Support .zip and .csar extension for CSAR files

Support .csar as well as .zip for input CSAR files.
Add unit tests to verify that both .zip and .csar
extensions are validated and parsed properly.

Change-Id: I9d531ceb0e2e1bd36817692677dcbf2b5d5520a9
Closes-Bug: #1506163

toscaparser/tests/test_prereq.py

@@ -221,3 +221,10 @@ class CSARPrereqTest(TestCase):
         shutil.rmtree(csar.temp_dir)
         self.assertTrue(csar.temp_dir is None or
                         not os.path.exists(csar.temp_dir))
+
+    def test_alternate_csar_extension(self):
+        path = os.path.join(self.base_path, "data/CSAR/csar_elk.csar")
+        csar = CSAR(path)
+        self.assertIsNone(csar.validate())
+        self.assertTrue(csar.temp_dir is None or
+                        not os.path.exists(csar.temp_dir))

toscaparser/tests/test_toscatpl.py

@@ -456,3 +456,10 @@ class ToscaTemplateTest(TestCase):
             ValueError,
             lambda: ToscaTemplate(template_file, None, False))
         self.assertEqual(expected_msg, err.__str__())
+
+    def test_csar_with_alternate_extenstion(self):
+        tosca_tpl = os.path.join(
+            os.path.dirname(os.path.abspath(__file__)),
+            "data/CSAR/csar_elk.csar")
+        tosca = ToscaTemplate(tosca_tpl)
+        self.assertTrue(tosca.topology_template.custom_defs)

toscaparser/tosca_template.py

@@ -170,7 +170,7 @@ class ToscaTemplate(object):
     def _get_path(self, path):
         if path.lower().endswith('.yaml'):
             return path
-        elif path.lower().endswith('.zip'):
+        elif path.lower().endswith(('.zip', '.csar')):
             # a CSAR archive
             csar = CSAR(path, self.a_file)
             csar.validate()