Remove using of deprecated self.headers (part1)

Attr self.headers in rest client is deprecated now, and
should be removed from usage by service clients.

This patch removes first bunch of attrs.
Second and last part is intended to be in another patch,
with removing from all other service clients
and from rest client itself.

Change-Id: I28981738a9e7f39343cf530c2642315f0a5b22f2
Partially-implements: bp refactor-rest-client
diff --git a/tempest/services/baremetal/base.py b/tempest/services/baremetal/base.py
index 6e86466..5f6b513 100644
--- a/tempest/services/baremetal/base.py
+++ b/tempest/services/baremetal/base.py
@@ -114,7 +114,7 @@
         """
         uri = self._get_uri(resource, permanent=permanent)
 
-        resp, body = self.get(uri, self.headers)
+        resp, body = self.get(uri)
 
         return resp, self.deserialize(body)
 
@@ -127,7 +127,7 @@
 
         """
         uri = self._get_uri(resource, uuid=uuid, permanent=permanent)
-        resp, body = self.get(uri, self.headers)
+        resp, body = self.get(uri)
 
         return resp, self.deserialize(body)
 
@@ -145,7 +145,7 @@
         body = self.serialize(object_type, object_dict)
         uri = self._get_uri(resource)
 
-        resp, body = self.post(uri, headers=self.headers, body=body)
+        resp, body = self.post(uri, body=body)
 
         return resp, self.deserialize(body)
 
@@ -160,7 +160,7 @@
         """
         uri = self._get_uri(resource, uuid)
 
-        resp, body = self.delete(uri, self.headers)
+        resp, body = self.delete(uri)
         return resp, body
 
     def _patch_request(self, resource, uuid, patch_object):
@@ -176,7 +176,7 @@
         uri = self._get_uri(resource, uuid)
         patch_body = json.dumps(patch_object)
 
-        resp, body = self.patch(uri, headers=self.headers, body=patch_body)
+        resp, body = self.patch(uri, body=patch_body)
         return resp, self.deserialize(body)
 
     @handle_errors
diff --git a/tempest/services/identity/v3/json/credentials_client.py b/tempest/services/identity/v3/json/credentials_client.py
index a0fbb76..5d6632a 100644
--- a/tempest/services/identity/v3/json/credentials_client.py
+++ b/tempest/services/identity/v3/json/credentials_client.py
@@ -40,8 +40,7 @@
             "user_id": user_id
         }
         post_body = json.dumps({'credential': post_body})
-        resp, body = self.post('credentials', post_body,
-                               self.headers)
+        resp, body = self.post('credentials', post_body)
         body = json.loads(body)
         body['credential']['blob'] = json.loads(body['credential']['blob'])
         return resp, body['credential']
@@ -63,8 +62,7 @@
             "user_id": user_id
         }
         post_body = json.dumps({'credential': post_body})
-        resp, body = self.patch('credentials/%s' % credential_id, post_body,
-                                self.headers)
+        resp, body = self.patch('credentials/%s' % credential_id, post_body)
         body = json.loads(body)
         body['credential']['blob'] = json.loads(body['credential']['blob'])
         return resp, body['credential']
diff --git a/tempest/services/identity/v3/json/endpoints_client.py b/tempest/services/identity/v3/json/endpoints_client.py
index 1b78115..652c345 100644
--- a/tempest/services/identity/v3/json/endpoints_client.py
+++ b/tempest/services/identity/v3/json/endpoints_client.py
@@ -47,7 +47,7 @@
             'enabled': enabled
         }
         post_body = json.dumps({'endpoint': post_body})
-        resp, body = self.post('endpoints', post_body, self.headers)
+        resp, body = self.post('endpoints', post_body)
         body = json.loads(body)
         return resp, body['endpoint']
 
@@ -66,8 +66,7 @@
         if enabled is not None:
             post_body['enabled'] = enabled
         post_body = json.dumps({'endpoint': post_body})
-        resp, body = self.patch('endpoints/%s' % endpoint_id, post_body,
-                                self.headers)
+        resp, body = self.patch('endpoints/%s' % endpoint_id, post_body)
         body = json.loads(body)
         return resp, body['endpoint']
 
diff --git a/tempest/services/identity/v3/json/identity_client.py b/tempest/services/identity/v3/json/identity_client.py
index ab1dc94..ec3229e 100644
--- a/tempest/services/identity/v3/json/identity_client.py
+++ b/tempest/services/identity/v3/json/identity_client.py
@@ -49,8 +49,7 @@
             'password': password
         }
         post_body = json.dumps({'user': post_body})
-        resp, body = self.post('users', post_body,
-                               self.headers)
+        resp, body = self.post('users', post_body)
         body = json.loads(body)
         return resp, body['user']
 
@@ -72,14 +71,13 @@
             'description': description
         }
         post_body = json.dumps({'user': post_body})
-        resp, body = self.patch('users/%s' % user_id, post_body,
-                                self.headers)
+        resp, body = self.patch('users/%s' % user_id, post_body)
         body = json.loads(body)
         return resp, body['user']
 
     def list_user_projects(self, user_id):
         """Lists the projects on which a user has roles assigned."""
-        resp, body = self.get('users/%s/projects' % user_id, self.headers)
+        resp, body = self.get('users/%s/projects' % user_id)
         body = json.loads(body)
         return resp, body['projects']
 
@@ -112,7 +110,7 @@
             'name': name
         }
         post_body = json.dumps({'project': post_body})
-        resp, body = self.post('projects', post_body, self.headers)
+        resp, body = self.post('projects', post_body)
         body = json.loads(body)
         return resp, body['project']
 
@@ -135,8 +133,7 @@
             'domain_id': domain_id,
         }
         post_body = json.dumps({'project': post_body})
-        resp, body = self.patch('projects/%s' % project_id, post_body,
-                                self.headers)
+        resp, body = self.patch('projects/%s' % project_id, post_body)
         body = json.loads(body)
         return resp, body['project']
 
@@ -157,7 +154,7 @@
             'name': name
         }
         post_body = json.dumps({'role': post_body})
-        resp, body = self.post('roles', post_body, self.headers)
+        resp, body = self.post('roles', post_body)
         body = json.loads(body)
         return resp, body['role']
 
@@ -173,8 +170,7 @@
             'name': name
         }
         post_body = json.dumps({'role': post_body})
-        resp, body = self.patch('roles/%s' % str(role_id), post_body,
-                                self.headers)
+        resp, body = self.patch('roles/%s' % str(role_id), post_body)
         body = json.loads(body)
         return resp, body['role']
 
@@ -186,8 +182,7 @@
     def assign_user_role(self, project_id, user_id, role_id):
         """Add roles to a user on a project."""
         resp, body = self.put('projects/%s/users/%s/roles/%s' %
-                              (project_id, user_id, role_id), None,
-                              self.headers)
+                              (project_id, user_id, role_id), None)
         return resp, body
 
     def create_domain(self, name, **kwargs):
@@ -200,7 +195,7 @@
             'name': name
         }
         post_body = json.dumps({'domain': post_body})
-        resp, body = self.post('domains', post_body, self.headers)
+        resp, body = self.post('domains', post_body)
         body = json.loads(body)
         return resp, body['domain']
 
@@ -227,8 +222,7 @@
             'name': name
         }
         post_body = json.dumps({'domain': post_body})
-        resp, body = self.patch('domains/%s' % domain_id, post_body,
-                                self.headers)
+        resp, body = self.patch('domains/%s' % domain_id, post_body)
         body = json.loads(body)
         return resp, body['domain']
 
@@ -263,13 +257,13 @@
             'name': name
         }
         post_body = json.dumps({'group': post_body})
-        resp, body = self.post('groups', post_body, self.headers)
+        resp, body = self.post('groups', post_body)
         body = json.loads(body)
         return resp, body['group']
 
     def get_group(self, group_id):
         """Get group details."""
-        resp, body = self.get('groups/%s' % group_id, self.headers)
+        resp, body = self.get('groups/%s' % group_id)
         body = json.loads(body)
         return resp, body['group']
 
@@ -283,8 +277,7 @@
             'description': description
         }
         post_body = json.dumps({'group': post_body})
-        resp, body = self.patch('groups/%s' % group_id, post_body,
-                                self.headers)
+        resp, body = self.patch('groups/%s' % group_id, post_body)
         body = json.loads(body)
         return resp, body['group']
 
