Make config parser case sensitivity in rally-openstack

rally verify start will convert config options to lowercase
by using configparser, which cannot set the right config
for oslo.config.

Options in config file should be case sensitive, some projects
like octavia-tempest-plugin can't set some value as expected:
[load_balancer]
RBAC_test_type = owner_or_admin

Use `conf.optionxform = str` to prevent case transformation[1].

[1] https://docs.python.org/3/library/configparser.html

Change-Id: I553c962d40ab73e50c1e3f5b229ab553c17fda55
Closes-Bug: #1881456

CHANGELOG.rst

@@ -16,6 +16,17 @@ Changelog
 .. Release notes for existing releases are MUTABLE! If there is something that
    was missed or can be improved, feel free to change it!
 
+[unreleased]
+------------
+
+Fixed
+~~~~~
+
+* [verification component] Make config parser case sensitivity in
+  TempestContext and TempestConfigfileManager.
+
+  `Launchpad-bug #1881456 <https://launchpad.net/bugs/1881456>`_
+
 [2.0.0] - 2020-05-08
 --------------------
 

rally_openstack/verification/tempest/config.py

@@ -49,6 +49,7 @@ class TempestConfigfileManager(object):
         self.available_services = self.clients.services().values()
 
         self.conf = configparser.ConfigParser(allow_no_value=True)
+        self.conf.optionxform = str
 
     def _get_service_type_by_service_name(self, service_name):
         for s_type, s_name in self.clients.services().items():

rally_openstack/verification/tempest/context.py

@@ -53,6 +53,7 @@ class TempestContext(context.VerifierContext):
         self.available_services = self.clients.services().values()
 
         self.conf = configparser.ConfigParser(allow_no_value=True)
+        self.conf.optionxform = str
         self.conf_path = self.verifier.manager.configfile
 
         self.data_dir = self.verifier.manager.home_dir

tests/functional/utils.py

@@ -111,6 +111,7 @@ class Rally(object):
         if self.config_opts:
             self.config_filename = os.path.join(self.tmp_dir, "conf")
             config = configparser.RawConfigParser()
+            config.optionxform = str
             for section, opts in self.config_opts.items():
                 if section.lower() != "default":
                     config.add_section(section)