setup.py: compute version from git

setup.py

@@ -38,8 +38,40 @@ class install_lib(_install_lib):
         self.run_command('compile_translations')
         _install_lib.run(self)
 
+def get_version():
+    import glob
+    import re
+    import os
+
+    version = None
+    for d in glob.glob('*'):
+        if not os.path.isdir(d):
+            continue
+        module_file = os.path.join(d, '__init__.py')
+        if not os.path.exists(module_file):
+            continue
+        for v in re.findall("""__version__ *= *['"](.*)['"]""",
+                open(module_file).read()):
+            assert version is None
+            version = v
+        if version:
+            break
+    assert version is not None
+    if os.path.exists('.git'):
+        import subprocess
+        p = subprocess.Popen(['git','describe','--dirty', '--match=v*'],
+                stdout=subprocess.PIPE)
+        result = p.communicate()[0]
+        assert p.returncode == 0, 'git returned non-zero'
+        new_version = result.split()[0][1:]
+        major_minor_release = new_version.split('-')[0]
+        assert  version == major_minor_release, \
+                '__version__ (%s) must match the last git annotated tag (%s)' % (version, major_minor_release)
+        version = new_version.replace('-', '.')
+    return version
+
 setup(name='django-journal',
-        version='1.17.0',
+        version=get_version(),
         license='AGPLv3',
         description='Keep a structured -- i.e. not just log strings -- journal'
                     ' of events in your applications',