@@ -296,33 +289,30 @@
     def add_group_user(self, group_id, user_id):
         """Add user into group."""
         resp, body = self.put('groups/%s/users/%s' % (group_id, user_id),
-                              None, self.headers)
+                              None)
         return resp, body
 
     def list_group_users(self, group_id):
         """List users in group."""
-        resp, body = self.get('groups/%s/users' % group_id, self.headers)
+        resp, body = self.get('groups/%s/users' % group_id)
         body = json.loads(body)
         return resp, body['users']
 
     def delete_group_user(self, group_id, user_id):
         """Delete user in group."""
-        resp, body = self.delete('groups/%s/users/%s' % (group_id, user_id),
-                                 self.headers)
+        resp, body = self.delete('groups/%s/users/%s' % (group_id, user_id))
         return resp, body
 
     def assign_user_role_on_project(self, project_id, user_id, role_id):
         """Add roles to a user on a project."""
         resp, body = self.put('projects/%s/users/%s/roles/%s' %
-                              (project_id, user_id, role_id), None,
-                              self.headers)
+                              (project_id, user_id, role_id), None)
         return resp, body
 
     def assign_user_role_on_domain(self, domain_id, user_id, role_id):
         """Add roles to a user on a domain."""
         resp, body = self.put('domains/%s/users/%s/roles/%s' %
-                              (domain_id, user_id, role_id), None,
-                              self.headers)
+                              (domain_id, user_id, role_id), None)
         return resp, body
 
     def list_user_roles_on_project(self, project_id, user_id):
@@ -354,15 +344,13 @@
     def assign_group_role_on_project(self, project_id, group_id, role_id):
         """Add roles to a user on a project."""
         resp, body = self.put('projects/%s/groups/%s/roles/%s' %
-                              (project_id, group_id, role_id), None,
-                              self.headers)
+                              (project_id, group_id, role_id), None)
         return resp, body
 
     def assign_group_role_on_domain(self, domain_id, group_id, role_id):
         """Add roles to a user on a domain."""
         resp, body = self.put('domains/%s/groups/%s/roles/%s' %
-                              (domain_id, group_id, role_id), None,
-                              self.headers)
+                              (domain_id, group_id, role_id), None)
         return resp, body
 
     def list_group_roles_on_project(self, project_id, group_id):
@@ -404,7 +392,7 @@
             'expires_at': expires_at
         }
         post_body = json.dumps({'trust': post_body})
-        resp, body = self.post('OS-TRUST/trusts', post_body, self.headers)
+        resp, body = self.post('OS-TRUST/trusts', post_body)
         body = json.loads(body)
         return resp, body['trust']
 
@@ -507,11 +495,16 @@
             creds['auth']['scope'] = scope
 
         body = json.dumps(creds)
-        resp, body = self.post(self.auth_url, headers=self.headers, body=body)
+        resp, body = self.post(self.auth_url, body=body)
         return resp, body
 
     def request(self, method, url, headers=None, body=None):
         """A simple HTTP request interface."""
+        if headers is None:
+            # Always accept 'json', for xml token client too.
+            # Because XML response is not easily
+            # converted to the corresponding JSON one
+            headers = self.get_headers(accept_type="json")
         self._log_request(method, url, headers, body)
         resp, resp_body = self.http_obj.request(url, method,
                                                 headers=headers, body=body)
diff --git a/tempest/services/identity/v3/json/policy_client.py b/tempest/services/identity/v3/json/policy_client.py
index c376979..5a3f891 100644
--- a/tempest/services/identity/v3/json/policy_client.py
+++ b/tempest/services/identity/v3/json/policy_client.py
@@ -36,7 +36,7 @@
             "type": type
         }
         post_body = json.dumps({'policy': post_body})
-        resp, body = self.post('policies', post_body, self.headers)
+        resp, body = self.post('policies', post_body)
         body = json.loads(body)
         return resp, body['policy']
 
@@ -62,8 +62,7 @@
         }
         post_body = json.dumps({'policy': post_body})
         url = 'policies/%s' % policy_id
-        resp, body = self.patch(url, post_body,
-                                self.headers)
+        resp, body = self.patch(url, post_body)
         body = json.loads(body)
         return resp, body['policy']
 
diff --git a/tempest/services/identity/v3/json/service_client.py b/tempest/services/identity/v3/json/service_client.py
index 92f7629..094e567 100644
--- a/tempest/services/identity/v3/json/service_client.py
+++ b/tempest/services/identity/v3/json/service_client.py
@@ -41,8 +41,7 @@
             'name': name
         }
         patch_body = json.dumps({'service': patch_body})
-        resp, body = self.patch('services/%s' % service_id,
-                                patch_body, self.headers)
+        resp, body = self.patch('services/%s' % service_id, patch_body)
         body = json.loads(body)
         return resp, body['service']
 
diff --git a/tempest/services/identity/v3/xml/credentials_client.py b/tempest/services/identity/v3/xml/credentials_client.py
index eca86ab..f6fa678 100644
--- a/tempest/services/identity/v3/xml/credentials_client.py
+++ b/tempest/services/identity/v3/xml/credentials_client.py
@@ -61,8 +61,7 @@
         credential = Element('credential', project_id=project_id,
                              type=cred_type, user_id=user_id)
         credential.append(blob)
-        resp, body = self.post('credentials', str(Document(credential)),
-                               self.headers)
+        resp, body = self.post('credentials', str(Document(credential)))
         body = self._parse_body(etree.fromstring(body))
         body['blob'] = json.loads(body['blob'])
         return resp, body
@@ -85,27 +84,25 @@
                              type=cred_type, user_id=user_id)
         credential.append(blob)
         resp, body = self.patch('credentials/%s' % credential_id,
-                                str(Document(credential)),
-                                self.headers)
+                                str(Document(credential)))
         body = self._parse_body(etree.fromstring(body))
         body['blob'] = json.loads(body['blob'])
         return resp, body
 
     def get_credential(self, credential_id):
         """To GET Details of a credential."""
-        resp, body = self.get('credentials/%s' % credential_id, self.headers)
+        resp, body = self.get('credentials/%s' % credential_id)
         body = self._parse_body(etree.fromstring(body))
         body['blob'] = json.loads(body['blob'])
         return resp, body
 
     def list_credentials(self):
         """Lists out all the available credentials."""
-        resp, body = self.get('credentials', self.headers)
+        resp, body = self.get('credentials')
         body = self._parse_creds(etree.fromstring(body))
         return resp, body
 
     def delete_credential(self, credential_id):
         """Deletes a credential."""
-        resp, body = self.delete('credentials/%s' % credential_id,
-                                 self.headers)
+        resp, body = self.delete('credentials/%s' % credential_id)
         return resp, body
diff --git a/tempest/services/identity/v3/xml/endpoints_client.py b/tempest/services/identity/v3/xml/endpoints_client.py
index a20a9f5..2a88c15 100644
--- a/tempest/services/identity/v3/xml/endpoints_client.py
+++ b/tempest/services/identity/v3/xml/endpoints_client.py
@@ -58,7 +58,7 @@
 
     def list_endpoints(self):
         """Get the list of endpoints."""
-        resp, body = self.get("endpoints", self.headers)
+        resp, body = self.get("endpoints")
         body = self._parse_array(etree.fromstring(body))
         return resp, body
 
@@ -72,8 +72,7 @@
                                   interface=interface,
                                   url=url, region=region,
                                   enabled=enabled)
-        resp, body = self.post('endpoints', str(Document(create_endpoint)),
-                               self.headers)
+        resp, body = self.post('endpoints', str(Document(create_endpoint)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
@@ -94,8 +93,7 @@
             endpoint.add_attr("region", region)
         if enabled is not None:
             endpoint.add_attr("enabled", enabled)
-        resp, body = self.patch('endpoints/%s' % str(endpoint_id),
-                                str(doc), self.headers)
+        resp, body = self.patch('endpoints/%s' % str(endpoint_id), str(doc))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
diff --git a/tempest/services/identity/v3/xml/identity_client.py b/tempest/services/identity/v3/xml/identity_client.py
index e7b85c1..6304628 100644
--- a/tempest/services/identity/v3/xml/identity_client.py
+++ b/tempest/services/identity/v3/xml/identity_client.py
@@ -98,8 +98,7 @@
                             enabled=str(en).lower(),
                             project_id=project_id,
                             domain_id=domain_id)
-        resp, body = self.post('users', str(Document(post_body)),
-                               self.headers)
+        resp, body = self.post('users', str(Document(post_body)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
@@ -120,32 +119,31 @@
                               description=description,
                               enabled=str(en).lower())
         resp, body = self.patch('users/%s' % user_id,
-                                str(Document(update_user)),
-                                self.headers)
+                                str(Document(update_user)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def list_user_projects(self, user_id):
         """Lists the projects on which a user has roles assigned."""
-        resp, body = self.get('users/%s/projects' % user_id, self.headers)
+        resp, body = self.get('users/%s/projects' % user_id)
         body = self._parse_projects(etree.fromstring(body))
         return resp, body
 
     def get_users(self):
         """Get the list of users."""
-        resp, body = self.get("users", self.headers)
+        resp, body = self.get("users")
         body = self._parse_array(etree.fromstring(body))
         return resp, body
 
     def get_user(self, user_id):
         """GET a user."""
-        resp, body = self.get("users/%s" % user_id, self.headers)
+        resp, body = self.get("users/%s" % user_id)
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def delete_user(self, user_id):
         """Deletes a User."""
-        resp, body = self.delete("users/%s" % user_id, self.headers)
+        resp, body = self.delete("users/%s" % user_id)
         return resp, body
 
     def create_project(self, name, **kwargs):
@@ -160,14 +158,13 @@
                             enabled=str(en).lower(),
                             name=name)
         resp, body = self.post('projects',
-                               str(Document(post_body)),
-                               self.headers)
+                               str(Document(post_body)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def list_projects(self):
         """Get the list of projects."""
-        resp, body = self.get("projects", self.headers)
+        resp, body = self.get("projects")
         body = self._parse_projects(etree.fromstring(body))
         return resp, body
 
