add basic bootstrap for coverage

recipes.py

 #!/usr/bin/env python
 # Copyright 2015 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """Tool to interact with recipe repositories.
 
 This tool operates on the nearest ancestor directory containing an
 infra/config/recipes.cfg.
 """
@@ skipping 204 matching lines @@
 
   if args.recipes_dir:
     print package_spec.recipes_path
 
 
 def main():
   from recipe_engine import package
 
   # Super-annoyingly, we need to manually parse for simulation_test since
   # argparse is bonkers and doesn't allow us to forward --help to subcommands.
+  # Save old_args for if we're using bootstrap
+  original_sys_argv = sys.argv[:]
   if 'simulation_test' in sys.argv:
     index = sys.argv.index('simulation_test')
     sys.argv = sys.argv[:index+1] + [json.dumps(sys.argv[index+1:])]
 
   parser = argparse.ArgumentParser(
       description='Interact with the recipe system.')
 
   parser.add_argument(
       '--package',
       help='Path to recipes.cfg of the recipe package to operate on'
         ', usually in infra/config/recipes.cfg')
   parser.add_argument(
       '--deps-path',
       help='Path where recipe engine dependencies will be extracted.')
   parser.add_argument(
       '--verbose', '-v', action='store_true',
       help='Increase logging verboisty')
   # TODO(phajdan.jr): Figure out if we need --no-fetch; remove if not.
   parser.add_argument(
       '--no-fetch', action='store_true',
       help='Disable automatic fetching')
   parser.add_argument(
       '--bootstrap-script',
       help='Path to the script used to bootstrap this tool (internal use only)')
   parser.add_argument('-O', '--project-override', metavar='ID=PATH',
       action=ProjectOverrideAction,
       help='Override a project repository path with a local one.')
+  parser.add_argument(
+      '--use-bootstrap', action='store_true',
+      help='Use bootstrap/bootstrap.py to create a isolated python virtualenv'
+           ' with required python dependencies.')
 
   subp = parser.add_subparsers()
 
   fetch_p = subp.add_parser(
       'fetch',
       description='Fetch and update dependencies.')
   fetch_p.set_defaults(command='fetch')
 
   simulation_test_p = subp.add_parser(
     'simulation_test',
@@ skipping 107 matching lines @@
   info_p = subp.add_parser(
       'info',
       description='Query information about the current recipe package')
   info_p.set_defaults(command='info')
   info_p.add_argument(
       '--recipes-dir', action='store_true',
       help='Get the subpath where the recipes live relative to repository root')
 
   args = parser.parse_args()
 
+  if args.use_bootstrap and not os.environ.pop('RECIPES_RUN_BOOTSTRAP', None):
+    subprocess.check_call(
+        [sys.executable, 'bootstrap/bootstrap.py', '--deps-file',
+         'bootstrap/deps.pyl', 'ENV'],
+        cwd=os.path.dirname(os.path.realpath(__file__)))
+
+    os.environ['RECIPES_RUN_BOOTSTRAP'] = '1'
+    args = sys.argv
+    return subprocess.call(
+        ['ENV/bin/python'] + original_sys_argv,
+        cwd=os.path.dirname(os.path.realpath(__file__)))
+
   if args.verbose:
     logging.getLogger().setLevel(logging.INFO)
 
   # Commands which do not require config_file, package_deps, and other objects
   # initialized later.
   if args.command == 'remote_run':
     return remote_run(args)
 
   repo_root, config_file = get_package_config(args)
 
@@ skipping 54 matching lines @@
   ret = main()
   if not isinstance(ret, int):
     if ret is None:
       ret = 0
     else:
       print >> sys.stderr, ret
       ret = 1
   sys.stdout.flush()
   sys.stderr.flush()
   os._exit(ret)