr_status_info.gerrit_sha
return False
def get_relevant_failed_taskcluster_checks(self, check_runs):
"""Filters relevant failed Taskcluster checks from check_runs.
Args:
check_runs: A JSON array; e.g. "check_runs" in
https://developer.github.com/v3/checks/runs/#response-3
Returns:
A dictionary where keys are names of the Taskcluster checks and values
are URLs to the Taskcluster checks' results.
"""
checks_results = {}
for check in check_runs:
if (check['conclusion'] == 'failure') and (
check['name'] in RELEVANT_TASKCLUSTER_CHECKS):
result_url = '{}runs/{}'.format(WPT_GH_URL, check['id'])
checks_results[check['name']] = result_url
return checks_results
class ExportNotifierError(Exception):
"""Represents an unsuccessful notification attempt."""
class PRStatusInfo(object):
CL_SHA_TAG = 'Gerrit CL SHA: '
PATCHSET_TAG = 'Patchset Number: '
def __init__(self, checks_results, pr_number, gerrit_sha=None):
self._checks_results = checks_results
self.pr_number = pr_number
if gerrit_sha:
self._gerrit_sha = gerrit_sha
else:
self._gerrit_sha = 'Latest'
@property
def gerrit_sha(self):
return self._gerrit_sha
@staticmethod
def get_gerrit_sha_from_comment(comment):
for line in comment.splitlines():
if line.startswith(PRStatusInfo.CL_SHA_TAG):
return line[len(PRStatusInfo.CL_SHA_TAG):]
return None
def _checks_results_as_comment(self):
comment = ''
for check, url in self._checks_results.items():
comment += '\n%s (%s)' % (check, url)
return comment
def to_gerrit_comment(self, patchset=None):
comment = (
'The exported PR, {}, has failed the following check(s) '
'on GitHub:\n{}\n\nThese failures will block the export. '
'They may represent new or existing problems; please take '
'a look at the output and see if it can be fixed. '
'Unresolved failures will be looked at by the Ecosystem-Infra '
'sheriff after this CL has been landed in Chromium; if you '
'need earlier help please contact [email protected].\n\n'
'Any suggestions to improve this service are welcome; '
'crbug.com/1027618.').format(
'%spull/%d' % (WPT_GH_URL, self.pr_number),
self._checks_results_as_comment())
comment += ('\n\n{}{}').format(PRStatusInfo.CL_SHA_TAG,
self._gerrit_sha)
if patchset is not None:
comment += ('\n{}{}').format(PRStatusInfo.PATCHSET_TAG, patchset)
return comment
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