@@ -185,14 +182,13 @@
                             enabled=str(en).lower(),
                             domain_id=domain_id)
         resp, body = self.patch('projects/%s' % project_id,
-                                str(Document(post_body)),
-                                self.headers)
+                                str(Document(post_body)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def get_project(self, project_id):
         """GET a Project."""
-        resp, body = self.get("projects/%s" % project_id, self.headers)
+        resp, body = self.get("projects/%s" % project_id)
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
@@ -206,15 +202,13 @@
         post_body = Element("role",
                             xmlns=XMLNS,
                             name=name)
-        resp, body = self.post('roles',
-                               str(Document(post_body)),
-                               self.headers)
+        resp, body = self.post('roles', str(Document(post_body)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def get_role(self, role_id):
         """GET a Role."""
-        resp, body = self.get('roles/%s' % str(role_id), self.headers)
+        resp, body = self.get('roles/%s' % str(role_id))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
@@ -224,21 +218,19 @@
                             xmlns=XMLNS,
                             name=name)
         resp, body = self.patch('roles/%s' % str(role_id),
-                                str(Document(post_body)),
-                                self.headers)
+                                str(Document(post_body)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def delete_role(self, role_id):
         """Delete a role."""
-        resp, body = self.delete('roles/%s' % str(role_id),
-                                 self.headers)
+        resp, body = self.delete('roles/%s' % str(role_id))
         return resp, body
 
     def assign_user_role(self, project_id, user_id, role_id):
         """Add roles to a user on a tenant."""
         resp, body = self.put('projects/%s/users/%s/roles/%s' %
-                              (project_id, user_id, role_id), '', self.headers)
+                              (project_id, user_id, role_id), '')
         return resp, body
 
     def create_domain(self, name, **kwargs):
@@ -250,20 +242,19 @@
                             name=name,
                             description=description,
                             enabled=str(en).lower())
-        resp, body = self.post('domains', str(Document(post_body)),
-                               self.headers)
+        resp, body = self.post('domains', str(Document(post_body)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def list_domains(self):
         """Get the list of domains."""
-        resp, body = self.get("domains", self.headers)
+        resp, body = self.get("domains")
         body = self._parse_domains(etree.fromstring(body))
         return resp, body
 
     def delete_domain(self, domain_id):
         """Delete a domain."""
-        resp, body = self.delete('domains/%s' % domain_id, self.headers)
+        resp, body = self.delete('domains/%s' % domain_id)
         return resp, body
 
     def update_domain(self, domain_id, **kwargs):
@@ -278,14 +269,13 @@
                             description=description,
                             enabled=str(en).lower())
         resp, body = self.patch('domains/%s' % domain_id,
-                                str(Document(post_body)),
-                                self.headers)
+                                str(Document(post_body)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def get_domain(self, domain_id):
         """Get Domain details."""
-        resp, body = self.get('domains/%s' % domain_id, self.headers)
+        resp, body = self.get('domains/%s' % domain_id)
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
@@ -315,14 +305,13 @@
                             description=description,
                             domain_id=domain_id,
                             project_id=project_id)
-        resp, body = self.post('groups', str(Document(post_body)),
-                               self.headers)
+        resp, body = self.post('groups', str(Document(post_body)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def get_group(self, group_id):
         """Get group details."""
-        resp, body = self.get('groups/%s' % group_id, self.headers)
+        resp, body = self.get('groups/%s' % group_id)
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
@@ -336,112 +325,105 @@
                             name=name,
                             description=description)
         resp, body = self.patch('groups/%s' % group_id,
-                                str(Document(post_body)),
-                                self.headers)
+                                str(Document(post_body)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def delete_group(self, group_id):
         """Delete a group."""
-        resp, body = self.delete('groups/%s' % group_id, self.headers)
+        resp, body = self.delete('groups/%s' % group_id)
         return resp, body
 
     def add_group_user(self, group_id, user_id):
         """Add user into group."""
-        resp, body = self.put('groups/%s/users/%s' % (group_id, user_id),
-                              '', self.headers)
+        resp, body = self.put('groups/%s/users/%s' % (group_id, user_id), '')
         return resp, body
 
     def list_group_users(self, group_id):
         """List users in group."""
-        resp, body = self.get('groups/%s/users' % group_id, self.headers)
+        resp, body = self.get('groups/%s/users' % group_id)
         body = self._parse_group_users(etree.fromstring(body))
         return resp, body
 
     def delete_group_user(self, group_id, user_id):
         """Delete user in group."""
-        resp, body = self.delete('groups/%s/users/%s' % (group_id, user_id),
-                                 self.headers)
+        resp, body = self.delete('groups/%s/users/%s' % (group_id, user_id))
         return resp, body
 
     def assign_user_role_on_project(self, project_id, user_id, role_id):
         """Add roles to a user on a project."""
         resp, body = self.put('projects/%s/users/%s/roles/%s' %
-                              (project_id, user_id, role_id), '',
-                              self.headers)
+                              (project_id, user_id, role_id), '')
         return resp, body
 
     def assign_user_role_on_domain(self, domain_id, user_id, role_id):
         """Add roles to a user on a domain."""
         resp, body = self.put('domains/%s/users/%s/roles/%s' %
-                              (domain_id, user_id, role_id), '',
-                              self.headers)
+                              (domain_id, user_id, role_id), '')
         return resp, body
 
     def list_user_roles_on_project(self, project_id, user_id):
         """list roles of a user on a project."""
         resp, body = self.get('projects/%s/users/%s/roles' %
-                              (project_id, user_id), self.headers)
+                              (project_id, user_id))
         body = self._parse_roles(etree.fromstring(body))
         return resp, body
 
     def list_user_roles_on_domain(self, domain_id, user_id):
         """list roles of a user on a domain."""
         resp, body = self.get('domains/%s/users/%s/roles' %
-                              (domain_id, user_id), self.headers)
+                              (domain_id, user_id))
         body = self._parse_roles(etree.fromstring(body))
         return resp, body
 
     def revoke_role_from_user_on_project(self, project_id, user_id, role_id):
         """Delete role of a user on a project."""
         resp, body = self.delete('projects/%s/users/%s/roles/%s' %
-                                 (project_id, user_id, role_id), self.headers)
+                                 (project_id, user_id, role_id))
         return resp, body
 
     def revoke_role_from_user_on_domain(self, domain_id, user_id, role_id):
         """Delete role of a user on a domain."""
         resp, body = self.delete('domains/%s/users/%s/roles/%s' %
-                                 (domain_id, user_id, role_id), self.headers)
+                                 (domain_id, user_id, role_id))
         return resp, body
 
     def assign_group_role_on_project(self, project_id, group_id, role_id):
         """Add roles to a user on a project."""
         resp, body = self.put('projects/%s/groups/%s/roles/%s' %
-                              (project_id, group_id, role_id), '',
-                              self.headers)
+                              (project_id, group_id, role_id), '')
         return resp, body
 
     def assign_group_role_on_domain(self, domain_id, group_id, role_id):
         """Add roles to a user on a domain."""
         resp, body = self.put('domains/%s/groups/%s/roles/%s' %
-                              (domain_id, group_id, role_id), '',
-                              self.headers)
+                              (domain_id, group_id, role_id), '')
         return resp, body
 
     def list_group_roles_on_project(self, project_id, group_id):
         """list roles of a user on a project."""
         resp, body = self.get('projects/%s/groups/%s/roles' %
-                              (project_id, group_id), self.headers)
+                              (project_id, group_id))
         body = self._parse_roles(etree.fromstring(body))
         return resp, body
 
     def list_group_roles_on_domain(self, domain_id, group_id):
         """list roles of a user on a domain."""
         resp, body = self.get('domains/%s/groups/%s/roles' %
-                              (domain_id, group_id), self.headers)
+                              (domain_id, group_id))
         body = self._parse_roles(etree.fromstring(body))
         return resp, body
 
     def revoke_role_from_group_on_project(self, project_id, group_id, role_id):
         """Delete role of a user on a project."""
         resp, body = self.delete('projects/%s/groups/%s/roles/%s' %
-                                 (project_id, group_id, role_id), self.headers)
+                                 (project_id, group_id, role_id))
         return resp, body
 
     def revoke_role_from_group_on_domain(self, domain_id, group_id, role_id):
         """Delete role of a user on a domain."""
         resp, body = self.delete('domains/%s/groups/%s/roles/%s' %
-                                 (domain_id, group_id, role_id), self.headers)
+                                 (domain_id, group_id, role_id))
         return resp, body
 
