recipe engine: add remote_run command

recipe_engine/remote_run.py

Index: recipe_engine/remote_run.py
diff --git a/recipe_engine/remote_run.py b/recipe_engine/remote_run.py
new file mode 100644
index 0000000000000000000000000000000000000000..76251a8d0654c82146384143f8111bbe19981f7d
--- /dev/null
+++ b/recipe_engine/remote_run.py
@@ -0,0 +1,44 @@
+# Copyright 2016 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.
+
+from __future__ import print_function
+
+import logging
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+
+from recipe_engine import fetch
+from recipe_engine import package
+
+
+def real_main(args):
+  checkout_dir = os.path.join(args.workdir, 'checkout')
+  fetch.fetch_from_git(args.repository, args.revision, checkout_dir,
+                       allow_fetch=True)
+  proto_file = package.ProtoFile(
+      package.InfraRepoConfig().to_recipes_cfg(checkout_dir))
+  cmd = [

[martiniss, 2016/05/20 17:56:31]

My original design here had been to just do the fetch, and then return from here
and proceed with the regular logic in recipes.py. So, there wouldn't be a
subprocess call here. 

Not sure exactly if it's worth doing that, which might add some complication,
and a bit of confusion to the command logic in recipes.py, but just mentioning
it in case you hadn't thought of it.

[Paweł Hajdan Jr., 2016/05/20 21:59:57]

Given it's going to be the entry point replacing kitchen, I think this has to be
inside this command. There's no "something else" to call the real run later.
Does that make sense? :)

+      sys.executable,
+      os.path.join(checkout_dir, proto_file.read().recipes_path, 'recipes.py'),

[iannucci1, 2016/05/20 18:04:22]

s/proto_file/recipes_cfg ?

proto_file will get confusing if we ever use proto for anything else (which we
probably will)

[Paweł Hajdan Jr., 2016/05/20 21:59:57]

Done.

+      'run'
+  ] + args.run_args
+  logging.info('Running %r', cmd)
+  return subprocess.call(cmd)
+
+
+def main(args):
+  workdir_tempdir = False
+  if not args.workdir:
+    workdir_tempdir = True
+    args.workdir = tempfile.mkdtemp(prefix='recipe_engine_remote_run_')
+    logging.info('Created temporary workdir %s', args.workdir)
+
+  try:
+    return real_main(args)
+  finally:
+    if workdir_tempdir:
+      shutil.rmtree(args.workdir)

[iannucci1, 2016/05/20 18:04:22]

ignore errors?

[Paweł Hajdan Jr., 2016/05/20 21:59:57]

Done.