tools/checkteamtags/checkteamtags.py

#!/usr/bin/env python
# Copyright (c) 2017 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Makes sure OWNERS files have consistent TEAM and COMPONENT tags."""


import json
import logging
import optparse
import os
import re
import sys
import urllib2

from collections import defaultdict

from owners_file_tags import parse


DEFAULT_MAPPING_URL = \
    'https://storage.googleapis.com/chromium-owners/component_map.json'

# Represent tags that may be found in OWNERS files.
_COMPONENT = 'COMPONENT'
_TEAM = 'TEAM'

# Represents the pattern of a line that contains a TEAM or COMPONENT tag. Note
# that matching lines may not have valid formatting. For example, if {} is
# replaced with TEAM, the line ' #TEAMS :some-team@chromium.org' matches the
# pattern; however, the correct formatting is '# TEAM: some-team@chromium.org'.
LINE_PATTERN = '.*#\s*{}.*:.*'

def _get_entries(lines, tag):
  """Returns a line for the given tag, e.g. '# TEAM: some-team@google.com'.

  Also, validates the tag's prefix format.

  Args:
    lines: A list of lines from which to extract information, e.g.
      ['liz@google.com', '# COMPONENT: UI', '# TEAM: ui-team@chromium.org'].
    tag: The string tag denoting the entry for which to extract information,
      e.g. 'COMPONENT'.

  Raises:
    ValueError: Raised if (A) a line matches the specified line pattern, but
    does not match the  the prefix pattern. This can happen, e.g., if a line is
    '#TEAM: some-team@google.com', which is missing a space between # and TEAM.
    Also, raised if (B) there are multiple lines matching the line pattern.
    This can happen if there are, e.g. two team lines.
  """
  line_pattern = re.compile(LINE_PATTERN.format(tag))
  entries = [line for line in lines if line_pattern.match(line)]

  if not entries:
    return None

  if len(entries) == 1:
    if re.match('^# {}: .*$'.format(tag), entries[0]):
      return entries[0]
    raise ValueError(
        '{} has an invalid prefix. Use \'# {}: \''.format(entries[0], tag))

  raise ValueError('Contains more than one {} per directory'.format(tag))


def rel_and_full_paths(root, owners_path):
  if root:
    full_path = os.path.join(root, owners_path)
    rel_path = owners_path
  else:
    full_path = os.path.abspath(owners_path)
    rel_path = os.path.relpath(owners_path)
  return rel_path, full_path


def validate_mappings(options, args):
  """Ensure team/component mapping remains consistent after patch.

  The main purpose of this check is to notify the user if any edited (or added)
  team tag makes a component map to multiple teams.

  Args:
    options: Command line options from optparse
    args: List of paths to affected OWNERS files
  Returns:
    A string containing the details of any multi-team per component.
  """
  mappings_file = json.load(urllib2.urlopen(options.current_mapping_url))
  new_dir_to_component = mappings_file.get('dir-to-component', {})
  new_dir_to_team = mappings_file.get('dir-to-team', {})

  affected = {}
  deleted = []
  affected_components = set()

  # Parse affected OWNERS files
  for f in args:
    rel, full = rel_and_full_paths(options.root, f)
    if os.path.exists(full):
      affected[os.path.dirname(rel)] = parse(full)
    else:
      deleted.append(os.path.dirname(rel))

  # Update component mapping with current changes.
  for rel_path, tags in affected.iteritems():
    component = tags.get('component')
    team = tags.get('team')
    os_tag = tags.get('os')
    if component:
      if os_tag:
        component = '%s(%s)' % (component, os_tag)
      new_dir_to_component[rel_path] = component
      affected_components.add(component)
    elif rel_path in new_dir_to_component:
      del new_dir_to_component[rel_path]
    if team:
      new_dir_to_team[rel_path] = team
    elif rel_path in new_dir_to_team:
      del new_dir_to_team[rel_path]
  for deleted_dir in deleted:
    if deleted_dir in new_dir_to_component:
      del new_dir_to_component[deleted_dir]
    if deleted_dir in new_dir_to_team:
      del new_dir_to_team[deleted_dir]