 
@@ -501,15 +483,16 @@
             scope.append(project)
             auth.append(scope)
 
-        resp, body = self.post(self.auth_url, headers=self.headers,
-                               body=str(Document(auth)))
+        resp, body = self.post(self.auth_url, body=str(Document(auth)))
         return resp, body
 
     def request(self, method, url, headers=None, body=None):
         """A simple HTTP request interface."""
-        # Send XML, accept JSON. XML response is not easily
-        # converted to the corresponding JSON one
-        headers['Accept'] = 'application/json'
+        if headers is None:
+            # Always accept 'json', for xml token client too.
+            # Because XML response is not easily
+            # converted to the corresponding JSON one
+            headers = self.get_headers(accept_type="json")
         self._log_request(method, url, headers, body)
         resp, resp_body = self.http_obj.request(url, method,
                                                 headers=headers, body=body)
diff --git a/tempest/services/identity/v3/xml/policy_client.py b/tempest/services/identity/v3/xml/policy_client.py
index 429c6a4..a7e63a7 100644
--- a/tempest/services/identity/v3/xml/policy_client.py
+++ b/tempest/services/identity/v3/xml/policy_client.py
@@ -59,21 +59,20 @@
     def create_policy(self, blob, type):
         """Creates a Policy."""
         create_policy = Element("policy", xmlns=XMLNS, blob=blob, type=type)
-        resp, body = self.post('policies', str(Document(create_policy)),
-                               self.headers)
+        resp, body = self.post('policies', str(Document(create_policy)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def list_policies(self):
         """Lists the policies."""
-        resp, body = self.get('policies', self.headers)
+        resp, body = self.get('policies')
         body = self._parse_array(etree.fromstring(body))
         return resp, body
 
     def get_policy(self, policy_id):
         """Lists out the given policy."""
         url = 'policies/%s' % policy_id
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
@@ -83,8 +82,7 @@
         type = kwargs.get('type')
         update_policy = Element("policy", xmlns=XMLNS, type=type)
         url = 'policies/%s' % policy_id
-        resp, body = self.patch(url, str(Document(update_policy)),
-                                self.headers)
+        resp, body = self.patch(url, str(Document(update_policy)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
diff --git a/tempest/services/identity/v3/xml/service_client.py b/tempest/services/identity/v3/xml/service_client.py
index df9b234..f43ed2c 100644
--- a/tempest/services/identity/v3/xml/service_client.py
+++ b/tempest/services/identity/v3/xml/service_client.py
@@ -57,14 +57,13 @@
                                  description=description,
                                  type=type)
         resp, body = self.patch('services/%s' % service_id,
-                                str(Document(update_service)),
-                                self.headers)
+                                str(Document(update_service)))
         body = self._parse_body(etree.fromstring(body))
         return resp, body
 
     def get_service(self, service_id):
         """Get Service."""
         url = 'services/%s' % service_id
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = self._parse_body(etree.fromstring(body))
         return resp, body
diff --git a/tempest/services/identity/xml/identity_client.py b/tempest/services/identity/xml/identity_client.py
index 81846da..50403fb 100644
--- a/tempest/services/identity/xml/identity_client.py
+++ b/tempest/services/identity/xml/identity_client.py
@@ -97,7 +97,7 @@
         """Enables or disables a user."""
         enable_user = xml.Element("user", enabled=str(enabled).lower())
         resp, body = self.put('users/%s/enabled' % user_id,
-                              str(xml.Document(enable_user)), self.headers)
+                              str(xml.Document(enable_user)))
         return resp, self._parse_resp(body)
 
     def create_service(self, name, service_type, **kwargs):
diff --git a/tempest/services/image/v1/json/image_client.py b/tempest/services/image/v1/json/image_client.py
index bc9db38..62c7d2f 100644
--- a/tempest/services/image/v1/json/image_client.py
+++ b/tempest/services/image/v1/json/image_client.py
@@ -241,7 +241,7 @@
         body = None
         if can_share:
             body = json.dumps({'member': {'can_share': True}})
-        resp, __ = self.put(url, body, self.headers)
+        resp, __ = self.put(url, body)
         return resp
 
     def delete_member(self, member_id, image_id):
@@ -252,7 +252,7 @@
     def replace_membership_list(self, image_id, member_list):
         url = 'v1/images/%s/members' % image_id
         body = json.dumps({'membership': member_list})
-        resp, data = self.put(url, body, self.headers)
+        resp, data = self.put(url, body)
         data = json.loads(data)
         return resp, data
 
diff --git a/tempest/services/image/v2/json/image_client.py b/tempest/services/image/v2/json/image_client.py
index b825519..58819d0 100644
--- a/tempest/services/image/v2/json/image_client.py
+++ b/tempest/services/image/v2/json/image_client.py
@@ -86,7 +86,7 @@
         data = json.dumps(params)
         self._validate_schema(data)
 
-        resp, body = self.post('v2/images', data, self.headers)
+        resp, body = self.post('v2/images', data)
         body = json.loads(body)
         return resp, body
 
@@ -132,7 +132,7 @@
 
     def add_image_tag(self, image_id, tag):
         url = 'v2/images/%s/tags/%s' % (image_id, tag)
-        resp, body = self.put(url, body=None, headers=self.headers)
+        resp, body = self.put(url, body=None)
         return resp, body
 
     def delete_image_tag(self, image_id, tag):
@@ -150,7 +150,7 @@
     def add_member(self, image_id, member_id):
         url = 'v2/images/%s/members' % image_id
         data = json.dumps({'member': member_id})
-        resp, body = self.post(url, data, self.headers)
+        resp, body = self.post(url, data)
         body = json.loads(body)
         self.expected_success(200, resp)
         return resp, body
@@ -159,7 +159,7 @@
         """Valid status are: ``pending``, ``accepted``,  ``rejected``."""
         url = 'v2/images/%s/members/%s' % (image_id, member_id)
         data = json.dumps({'status': status})
-        resp, body = self.put(url, data, self.headers)
+        resp, body = self.put(url, data)
         body = json.loads(body)
         self.expected_success(200, resp)
         return resp, body
diff --git a/tempest/services/object_storage/object_client.py b/tempest/services/object_storage/object_client.py
index 79c5719..09e484e 100644
--- a/tempest/services/object_storage/object_client.py
+++ b/tempest/services/object_storage/object_client.py
@@ -32,7 +32,7 @@
     def create_object(self, container, object_name, data, params=None):
         """Create storage object."""
 
-        headers = dict(self.headers)
+        headers = self.get_headers()
         if not data:
             headers['content-length'] = '0'
         url = "%s/%s" % (str(container), str(object_name))
@@ -131,7 +131,7 @@
     def create_object_segments(self, container, object_name, segment, data):
         """Creates object segments."""
         url = "{0}/{1}/{2}".format(container, object_name, segment)
-        resp, body = self.put(url, data, self.headers)
+        resp, body = self.put(url, data)
         return resp, body
 
 
diff --git a/tempest/services/orchestration/json/orchestration_client.py b/tempest/services/orchestration/json/orchestration_client.py
index b70b2e8..113003c 100644
--- a/tempest/services/orchestration/json/orchestration_client.py
+++ b/tempest/services/orchestration/json/orchestration_client.py
@@ -90,7 +90,7 @@
 
