Merge branch 'add/circleci' of github.com:vsoch/repo2docker into add/circleci

docs/source/usage.rst

@@ -20,8 +20,8 @@ repo2docker is called with this command::
 
 where ``<URL-or-path to repo>`` is a URL or path to the source repository.
 
-For example, use the following to build an image of the
-`Python Pytudes notebook <https://github.com/norvig/pytudes>`_::
+For example, use the following to build an image of Peter Norvig's
+`Pytudes <https://github.com/norvig/pytudes/>`_::
 
   jupyter-repo2docker https://github.com/norvig/pytudes
 
@@ -47,7 +47,7 @@ Python 3.6 unless you include the version of Python in your
 Python 2.7, 3.5, and 3.6.  In the case of this repo, a Python version is not
 specified in their configuation files and Python 3.6 is installed.
 
-`Python Pytudes Repository <https://github.com/norvig/pytudes>`_
+`Pytudes <https://github.com/norvig/pytudes>`_
 uses a `requirements.txt file <https://github.com/norvig/pytudes/blob/master/requirements.txt>`_
 to specify its Python environment. ``repo2docker`` uses ``pip`` to install
 dependencies listed in the ``requirement.txt`` in the image. To learn more about

repo2docker/app.py

@@ -217,6 +217,7 @@ class Repo2Docker(Application):
     def get_argparser(self):
         """Get arguments that may be used by repo2docker"""
         argparser = argparse.ArgumentParser()
+
         argparser.add_argument(
             '--config',
             default='repo2docker_config.py',
@@ -342,6 +343,14 @@ class Repo2Docker(Application):
             type=str,
             help=self.traits()['appendix'].help,
         )
+
+        argparser.add_argument(
+            '--version',
+            dest='version',
+            action='store_true',
+            help='Print the repo2docker version and exit.'
+        )
+
         return argparser
 
     def json_excepthook(self, etype, evalue, traceback):
@@ -357,6 +366,13 @@ class Repo2Docker(Application):
         """Init repo2docker configuration before start"""
         if argv is None:
             argv = sys.argv[1:]
+
+        # version must be checked before parse, as repo/cmd are required and
+        # will spit out an error if allowed to be parsed first.
+        if '--version' in argv:
+            print(self.version)
+            sys.exit(0)
+
         args = self.get_argparser().parse_args(argv)
 
         if args.debug:

repo2docker/utils.py

@@ -5,7 +5,7 @@ import shutil
 import subprocess
 import sys
 
-from traitlets import Integer
+from traitlets import Integer, TraitError
 
 
 def execute_cmd(cmd, capture=False, **kwargs):