add git describe version handling

setup.py

@@ -1,5 +1,47 @@
+import os
 import os.path
+import subprocess
+
 from setuptools import setup, find_packages
+from distutils.command.sdist import sdist
+
+
+class eo_sdist(sdist):
+    def run(self):
+        if os.path.exists('VERSION'):
+            os.remove('VERSION')
+        version = get_version()
+        version_file = open('VERSION', 'w')
+        version_file.write(version)
+        version_file.close()
+        sdist.run(self)
+        if os.path.exists('VERSION'):
+            os.remove('VERSION')
+
+def get_version():
+    '''Use the VERSION, if absent generates a version with git describe, if not
+       tag exists, take 0.0- and add the length of the commit log.
+    '''
+    if os.path.exists('VERSION'):
+        with open('VERSION', 'r') as v:
+            return v.read()
+    if os.path.exists('.git'):
+        p = subprocess.Popen(['git','describe','--dirty=.dirty','--match=v*'],
+                stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        result = p.communicate()[0]
+        if p.returncode == 0:
+            result = result.decode('ascii').strip()[1:] # strip spaces/newlines and initial v
+            if '-' in result: # not a tagged version
+                real_number, commit_count, commit_hash = result.split('-', 2)
+                version = '%s.post%s+%s' % (real_number, commit_count, commit_hash)
+            else:
+                version = result
+            return version
+        else:
+            return '0.0.post%s' % len(
+                    subprocess.check_output(
+                            ['git', 'rev-list', 'HEAD']).splitlines())
+    return '0.0'
 
 
 def get_source_files():
@@ -9,7 +51,7 @@ def get_source_files():
 
 setup(
     name='django-ckeditor',
-    version='4.5.1',
+    version=get_version(),
     description='Django admin CKEditor integration.',
     long_description=open('README.rst', 'r').read() + open('AUTHORS.rst', 'r').read() + open('CHANGELOG.rst', 'r').read(),
     author='Shaun Sephton & Piotr Malinski',
@@ -31,4 +73,7 @@ setup(
         "Intended Audience :: Developers",
         "Topic :: Internet :: WWW/HTTP :: Dynamic Content",
     ],
+    cmdclass={
+        'sdist': eo_sdist,
+    },
 )