         # Password must be provided on stack create so that heat
         # can perform future operations on behalf of the user
-        headers = dict(self.headers)
+        headers = self.get_headers()
         headers['X-Auth-Key'] = self.password
         headers['X-Auth-User'] = self.user
         return headers, body
@@ -106,14 +106,14 @@
         """Suspend a stack."""
         url = 'stacks/%s/actions' % stack_identifier
         body = {'suspend': None}
-        resp, body = self.post(url, json.dumps(body), self.headers)
+        resp, body = self.post(url, json.dumps(body))
         return resp, body
 
     def resume_stack(self, stack_identifier):
         """Resume a stack."""
         url = 'stacks/%s/actions' % stack_identifier
         body = {'resume': None}
-        resp, body = self.post(url, json.dumps(body), self.headers)
+        resp, body = self.post(url, json.dumps(body))
         return resp, body
 
     def list_resources(self, stack_identifier):
@@ -232,7 +232,7 @@
     def _validate_template(self, post_body):
         """Returns the validation request result."""
         post_body = json.dumps(post_body)
-        resp, body = self.post('validate', post_body, self.headers)
+        resp, body = self.post('validate', post_body)
         body = json.loads(body)
         return resp, body
 
diff --git a/tempest/services/telemetry/telemetry_client_base.py b/tempest/services/telemetry/telemetry_client_base.py
index a35a1ab..610f07b 100644
--- a/tempest/services/telemetry/telemetry_client_base.py
+++ b/tempest/services/telemetry/telemetry_client_base.py
@@ -38,7 +38,6 @@
     def __init__(self, auth_provider):
         self.rest_client = self.get_rest_client(auth_provider)
         self.rest_client.service = CONF.telemetry.catalog_type
-        self.headers = self.rest_client.headers
         self.version = '2'
         self.uri_prefix = "v%s" % self.version
 
@@ -69,15 +68,15 @@
 
     def post(self, uri, body):
         body = self.serialize(body)
-        resp, body = self.rest_client.post(uri, body, self.headers)
+        resp, body = self.rest_client.post(uri, body)
         body = self.deserialize(body)
         return resp, body
 
     def put(self, uri, body):
-        return self.rest_client.put(uri, body, self.headers)
+        return self.rest_client.put(uri, body)
 
     def get(self, uri):
-        resp, body = self.rest_client.get(uri, self.headers)
+        resp, body = self.rest_client.get(uri)
         body = self.deserialize(body)
         return resp, body
 
diff --git a/tempest/services/volume/json/admin/volume_types_client.py b/tempest/services/volume/json/admin/volume_types_client.py
index 653532e..0d50524 100644
--- a/tempest/services/volume/json/admin/volume_types_client.py
+++ b/tempest/services/volume/json/admin/volume_types_client.py
@@ -64,7 +64,7 @@
         }
 
         post_body = json.dumps({'volume_type': post_body})
-        resp, body = self.post('types', post_body, self.headers)
+        resp, body = self.post('types', post_body)
         body = json.loads(body)
         return resp, body['volume_type']
 
@@ -98,7 +98,7 @@
         """
         url = "types/%s/extra_specs" % str(vol_type_id)
         post_body = json.dumps({'extra_specs': extra_spec})
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         body = json.loads(body)
         return resp, body['extra_specs']
 
@@ -119,6 +119,6 @@
         url = "types/%s/extra_specs/%s" % (str(vol_type_id),
                                            str(extra_spec_name))
         put_body = json.dumps(extra_spec)
-        resp, body = self.put(url, put_body, self.headers)
+        resp, body = self.put(url, put_body)
         body = json.loads(body)
         return resp, body
diff --git a/tempest/services/volume/json/snapshots_client.py b/tempest/services/volume/json/snapshots_client.py
index 0a79469..ba33c49 100644
--- a/tempest/services/volume/json/snapshots_client.py
+++ b/tempest/services/volume/json/snapshots_client.py
@@ -72,15 +72,14 @@
         post_body = {'volume_id': volume_id}
         post_body.update(kwargs)
         post_body = json.dumps({'snapshot': post_body})
-        resp, body = self.post('snapshots', post_body, self.headers)
+        resp, body = self.post('snapshots', post_body)
         body = json.loads(body)
         return resp, body['snapshot']
 
     def update_snapshot(self, snapshot_id, **kwargs):
         """Updates a snapshot."""
         put_body = json.dumps({'snapshot': kwargs})
-        resp, body = self.put('snapshots/%s' % snapshot_id, put_body,
-                              self.headers)
+        resp, body = self.put('snapshots/%s' % snapshot_id, put_body)
         body = json.loads(body)
         return resp, body['snapshot']
 
@@ -135,8 +134,7 @@
     def reset_snapshot_status(self, snapshot_id, status):
         """Reset the specified snapshot's status."""
         post_body = json.dumps({'os-reset_status': {"status": status}})
-        resp, body = self.post('snapshots/%s/action' % snapshot_id, post_body,
-                               self.headers)
+        resp, body = self.post('snapshots/%s/action' % snapshot_id, post_body)
         return resp, body
 
     def update_snapshot_status(self, snapshot_id, status, progress):
@@ -147,21 +145,21 @@
         }
         post_body = json.dumps({'os-update_snapshot_status': post_body})
         url = 'snapshots/%s/action' % str(snapshot_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def create_snapshot_metadata(self, snapshot_id, metadata):
         """Create metadata for the snapshot."""
         put_body = json.dumps({'metadata': metadata})
         url = "snapshots/%s/metadata" % str(snapshot_id)
-        resp, body = self.post(url, put_body, self.headers)
+        resp, body = self.post(url, put_body)
         body = json.loads(body)
         return resp, body['metadata']
 
     def get_snapshot_metadata(self, snapshot_id):
         """Get metadata of the snapshot."""
         url = "snapshots/%s/metadata" % str(snapshot_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = json.loads(body)
         return resp, body['metadata']
 
@@ -169,7 +167,7 @@
         """Update metadata for the snapshot."""
         put_body = json.dumps({'metadata': metadata})
         url = "snapshots/%s/metadata" % str(snapshot_id)
-        resp, body = self.put(url, put_body, self.headers)
+        resp, body = self.put(url, put_body)
         body = json.loads(body)
         return resp, body['metadata']
 
@@ -177,19 +175,18 @@
         """Update metadata item for the snapshot."""
         put_body = json.dumps({'meta': meta_item})
         url = "snapshots/%s/metadata/%s" % (str(snapshot_id), str(id))
-        resp, body = self.put(url, put_body, self.headers)
+        resp, body = self.put(url, put_body)
         body = json.loads(body)
         return resp, body['meta']
 
     def delete_snapshot_metadata_item(self, snapshot_id, id):
         """Delete metadata item for the snapshot."""
         url = "snapshots/%s/metadata/%s" % (str(snapshot_id), str(id))
-        resp, body = self.delete(url, self.headers)
+        resp, body = self.delete(url)
         return resp, body
 
     def force_delete_snapshot(self, snapshot_id):
         """Force Delete Snapshot."""
         post_body = json.dumps({'os-force_delete': {}})
-        resp, body = self.post('snapshots/%s/action' % snapshot_id, post_body,
-                               self.headers)
+        resp, body = self.post('snapshots/%s/action' % snapshot_id, post_body)
         return resp, body
diff --git a/tempest/services/volume/json/volumes_client.py b/tempest/services/volume/json/volumes_client.py
index 0524212..2183c56 100644
--- a/tempest/services/volume/json/volumes_client.py
+++ b/tempest/services/volume/json/volumes_client.py
@@ -81,15 +81,14 @@
         post_body = {'size': size}
         post_body.update(kwargs)
         post_body = json.dumps({'volume': post_body})
-        resp, body = self.post('volumes', post_body, self.headers)
+        resp, body = self.post('volumes', post_body)
         body = json.loads(body)
         return resp, body['volume']
 
     def update_volume(self, volume_id, **kwargs):
         """Updates the Specified Volume."""
         put_body = json.dumps({'volume': kwargs})
-        resp, body = self.put('volumes/%s' % volume_id, put_body,
-                              self.headers)
+        resp, body = self.put('volumes/%s' % volume_id, put_body)
         body = json.loads(body)
         return resp, body['volume']
 
@@ -105,7 +104,7 @@
         }
         post_body = json.dumps({'os-volume_upload_image': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         body = json.loads(body)
         return resp, body['os-volume_upload_image']
 
