[recipes.py] move common arg parsing to separate module.

recipe_engine/common_args.py

Index: recipe_engine/common_args.py
diff --git a/recipe_engine/common_args.py b/recipe_engine/common_args.py
new file mode 100644
index 0000000000000000000000000000000000000000..18292de777ecc4ba17c3443357448563afd05f09
--- /dev/null
+++ b/recipe_engine/common_args.py
@@ -0,0 +1,128 @@
+# Copyright 2017 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.
+
+"""Common arguments to the various recipes.py subcommands.
+
+This is in a separate file for recipes.py for testing purposes.
+"""
+
+import json
+import logging
+import os
+
+from . import package_io
+
+from . import env
+
+import argparse  # this is vendored
+
+from . import arguments_pb2
+
+from google.protobuf import json_format as jsonpb
+
+
+def add_common_args(parser):
+  class ProjectOverrideAction(argparse.Action):
+    def __call__(self, parser, namespace, values, option_string=None):
+      p = values.split('=', 2)
+      if len(p) != 2:
+        raise ValueError('Override must have the form: repo=path')
+      project_id, path = p
+
+      v = getattr(namespace, self.dest, None)
+      if v is None:
+        v = {}
+        setattr(namespace, self.dest, v)
+
+      if v.get(project_id):
+        raise ValueError('An override is already defined for [%s] (%s)' % (
+                         project_id, v[project_id]))
+      path = os.path.abspath(os.path.expanduser(path))
+      if not os.path.isdir(path):
+        raise ValueError('Override path [%s] is not a directory' % (path,))
+      v[project_id] = path
+
+  def package_type(value):
+    if not os.path.isfile(value):
+      raise argparse.ArgumentTypeError(
+        'Given recipes config file %r does not exist.' % (value,))
+    return package_io.PackageFile(value)
+
+  parser.add_argument(
+      '--package',
+      type=package_type,
+      help='Path to recipes.cfg of the recipe package to operate on'
+        ', usually in infra/config/recipes.cfg')
+  parser.add_argument(
+      '--deps-path',
+      type=os.path.abspath,
+      help='Path where recipe engine dependencies will be extracted. Specify '
+           '"-" to use a temporary directory for deps, which will be cleaned '
+           'up on exit.')
+  parser.add_argument(
+      '--verbose', '-v', action='count',
+      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('-O', '--project-override', metavar='ID=PATH',
+      action=ProjectOverrideAction,
+      help='Override a project repository path with a local one.')
+  parser.add_argument(
+      # Use 'None' as default so that we can recognize when none of the
+      # bootstrap options were passed.
+      '--use-bootstrap', action='store_true', default=None,
+      help='Use bootstrap/bootstrap.py to create a isolated python virtualenv'
+           ' with required python dependencies.')
+  parser.add_argument(
+      '--bootstrap-vpython-path', metavar='PATH',
+      help='Specify the `vpython` executable path to use when bootstrapping ('
+           'requires --use-bootstrap).')
+  parser.add_argument(
+      '--disable-bootstrap', action='store_false', dest='use_bootstrap',
+      help='Disables bootstrap (see --use-bootstrap)')
+
+  def operational_args_type(value):
+    with open(value) as fd:
+      return jsonpb.ParseDict(json.load(fd), arguments_pb2.Arguments())
+
+  parser.set_defaults(
+    operational_args=arguments_pb2.Arguments(),
+    bare_command=False,  # don't call postprocess_func, don't use package_deps
+    postprocess_func=lambda parser, args: None,
+  )
+
+  parser.add_argument(
+      '--operational-args-path',
+      dest='operational_args',
+      type=operational_args_type,
+      help='The path to an operational Arguments file. If provided, this file '
+           'must contain a JSONPB-encoded Arguments protobuf message, and will '
+           'be integrated into the runtime parameters.')
+
+  def post_process_args(parser, args):
+    # TODO(iannucci): We should always do logging.basicConfig() (probably with
+    # logging.WARNING), even if no verbose is passed. However we need to be
+    # careful as this could cause issues with spurious/unexpected output.
+    # I think it's risky enough to do in a different CL.
+
+    if args.verbose > 0:
+      logging.basicConfig()
+      logging.getLogger().setLevel(logging.INFO)
+    if args.verbose > 1:
+      logging.getLogger().setLevel(logging.DEBUG)
+
+    if args.bare_command:
+      # TODO(iannucci): this is gross, and only for the remote subcommand;
+      # remote doesn't behave like ANY other commands. A way to solve this will
+      # be to allow --package to take a remote repo and then simply remove the
+      # remote subcommand entirely.
+      if args.package is not None:
+        parser.error('%s forbids --package' % args.command)
+    else:
+      if not args.package:
+        parser.error('%s requires --package' % args.command)
+
+  return post_process_args