Add internal version info (spotify#2760)

* Add __meta__ module to store package data.

* Add --version to luigid, add test.

* Fix test.

* Change version description in RELEASE-PROCESS.rst.

* Remove version parameter from luigid.

* use latest version

RELEASE-PROCESS.rst

@@ -2,7 +2,7 @@ For maintainers of Luigi, who have push access to pypi. Here's how you upload
 Luigi to pypi.
 
 #. Make sure [twine](https://pypi.org/project/twine/) is installed ``pip install twine``.
-#. Update version number in `setup.py`.
+#. Update version number in `luigi/__meta__.py`.
 #. Commit, perhaps simply with a commit message like ``Version x.y.z``.
 #. Push to GitHub at [spotify/luigi](https://github.com/spotify/luigi).
 #. Clean up previous distributions by executing ``rm -rf dist``

luigi/__init__.py

@@ -18,6 +18,8 @@
 Package containing core luigi functionality.
 """
 
+from luigi.__meta__ import __version__
+
 from luigi import task
 from luigi.task import Task, Config, ExternalTask, WrapperTask, namespace, auto_namespace
 
@@ -58,7 +60,8 @@
     'FloatParameter', 'BoolParameter', 'TaskParameter',
     'ListParameter', 'TupleParameter', 'EnumParameter', 'DictParameter',
     'configuration', 'interface', 'local_target', 'run', 'build', 'event', 'Event',
-    'NumericalParameter', 'ChoiceParameter', 'OptionalParameter', 'LuigiStatusCode'
+    'NumericalParameter', 'ChoiceParameter', 'OptionalParameter', 'LuigiStatusCode',
+    '__version__',
 ]
 
 if not configuration.get_config().has_option('core', 'autoload-range'):

luigi/__meta__.py

@@ -0,0 +1,11 @@
+# coding: utf-8
+
+"""
+Workflow mgmgt + task scheduling + dependency resolution.
+"""
+
+__author__ = 'The Luigi Authors'
+__contact__ = 'https://github.com/spotify/luigi'
+__license__ = 'Apache License 2.0'
+__version__ = '2.8.10'
+__status__ = 'Production'

setup.py

@@ -68,14 +68,19 @@ def get_static_files(path):
     install_requires = [x for x in install_requires if not x.startswith('python-daemon')]
     install_requires.append('sphinx>=1.4.4')  # Value mirrored in doc/conf.py
 
+# load meta package infos
+meta = {}
+with open("luigi/__meta__.py", "r") as f:
+    exec(f.read(), meta)
+
 setup(
     name='luigi',
-    version='2.8.10',
-    description='Workflow mgmgt + task scheduling + dependency resolution',
+    version=meta['__version__'],
+    description=meta['__doc__'],
     long_description=long_description,
-    author='The Luigi Authors',
-    url='https://github.com/spotify/luigi',
-    license='Apache License 2.0',
+    author=meta['__author__'],
+    url=meta['__contact__'],
+    license=meta['__license__'],
     packages=[
         'luigi',
         'luigi.configuration',