@@ -117,7 +116,7 @@
         }
         post_body = json.dumps({'os-attach': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def detach_volume(self, volume_id):
@@ -125,7 +124,7 @@
         post_body = {}
         post_body = json.dumps({'os-detach': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def reserve_volume(self, volume_id):
@@ -133,7 +132,7 @@
         post_body = {}
         post_body = json.dumps({'os-reserve': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def unreserve_volume(self, volume_id):
@@ -141,7 +140,7 @@
         post_body = {}
         post_body = json.dumps({'os-unreserve': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def wait_for_volume_status(self, volume_id, status):
@@ -178,28 +177,25 @@
         }
         post_body = json.dumps({'os-extend': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def reset_volume_status(self, volume_id, status):
         """Reset the Specified Volume's Status."""
         post_body = json.dumps({'os-reset_status': {"status": status}})
-        resp, body = self.post('volumes/%s/action' % volume_id, post_body,
-                               self.headers)
+        resp, body = self.post('volumes/%s/action' % volume_id, post_body)
         return resp, body
 
     def volume_begin_detaching(self, volume_id):
         """Volume Begin Detaching."""
         post_body = json.dumps({'os-begin_detaching': {}})
-        resp, body = self.post('volumes/%s/action' % volume_id, post_body,
-                               self.headers)
+        resp, body = self.post('volumes/%s/action' % volume_id, post_body)
         return resp, body
 
     def volume_roll_detaching(self, volume_id):
         """Volume Roll Detaching."""
         post_body = json.dumps({'os-roll_detaching': {}})
-        resp, body = self.post('volumes/%s/action' % volume_id, post_body,
-                               self.headers)
+        resp, body = self.post('volumes/%s/action' % volume_id, post_body)
         return resp, body
 
     def create_volume_transfer(self, vol_id, display_name=None):
@@ -210,16 +206,14 @@
         if display_name:
             post_body['name'] = display_name
         post_body = json.dumps({'transfer': post_body})
-        resp, body = self.post('os-volume-transfer',
-                               post_body,
-                               self.headers)
+        resp, body = self.post('os-volume-transfer', post_body)
         body = json.loads(body)
         return resp, body['transfer']
 
     def get_volume_transfer(self, transfer_id):
         """Returns the details of a volume transfer."""
         url = "os-volume-transfer/%s" % str(transfer_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = json.loads(body)
         return resp, body['transfer']
 
@@ -243,7 +237,7 @@
         }
         url = 'os-volume-transfer/%s/accept' % transfer_id
         post_body = json.dumps({'accept': post_body})
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         body = json.loads(body)
         return resp, body['transfer']
 
@@ -254,28 +248,27 @@
         }
         post_body = json.dumps({'os-update_readonly_flag': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def force_delete_volume(self, volume_id):
         """Force Delete Volume."""
         post_body = json.dumps({'os-force_delete': {}})
-        resp, body = self.post('volumes/%s/action' % volume_id, post_body,
-                               self.headers)
+        resp, body = self.post('volumes/%s/action' % volume_id, post_body)
         return resp, body
 
     def create_volume_metadata(self, volume_id, metadata):
         """Create metadata for the volume."""
         put_body = json.dumps({'metadata': metadata})
         url = "volumes/%s/metadata" % str(volume_id)
-        resp, body = self.post(url, put_body, self.headers)
+        resp, body = self.post(url, put_body)
         body = json.loads(body)
         return resp, body['metadata']
 
     def get_volume_metadata(self, volume_id):
         """Get metadata of the volume."""
         url = "volumes/%s/metadata" % str(volume_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = json.loads(body)
         return resp, body['metadata']
 
@@ -283,7 +276,7 @@
         """Update metadata for the volume."""
         put_body = json.dumps({'metadata': metadata})
         url = "volumes/%s/metadata" % str(volume_id)
-        resp, body = self.put(url, put_body, self.headers)
+        resp, body = self.put(url, put_body)
         body = json.loads(body)
         return resp, body['metadata']
 
@@ -291,12 +284,12 @@
         """Update metadata item for the volume."""
         put_body = json.dumps({'meta': meta_item})
         url = "volumes/%s/metadata/%s" % (str(volume_id), str(id))
-        resp, body = self.put(url, put_body, self.headers)
+        resp, body = self.put(url, put_body)
         body = json.loads(body)
         return resp, body['meta']
 
     def delete_volume_metadata_item(self, volume_id, id):
         """Delete metadata item for the volume."""
         url = "volumes/%s/metadata/%s" % (str(volume_id), str(id))
-        resp, body = self.delete(url, self.headers)
+        resp, body = self.delete(url)
         return resp, body
diff --git a/tempest/services/volume/v2/json/volumes_client.py b/tempest/services/volume/v2/json/volumes_client.py
index 0524212..2183c56 100644
--- a/tempest/services/volume/v2/json/volumes_client.py
+++ b/tempest/services/volume/v2/json/volumes_client.py
@@ -81,15 +81,14 @@
         post_body = {'size': size}
         post_body.update(kwargs)
         post_body = json.dumps({'volume': post_body})
-        resp, body = self.post('volumes', post_body, self.headers)
+        resp, body = self.post('volumes', post_body)
         body = json.loads(body)
         return resp, body['volume']
 
     def update_volume(self, volume_id, **kwargs):
         """Updates the Specified Volume."""
         put_body = json.dumps({'volume': kwargs})
-        resp, body = self.put('volumes/%s' % volume_id, put_body,
-                              self.headers)
+        resp, body = self.put('volumes/%s' % volume_id, put_body)
         body = json.loads(body)
         return resp, body['volume']
 
@@ -105,7 +104,7 @@
         }
         post_body = json.dumps({'os-volume_upload_image': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         body = json.loads(body)
         return resp, body['os-volume_upload_image']
 
@@ -117,7 +116,7 @@
         }
         post_body = json.dumps({'os-attach': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def detach_volume(self, volume_id):
@@ -125,7 +124,7 @@
         post_body = {}
         post_body = json.dumps({'os-detach': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def reserve_volume(self, volume_id):
@@ -133,7 +132,7 @@
         post_body = {}
         post_body = json.dumps({'os-reserve': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def unreserve_volume(self, volume_id):
@@ -141,7 +140,7 @@
         post_body = {}
         post_body = json.dumps({'os-unreserve': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def wait_for_volume_status(self, volume_id, status):
@@ -178,28 +177,25 @@
         }
         post_body = json.dumps({'os-extend': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def reset_volume_status(self, volume_id, status):
         """Reset the Specified Volume's Status."""
         post_body = json.dumps({'os-reset_status': {"status": status}})
-        resp, body = self.post('volumes/%s/action' % volume_id, post_body,
-                               self.headers)
+        resp, body = self.post('volumes/%s/action' % volume_id, post_body)
         return resp, body
 
     def volume_begin_detaching(self, volume_id):
         """Volume Begin Detaching."""
         post_body = json.dumps({'os-begin_detaching': {}})
-        resp, body = self.post('volumes/%s/action' % volume_id, post_body,
-                               self.headers)
+        resp, body = self.post('volumes/%s/action' % volume_id, post_body)
         return resp, body
 
     def volume_roll_detaching(self, volume_id):
         """Volume Roll Detaching."""
         post_body = json.dumps({'os-roll_detaching': {}})
-        resp, body = self.post('volumes/%s/action' % volume_id, post_body,
-                               self.headers)
+        resp, body = self.post('volumes/%s/action' % volume_id, post_body)
         return resp, body
 
     def create_volume_transfer(self, vol_id, display_name=None):
@@ -210,16 +206,14 @@
         if display_name:
             post_body['name'] = display_name
         post_body = json.dumps({'transfer': post_body})
-        resp, body = self.post('os-volume-transfer',
-                               post_body,
-                               self.headers)
+        resp, body = self.post('os-volume-transfer', post_body)
         body = json.loads(body)
         return resp, body['transfer']
 
     def get_volume_transfer(self, transfer_id):
         """Returns the details of a volume transfer."""
         url = "os-volume-transfer/%s" % str(transfer_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = json.loads(body)
         return resp, body['transfer']
 
@@ -243,7 +237,7 @@
         }
         url = 'os-volume-transfer/%s/accept' % transfer_id
         post_body = json.dumps({'accept': post_body})
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         body = json.loads(body)
         return resp, body['transfer']
 
@@ -254,28 +248,27 @@
         }
         post_body = json.dumps({'os-update_readonly_flag': post_body})
         url = 'volumes/%s/action' % (volume_id)
-        resp, body = self.post(url, post_body, self.headers)
+        resp, body = self.post(url, post_body)
         return resp, body
 
     def force_delete_volume(self, volume_id):
         """Force Delete Volume."""
         post_body = json.dumps({'os-force_delete': {}})
-        resp, body = self.post('volumes/%s/action' % volume_id, post_body,
-                               self.headers)
+        resp, body = self.post('volumes/%s/action' % volume_id, post_body)
         return resp, body
 
     def create_volume_metadata(self, volume_id, metadata):
         """Create metadata for the volume."""
         put_body = json.dumps({'metadata': metadata})
         url = "volumes/%s/metadata" % str(volume_id)
-        resp, body = self.post(url, put_body, self.headers)
+        resp, body = self.post(url, put_body)
         body = json.loads(body)
         return resp, body['metadata']
 
     def get_volume_metadata(self, volume_id):
         """Get metadata of the volume."""
         url = "volumes/%s/metadata" % str(volume_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = json.loads(body)
         return resp, body['metadata']
 
