recipe engine: add remote_run command

recipes.py

 #!/usr/bin/env python
 # Copyright 2015 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.
 
 """Tool to interact with recipe repositories.
 
 This tool operates on the nearest ancestor directory containing an
 infra/config/recipes.cfg.
 """
@@ skipping 129 matching lines @@
         properties, stream_engine,
         step_runner.SubprocessStepRunner(stream_engine),
         universe=universe)
 
   finally:
     os.chdir(old_cwd)
 
   return handle_recipe_return(ret, args.output_result_json, stream_engine)
 
 
+def remote_run(args):
+  from recipe_engine import remote_run
+
+  return remote_run.main(args)
+
+
 def autoroll(args):
   from recipe_engine import autoroll
 
   repo_root, config_file = get_package_config(args)
 
   return autoroll.main(args, repo_root, config_file)
 
 
 class ProjectOverrideAction(argparse.Action):
   def __call__(self, parser, namespace, values, option_string=None):
@@ skipping 120 matching lines @@
       help='The file to write the JSON serialized returned value \
             of the recipe to')
   run_p.add_argument(
       'recipe',
       help='The recipe to execute')
   run_p.add_argument(
       'props', nargs=argparse.REMAINDER,
       help='A list of property pairs; e.g. mastername=chromium.linux '
            'issue=12345')
 
+  remote_run_p = subp.add_parser(
+      'remote_run',
+      description='Run a recipe from specified repo and revision')
+  remote_run_p.set_defaults(command='remote_run')
+  remote_run_p.add_argument(
+      '--repository', required=True,
+      help='URL of a git repository to fetch')
+  remote_run_p.add_argument(
+      '--revision', default='FETCH_HEAD',
+      help='Git commit hash to check out')
+  remote_run_p.add_argument(
+      '--workdir',
+      help='The working directory of repo checkout')
+  remote_run_p.add_argument(
+      'run_args', nargs='*',
+      help='Arguments to pass to fetched repo\'s recipes.py run')
+
   autoroll_p = subp.add_parser(
       'autoroll',
       help='Roll dependencies of a recipe package forward (implies fetch)')
   autoroll_p.set_defaults(command='autoroll')
   autoroll_p.add_argument(
       '--output-json',
       help='A json file to output information about the roll to.')
 
   depgraph_p = subp.add_parser(
       'depgraph',
@@ skipping 28 matching lines @@
   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.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)
 
   try:
     # TODO(phajdan.jr): gracefully handle inconsistent deps when rolling.
     # This fails if the starting point does not have consistent dependency
     # graph. When performing an automated roll, it'd make sense to attempt
     # to automatically find a consistent state, rather than bailing out.
     # Especially that only some subcommands refer to package_deps.
     package_deps = package.PackageDeps.create(
         repo_root, config_file, allow_fetch=not args.no_fetch,
@@ skipping 46 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)