Solves an error in the _create_interfaces function in case of custom relationships defined in TOSCA document.

Change-Id: Id780d8a3ddea6f85bc555644b933c1782d7d98e2
Related-Bug: 1551608

toscaparser/entity_template.py

@@ -283,6 +283,9 @@ class EntityTemplate(object):
         type_interfaces = None
         if isinstance(self.type_definition, RelationshipType):
             if isinstance(self.entity_tpl, dict):
+                if self.INTERFACES in self.entity_tpl:
+                    type_interfaces = self.entity_tpl[self.INTERFACES]
+                else:
                     for rel_def, value in self.entity_tpl.items():
                         if rel_def != 'type':
                             rel_def = self.entity_tpl.get(rel_def)

toscaparser/tests/data/test_tosca_custom_rel_with_script.yaml

@@ -0,0 +1,23 @@
+tosca_definitions_version: tosca_simple_yaml_1_0
+
+description: Test template of a custom relationship with a configure script
+
+topology_template:
+
+  node_templates:
+    apache:
+      type: tosca.nodes.WebServer
+      requirements:
+        - host:
+            node: web_server
+            relationship: my_custom_rel
+
+    web_server:
+      type: tosca.nodes.Compute
+
+  relationship_templates:
+    my_custom_rel:
+      type: HostedOn
+      interfaces:
+        Configure:
+          pre_configure_source: scripts/wp_db_configure.sh

toscaparser/tests/test_toscatpl.py

@@ -716,3 +716,12 @@ class ToscaTemplateTest(TestCase):
             os.path.dirname(os.path.abspath(__file__)),
             "data/test_custom_caps_def.yaml")
         ToscaTemplate(tosca_tpl)
+
+    def test_custom_rel_with_script(self):
+        tosca_tpl = os.path.join(
+            os.path.dirname(os.path.abspath(__file__)),
+            "data/test_tosca_custom_rel_with_script.yaml")
+        tosca = ToscaTemplate(tosca_tpl)
+        rel = tosca.relationship_templates[0]
+        self.assertEqual(len(rel.interfaces), 1)
+        self.assertEqual(rel.interfaces[0].type, "Configure")