Update recipes.py to f605e5c0bc2e748170ca851383cb552c7225316b

This will enable it to be compatible with both the textpb and
upcoming jsonpb form of recipes.cfg.

BUG=699379

Change-Id: Iafa3d959190648eca4fa864aaa79430759e568fe
Reviewed-on: https://chromium-review.googlesource.com/455585
Reviewed-by: Nodir Turakulov <nodir@chromium.org>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>

recipes.py

@@ -28,6 +28,7 @@ BOOTSTRAP_VERSION = 1
 
 import argparse
 import ast
+import json
 import logging
 import random
 import re
@@ -36,8 +37,71 @@ import sys
 import time
 import traceback
 
+from cStringIO import StringIO
 
-def parse_protobuf(fh):
+
+def parse(repo_root, recipes_cfg_path):
+  """Parse is transitional code which parses a recipes.cfg file as either jsonpb
+  or as textpb.
+
+  Args:
+    repo_root (str) - native path to the root of the repo we're trying to run
+      recipes for.
+    recipes_cfg_path (str) - native path to the recipes.cfg file to process.
+
+  Returns (as tuple):
+    engine_url (str) - the url to the engine repo we want to use.
+    engine_revision (str) - the git revision for the engine to get.
+    engine_subpath (str) - the subdirectory in the engine repo we should use to
+      find it's recipes.py entrypoint. This is here for completeness, but will
+      essentially always be empty. It would be used if the recipes-py repo was
+      merged as a subdirectory of some other repo and you depended on that
+      subdirectory.
+    recipes_path (str) - native path to where the recipes live inside of the
+      current repo (i.e. the folder containing `recipes/` and/or
+      `recipe_modules`)
+  """
+  with open(recipes_cfg_path, 'rU') as fh:
+    data = fh.read()
+
+  if data.lstrip().startswith('{'):
+    pb = json.loads(data)
+    engine = next(
+      (d for d in pb['deps'] if d['project_id'] == 'recipe_engine'), None)
+    if engine is None:
+      raise ValueError('could not find recipe_engine dep in %r'
+                       % recipes_cfg_path)
+    engine_url = engine['url']
+    engine_revision = engine['revision']
+    engine_subpath = engine.get('path_override', '')
+    recipes_path = pb.get('recipes_path', '')
+  else:
+    def get_unique(things):
+      if len(things) == 1:
+        return things[0]
+      elif len(things) == 0:
+        raise ValueError("Expected to get one thing, but dinna get none.")
+      else:
+        logging.warn('Expected to get one thing, but got a bunch: %s\n%s' %
+                     (things, traceback.format_stack()))
+        return things[0]
+
+    protobuf = parse_textpb(StringIO(data))
+
+    engine_buf = get_unique([
+        b for b in protobuf.get('deps', [])
+        if b.get('project_id') == ['recipe_engine'] ])
+    engine_url = get_unique(engine_buf['url'])
+    engine_revision = get_unique(engine_buf['revision'])
+    engine_subpath = (get_unique(engine_buf.get('path_override', ['']))
+                      .replace('/', os.path.sep))
+    recipes_path = get_unique(protobuf.get('recipes_path', ['']))
+
+  recipes_path = os.path.join(repo_root, recipes_path.replace('/', os.path.sep))
+  return engine_url, engine_revision, engine_subpath, recipes_path
+
+
+def parse_textpb(fh):
   """Parse the protobuf text format just well enough to understand recipes.cfg.
 
   We don't use the protobuf library because we want to be as self-contained
@@ -75,7 +139,7 @@ def parse_protobuf(fh):
 
     m = re.match(r'(\w+)\s*{', line)
     if m:
-      subparse = parse_protobuf(fh)
+      subparse = parse_textpb(fh)
       ret.setdefault(m.group(1), []).append(subparse)
       continue
 
@@ -89,17 +153,6 @@ def parse_protobuf(fh):
   return ret
 
 
-def get_unique(things):
-  if len(things) == 1:
-    return things[0]
-  elif len(things) == 0:
-    raise ValueError("Expected to get one thing, but dinna get none.")
-  else:
-    logging.warn('Expected to get one thing, but got a bunch: %s\n%s' %
-                 (things, traceback.format_stack()))
-    return things[0]
-
-
 def _subprocess_call(argv, **kwargs):
   logging.info('Running %r', argv)
   return subprocess.call(argv, **kwargs)
@@ -146,37 +199,28 @@ def main():
       os.path.join(os.path.dirname(__file__), REPO_ROOT))
   recipes_cfg_path = os.path.join(repo_root, RECIPES_CFG)
 
-  with open(recipes_cfg_path, 'rU') as fh:
-    protobuf = parse_protobuf(fh)
-
-  engine_buf = get_unique([
-      b for b in protobuf.get('deps', [])
-      if b.get('project_id') == ['recipe_engine'] ])
-  engine_url = get_unique(engine_buf['url'])
-  engine_revision = get_unique(engine_buf['revision'])
-  engine_subpath = (get_unique(engine_buf.get('path_override', ['']))
-                    .replace('/', os.path.sep))
-
-  recipes_path = os.path.join(repo_root,
-      get_unique(protobuf.get('recipes_path', [''])).replace('/', os.path.sep))
+  engine_url, engine_revision, engine_subpath, recipes_path = parse(
+    repo_root, recipes_cfg_path)
+
   deps_path = os.path.join(recipes_path, '.recipe_deps')
   engine_path = find_engine_override(sys.argv[1:])
   if not engine_path:
     # Ensure that we have the recipe engine cloned.
-    engine_path = os.path.join(deps_path, 'recipe_engine')
+    engine_root_path = os.path.join(deps_path, 'recipe_engine')
+    engine_path = os.path.join(engine_root_path, engine_subpath)
     def ensure_engine():
       if not os.path.exists(deps_path):
         os.makedirs(deps_path)
-      if not os.path.exists(engine_path):
-        _subprocess_check_call([git, 'clone', engine_url, engine_path])
+      if not os.path.exists(engine_root_path):
+        _subprocess_check_call([git, 'clone', engine_url, engine_root_path])
 
       needs_fetch = _subprocess_call(
           [git, 'rev-parse', '--verify', '%s^{commit}' % engine_revision],
-          cwd=engine_path, stdout=open(os.devnull, 'w'))
+          cwd=engine_root_path, stdout=open(os.devnull, 'w'))
       if needs_fetch:
-        _subprocess_check_call([git, 'fetch'], cwd=engine_path)
+        _subprocess_check_call([git, 'fetch'], cwd=engine_root_path)
       _subprocess_check_call(
-          [git, 'checkout', '--quiet', engine_revision], cwd=engine_path)
+          [git, 'checkout', '--quiet', engine_revision], cwd=engine_root_path)
 
     try:
       ensure_engine()
@@ -190,7 +234,7 @@ def main():
   args = ['--package', recipes_cfg_path] + sys.argv[1:]
   return _subprocess_call([
       sys.executable, '-u',
-      os.path.join(engine_path, engine_subpath, 'recipes.py')] + args)
+      os.path.join(engine_path, 'recipes.py')] + args)
 
 if __name__ == '__main__':
   sys.exit(main())