@@ -283,7 +276,7 @@
         """Update metadata for the volume."""
         put_body = json.dumps({'metadata': metadata})
         url = "volumes/%s/metadata" % str(volume_id)
-        resp, body = self.put(url, put_body, self.headers)
+        resp, body = self.put(url, put_body)
         body = json.loads(body)
         return resp, body['metadata']
 
@@ -291,12 +284,12 @@
         """Update metadata item for the volume."""
         put_body = json.dumps({'meta': meta_item})
         url = "volumes/%s/metadata/%s" % (str(volume_id), str(id))
-        resp, body = self.put(url, put_body, self.headers)
+        resp, body = self.put(url, put_body)
         body = json.loads(body)
         return resp, body['meta']
 
     def delete_volume_metadata_item(self, volume_id, id):
         """Delete metadata item for the volume."""
         url = "volumes/%s/metadata/%s" % (str(volume_id), str(id))
-        resp, body = self.delete(url, self.headers)
+        resp, body = self.delete(url)
         return resp, body
diff --git a/tempest/services/volume/v2/xml/volumes_client.py b/tempest/services/volume/v2/xml/volumes_client.py
index deb56fd..2b500ae 100644
--- a/tempest/services/volume/v2/xml/volumes_client.py
+++ b/tempest/services/volume/v2/xml/volumes_client.py
@@ -87,7 +87,7 @@
         if params:
             url += '?%s' % urllib.urlencode(params)
 
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         volumes = []
         if body is not None:
@@ -103,7 +103,7 @@
         if params:
             url += '?%s' % urllib.urlencode(params)
 
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         volumes = []
         if body is not None:
@@ -115,7 +115,7 @@
     def get_volume(self, volume_id):
         """Returns the details of a single volume."""
         url = "volumes/%s" % str(volume_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = self._parse_volume(etree.fromstring(body))
         body = self._check_if_bootable(body)
         return resp, body
@@ -151,8 +151,7 @@
         for key, value in attr_to_add.items():
             volume.add_attr(key, value)
 
-        resp, body = self.post('volumes', str(Document(volume)),
-                               self.headers)
+        resp, body = self.post('volumes', str(Document(volume)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body
 
@@ -161,8 +160,7 @@
         put_body = Element("volume", xmlns=XMLNS_11, **kwargs)
 
         resp, body = self.put('volumes/%s' % volume_id,
-                              str(Document(put_body)),
-                              self.headers)
+                              str(Document(put_body)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body
 
@@ -204,7 +202,7 @@
                             mountpoint=mountpoint
                             )
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -213,7 +211,7 @@
         """Detaches a volume from an instance."""
         post_body = Element("os-detach")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -224,7 +222,7 @@
                             image_name=image_name,
                             disk_format=disk_format)
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         volume = xml_to_json(etree.fromstring(body))
         return resp, volume
 
@@ -233,7 +231,7 @@
         post_body = Element("os-extend",
                             new_size=extend_size)
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -244,7 +242,7 @@
                             status=status
                             )
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -253,7 +251,7 @@
         """Volume Begin Detaching."""
         post_body = Element("os-begin_detaching")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -262,7 +260,7 @@
         """Volume Roll Detaching."""
         post_body = Element("os-roll_detaching")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -271,7 +269,7 @@
         """Reserves a volume."""
         post_body = Element("os-reserve")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -280,7 +278,7 @@
         """Restore a reserved volume ."""
         post_body = Element("os-unreserve")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -292,15 +290,14 @@
         if display_name:
             post_body.add_attr('name', display_name)
         resp, body = self.post('os-volume-transfer',
-                               str(Document(post_body)),
-                               self.headers)
+                               str(Document(post_body)))
         volume = xml_to_json(etree.fromstring(body))
         return resp, volume
 
     def get_volume_transfer(self, transfer_id):
         """Returns the details of a volume transfer."""
         url = "os-volume-transfer/%s" % str(transfer_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         volume = xml_to_json(etree.fromstring(body))
         return resp, volume
 
@@ -310,7 +307,7 @@
         if params:
             url += '?%s' % urllib.urlencode(params)
 
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         volumes = []
         if body is not None:
@@ -334,7 +331,7 @@
         """Accept a volume transfer."""
         post_body = Element("accept", auth_key=transfer_auth_key)
         url = 'os-volume-transfer/%s/accept' % transfer_id
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         volume = xml_to_json(etree.fromstring(body))
         return resp, volume
 
@@ -343,7 +340,7 @@
         post_body = Element("os-update_readonly_flag",
                             readonly=readonly)
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -352,7 +349,7 @@
         """Force Delete Volume."""
         post_body = Element("os-force_delete")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -376,15 +373,14 @@
         """Create metadata for the volume."""
         post_body = self._metadata_body(metadata)
         resp, body = self.post('volumes/%s/metadata' % volume_id,
-                               str(Document(post_body)),
-                               self.headers)
+                               str(Document(post_body)))
         body = self._parse_key_value(etree.fromstring(body))
         return resp, body
 
     def get_volume_metadata(self, volume_id):
         """Get metadata of the volume."""
         url = "volumes/%s/metadata" % str(volume_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = self._parse_key_value(etree.fromstring(body))
         return resp, body
 
@@ -392,7 +388,7 @@
         """Update metadata for the volume."""
         put_body = self._metadata_body(metadata)
         url = "volumes/%s/metadata" % str(volume_id)
-        resp, body = self.put(url, str(Document(put_body)), self.headers)
+        resp, body = self.put(url, str(Document(put_body)))
         body = self._parse_key_value(etree.fromstring(body))
         return resp, body
 
@@ -402,7 +398,7 @@
             put_body = Element('meta', key=k)
             put_body.append(Text(v))
         url = "volumes/%s/metadata/%s" % (str(volume_id), str(id))
-        resp, body = self.put(url, str(Document(put_body)), self.headers)
+        resp, body = self.put(url, str(Document(put_body)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body
 
diff --git a/tempest/services/volume/xml/admin/volume_hosts_client.py b/tempest/services/volume/xml/admin/volume_hosts_client.py
index 7278fd9..59652fa 100644
--- a/tempest/services/volume/xml/admin/volume_hosts_client.py
+++ b/tempest/services/volume/xml/admin/volume_hosts_client.py
@@ -67,6 +67,6 @@
         if params:
             url += '?%s' % urllib.urlencode(params)
 
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = self._parse_array(etree.fromstring(body))
         return resp, body
diff --git a/tempest/services/volume/xml/admin/volume_types_client.py b/tempest/services/volume/xml/admin/volume_types_client.py
index 29ba431..802d27a 100644
--- a/tempest/services/volume/xml/admin/volume_types_client.py
+++ b/tempest/services/volume/xml/admin/volume_types_client.py
@@ -72,7 +72,7 @@
         if params:
             url += '?%s' % urllib.urlencode(params)
 
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         volume_types = []
         if body is not None:
@@ -83,7 +83,7 @@
     def get_volume_type(self, type_id):
         """Returns the details of a single volume_type."""
         url = "types/%s" % str(type_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         return resp, self._parse_volume_type(body)
 
@@ -108,8 +108,7 @@
                 spec.append(Text(value))
                 _extra_specs.append(spec)
 
-        resp, body = self.post('types', str(Document(vol_type)),
-                               self.headers)
+        resp, body = self.post('types', str(Document(vol_type)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body
 
@@ -124,7 +123,7 @@
         if params:
             url += '?%s' % urllib.urlencode(params)
 
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         extra_specs = []
         if body is not None:
@@ -136,7 +135,7 @@
         """Returns the details of a single volume_type extra spec."""
         url = "types/%s/extra_specs/%s" % (str(vol_type_id),
                                            str(extra_spec_name))
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         return resp, self._parse_volume_type_extra_specs(body)
 
@@ -160,8 +159,7 @@
         else:
             extra_specs = None
 
-        resp, body = self.post(url, str(Document(extra_specs)),
-                               self.headers)
+        resp, body = self.post(url, str(Document(extra_specs)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body
 
@@ -190,8 +188,7 @@
                 spec.append(Text(value))
                 extra_specs.append(spec)
 
