Allow to disable SSL validation in gabbi tests

Gabbi does not allow to pass custom path to (self-signed) SSL certs,
so we can't really re-use the CONF.identity option (as does the AODH
test client).

This patch adds a new config option

  CONF.telemetry.disable_ssl_certificate_validation

(False by default) that will disable SSL cert validation when running
gabbits.

For comparison, see similar patch to heat's tempest plugin
https://review.opendev.org/#/c/703335

Change-Id: I298c8ebb45f0768b12919cf4f67462df0ff4c631

telemetry_tempest_plugin/config.py

@@ -70,6 +70,10 @@ TelemetryGroup = [
     cfg.IntOpt('alarm_threshold',
                default=10,
                help="Threshold to cross for the alarm to trigger."),
+    cfg.BoolOpt("disable_ssl_certificate_validation",
+                default=False,
+                help="Disable SSL certificate validation when running "
+                     "scenario tests"),
 ]
 
 event_opts = [

telemetry_tempest_plugin/scenario/utils.py

@@ -16,13 +16,20 @@ import unittest
 from gabbi import runner
 from gabbi import suitemaker
 from gabbi import utils
+from oslo_config import cfg
 from oslo_log import log as logging
 
 LOG = logging.getLogger(__name__)
+CONF = cfg.CONF
 
 
 def run_test(test_class_instance, test_dir, filename):
     d = utils.load_yaml(yaml_file=os.path.join(test_dir, filename))
+    cert_validate = not CONF.telemetry.disable_ssl_certificate_validation
+    if 'defaults' in d:
+        d['defaults']['cert_validate'] = cert_validate
+    else:
+        d['defaults'] = {'cert_validate': cert_validate}
     test_suite = suitemaker.test_suite_from_dict(
         loader=unittest.defaultTestLoader,
         test_base_name="gabbi",