  # For the components affected by this patch, compute the directories that map
  # to it.
  affected_component_to_dirs = {}
  for d, component in new_dir_to_component.iteritems():
    if component in affected_components:
      affected_component_to_dirs.setdefault(component, [])
      affected_component_to_dirs[component].append(d)

  # Convert component->[dirs], dir->team to component->[teams].
  affected_component_to_teams = {
      component: list(set([
          new_dir_to_team[d]
          for d in dirs
          if d in new_dir_to_team
      ])) for component, dirs in affected_component_to_dirs.iteritems()
  }

  # Perform cardinality check.
  warnings = ''
  for component, teams in affected_component_to_teams.iteritems():
    if len(teams) > 1:
      warnings += '\nComponent %s will map to %s' % (
          component, ', '.join(teams))
  if warnings:
    warnings = ('Are you sure these are correct? After landing this patch:%s'
                % warnings)

  return warnings


def check_owners(rel_path, full_path):
  """Component and Team check in OWNERS files. crbug.com/667954"""
  def result_dict(error):
    return {
      'error': error,
      'full_path': full_path,
      'rel_path': rel_path,
    }

  if not os.path.exists(full_path):
    return

  with open(full_path) as f:
    owners_file_lines = f.readlines()

  try:
    component_line = _get_entries(owners_file_lines, _COMPONENT)
    team_line = _get_entries(owners_file_lines, _TEAM)
  except ValueError as error:
    return result_dict(str(error))

  if component_line:
    component = component_line.split(':')[1]
    if not component:
      return result_dict('Has COMPONENT line but no component name')
    # Check for either of the following formats:
    #   component1, component2, ...
    #   component1,component2,...
    #   component1 component2 ...
    component_count = max(
        len(component.strip().split()),
        len(component.strip().split(',')))
    if component_count > 1:
      return result_dict('Has more than one component name')
    # TODO(robertocn): Check against a static list of valid components,
    # perhaps obtained from monorail at the beginning of presubmit.

  if team_line:
    team_entry_parts = team_line.split('@')
    if len(team_entry_parts) != 2:
      return result_dict('Has TEAM line, but not exactly 1 team email')
  # TODO(robertocn): Raise a warning if only one of (COMPONENT, TEAM) is
  # present.


def main():
  usage = """Usage: python %prog [--root <dir>] <owners_file1> <owners_file2>...
  owners_fileX  specifies the path to the file to check, these are expected
                to be relative to the root directory if --root is used.

Examples:
  python %prog --root /home/<user>/chromium/src/ tools/OWNERS v8/OWNERS
  python %prog /home/<user>/chromium/src/tools/OWNERS
  python %prog ./OWNERS
  """

  parser = optparse.OptionParser(usage=usage)
  parser.add_option(
      '--root', help='Specifies the repository root.')
  parser.add_option(
      '-v', '--verbose', action='count', default=0, help='Print debug logging')
  parser.add_option(
      '--bare',
      action='store_true',
      default=False,
      help='Prints the bare filename triggering the checks')
  parser.add_option(
      '--current_mapping_url', default=DEFAULT_MAPPING_URL,
      help='URL for existing dir/component and component/team mapping')
  parser.add_option('--json', help='Path to JSON output file')
  options, args = parser.parse_args()

  levels = [logging.ERROR, logging.INFO, logging.DEBUG]
  logging.basicConfig(level=levels[min(len(levels) - 1, options.verbose)])

  errors = filter(None, [check_owners(*rel_and_full_paths(options.root, f))
                         for f in args])

  warnings = None
  if not errors:
    warnings = validate_mappings(options, args)

  if options.json:
    with open(options.json, 'w') as f:
      json.dump(errors, f)

  if errors:
    if options.bare:
      print '\n'.join(e['full_path'] for e in errors)
    else:
      print '\nFAILED\n'
      print '\n'.join('%s: %s' % (e['full_path'], e['error']) for e in errors)
    return 1
  if not options.bare:
    if warnings:
      print warnings
  return 0


if '__main__' == __name__:
  sys.exit(main())