-        resp, body = self.put(url, str(Document(extra_specs)),
-                              self.headers)
+        resp, body = self.put(url, str(Document(extra_specs)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body
 
diff --git a/tempest/services/volume/xml/extensions_client.py b/tempest/services/volume/xml/extensions_client.py
index 21e1d04..03743a6 100644
--- a/tempest/services/volume/xml/extensions_client.py
+++ b/tempest/services/volume/xml/extensions_client.py
@@ -36,6 +36,6 @@
 
     def list_extensions(self):
         url = 'extensions'
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = self._parse_array(etree.fromstring(body))
         return resp, body
diff --git a/tempest/services/volume/xml/snapshots_client.py b/tempest/services/volume/xml/snapshots_client.py
index 4f066a6..9abe042 100644
--- a/tempest/services/volume/xml/snapshots_client.py
+++ b/tempest/services/volume/xml/snapshots_client.py
@@ -47,7 +47,7 @@
         if params:
             url += '?%s' % urllib.urlencode(params)
 
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         snapshots = []
         for snap in body:
@@ -61,7 +61,7 @@
         if params:
             url += '?%s' % urllib.urlencode(params)
 
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         snapshots = []
         for snap in body:
@@ -71,7 +71,7 @@
     def get_snapshot(self, snapshot_id):
         """Returns the details of a single snapshot."""
         url = "snapshots/%s" % str(snapshot_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         return resp, xml_to_json(body)
 
@@ -86,8 +86,7 @@
         snapshot = Element("snapshot", xmlns=XMLNS_11, volume_id=volume_id)
         for key, value in kwargs.items():
             snapshot.add_attr(key, value)
-        resp, body = self.post('snapshots', str(Document(snapshot)),
-                               self.headers)
+        resp, body = self.post('snapshots', str(Document(snapshot)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body
 
@@ -96,8 +95,7 @@
         put_body = Element("snapshot", xmlns=XMLNS_11, **kwargs)
 
         resp, body = self.put('snapshots/%s' % snapshot_id,
-                              str(Document(put_body)),
-                              self.headers)
+                              str(Document(put_body)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body
 
@@ -155,7 +153,7 @@
                             status=status
                             )
         url = 'snapshots/%s/action' % str(snapshot_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -167,7 +165,7 @@
                             progress=progress
                             )
         url = 'snapshots/%s/action' % str(snapshot_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -191,15 +189,14 @@
         """Create metadata for the snapshot."""
         post_body = self._metadata_body(metadata)
         resp, body = self.post('snapshots/%s/metadata' % snapshot_id,
-                               str(Document(post_body)),
-                               self.headers)
+                               str(Document(post_body)))
         body = self._parse_key_value(etree.fromstring(body))
         return resp, body
 
     def get_snapshot_metadata(self, snapshot_id):
         """Get metadata of the snapshot."""
         url = "snapshots/%s/metadata" % str(snapshot_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = self._parse_key_value(etree.fromstring(body))
         return resp, body
 
@@ -207,7 +204,7 @@
         """Update metadata for the snapshot."""
         put_body = self._metadata_body(metadata)
         url = "snapshots/%s/metadata" % str(snapshot_id)
-        resp, body = self.put(url, str(Document(put_body)), self.headers)
+        resp, body = self.put(url, str(Document(put_body)))
         body = self._parse_key_value(etree.fromstring(body))
         return resp, body
 
@@ -217,7 +214,7 @@
             put_body = Element('meta', key=k)
             put_body.append(Text(v))
         url = "snapshots/%s/metadata/%s" % (str(snapshot_id), str(id))
-        resp, body = self.put(url, str(Document(put_body)), self.headers)
+        resp, body = self.put(url, str(Document(put_body)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body
 
@@ -230,7 +227,7 @@
         """Force Delete Snapshot."""
         post_body = Element("os-force_delete")
         url = 'snapshots/%s/action' % str(snapshot_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
diff --git a/tempest/services/volume/xml/volumes_client.py b/tempest/services/volume/xml/volumes_client.py
index deb56fd..2b500ae 100644
--- a/tempest/services/volume/xml/volumes_client.py
+++ b/tempest/services/volume/xml/volumes_client.py
@@ -87,7 +87,7 @@
         if params:
             url += '?%s' % urllib.urlencode(params)
 
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         volumes = []
         if body is not None:
@@ -103,7 +103,7 @@
         if params:
             url += '?%s' % urllib.urlencode(params)
 
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         volumes = []
         if body is not None:
@@ -115,7 +115,7 @@
     def get_volume(self, volume_id):
         """Returns the details of a single volume."""
         url = "volumes/%s" % str(volume_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = self._parse_volume(etree.fromstring(body))
         body = self._check_if_bootable(body)
         return resp, body
@@ -151,8 +151,7 @@
         for key, value in attr_to_add.items():
             volume.add_attr(key, value)
 
-        resp, body = self.post('volumes', str(Document(volume)),
-                               self.headers)
+        resp, body = self.post('volumes', str(Document(volume)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body
 
@@ -161,8 +160,7 @@
         put_body = Element("volume", xmlns=XMLNS_11, **kwargs)
 
         resp, body = self.put('volumes/%s' % volume_id,
-                              str(Document(put_body)),
-                              self.headers)
+                              str(Document(put_body)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body
 
@@ -204,7 +202,7 @@
                             mountpoint=mountpoint
                             )
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -213,7 +211,7 @@
         """Detaches a volume from an instance."""
         post_body = Element("os-detach")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -224,7 +222,7 @@
                             image_name=image_name,
                             disk_format=disk_format)
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         volume = xml_to_json(etree.fromstring(body))
         return resp, volume
 
@@ -233,7 +231,7 @@
         post_body = Element("os-extend",
                             new_size=extend_size)
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -244,7 +242,7 @@
                             status=status
                             )
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -253,7 +251,7 @@
         """Volume Begin Detaching."""
         post_body = Element("os-begin_detaching")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -262,7 +260,7 @@
         """Volume Roll Detaching."""
         post_body = Element("os-roll_detaching")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -271,7 +269,7 @@
         """Reserves a volume."""
         post_body = Element("os-reserve")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -280,7 +278,7 @@
         """Restore a reserved volume ."""
         post_body = Element("os-unreserve")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -292,15 +290,14 @@
         if display_name:
             post_body.add_attr('name', display_name)
         resp, body = self.post('os-volume-transfer',
-                               str(Document(post_body)),
-                               self.headers)
+                               str(Document(post_body)))
         volume = xml_to_json(etree.fromstring(body))
         return resp, volume
 
     def get_volume_transfer(self, transfer_id):
         """Returns the details of a volume transfer."""
         url = "os-volume-transfer/%s" % str(transfer_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         volume = xml_to_json(etree.fromstring(body))
         return resp, volume
 
@@ -310,7 +307,7 @@
         if params:
             url += '?%s' % urllib.urlencode(params)
 
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = etree.fromstring(body)
         volumes = []
         if body is not None:
@@ -334,7 +331,7 @@
         """Accept a volume transfer."""
         post_body = Element("accept", auth_key=transfer_auth_key)
         url = 'os-volume-transfer/%s/accept' % transfer_id
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         volume = xml_to_json(etree.fromstring(body))
         return resp, volume
 
@@ -343,7 +340,7 @@
         post_body = Element("os-update_readonly_flag",
                             readonly=readonly)
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -352,7 +349,7 @@
         """Force Delete Volume."""
         post_body = Element("os-force_delete")
         url = 'volumes/%s/action' % str(volume_id)
-        resp, body = self.post(url, str(Document(post_body)), self.headers)
+        resp, body = self.post(url, str(Document(post_body)))
         if body:
             body = xml_to_json(etree.fromstring(body))
         return resp, body
@@ -376,15 +373,14 @@
         """Create metadata for the volume."""
         post_body = self._metadata_body(metadata)
         resp, body = self.post('volumes/%s/metadata' % volume_id,
-                               str(Document(post_body)),
-                               self.headers)
+                               str(Document(post_body)))
         body = self._parse_key_value(etree.fromstring(body))
         return resp, body
 
     def get_volume_metadata(self, volume_id):
         """Get metadata of the volume."""
         url = "volumes/%s/metadata" % str(volume_id)
-        resp, body = self.get(url, self.headers)
+        resp, body = self.get(url)
         body = self._parse_key_value(etree.fromstring(body))
         return resp, body
 
@@ -392,7 +388,7 @@
         """Update metadata for the volume."""
         put_body = self._metadata_body(metadata)
         url = "volumes/%s/metadata" % str(volume_id)
-        resp, body = self.put(url, str(Document(put_body)), self.headers)
+        resp, body = self.put(url, str(Document(put_body)))
         body = self._parse_key_value(etree.fromstring(body))
         return resp, body
 
@@ -402,7 +398,7 @@
             put_body = Element('meta', key=k)
             put_body.append(Text(v))
         url = "volumes/%s/metadata/%s" % (str(volume_id), str(id))
-        resp, body = self.put(url, str(Document(put_body)), self.headers)
+        resp, body = self.put(url, str(Document(put_body)))
         body = xml_to_json(etree.fromstring(body))
         return resp, body