Fix tempest.conf generation

[service_available] isn't being generated. This patch fixes it.
It also introduces a switch to disable the ec2api tempest tests via
the [service_available]ec2api parameter.

Closes-Bug: #1613542
Change-Id: I79e2bc26f86b3be6a45a2ee8ea33c50977d44838

base.py

@@ -22,6 +22,7 @@ import traceback
 import botocore.exceptions
 from oslo_log import log
 import six
+from tempest import config as tempest_config
 from tempest.lib import base
 from tempest.lib import exceptions
 import testtools
@@ -30,6 +31,7 @@ from ec2api.tests.functional import botocoreclient
 from ec2api.tests.functional import config as cfg
 
 CONF = cfg.CONF
+CONF_TEMPEST = tempest_config.CONF
 LOG = log.getLogger(__name__)
 
 logging.getLogger('botocore').setLevel(logging.INFO)
@@ -253,6 +255,9 @@ class EC2TestCase(base.BaseTestCase):
     @safe_setup
     def setUpClass(cls):
         super(EC2TestCase, cls).setUpClass()
+        if not CONF_TEMPEST.service_available.ec2api:
+            raise cls.skipException("ec2api is disabled")
+
         cls.client = botocoreclient.get_ec2_client(
             CONF.aws.ec2_url, CONF.aws.aws_region,
             CONF.aws.aws_access, CONF.aws.aws_secret,

config_opts.py

@@ -15,6 +15,15 @@
 
 from oslo_config import cfg
 
+service_available_group = cfg.OptGroup(name="service_available",
+                                       title="Available OpenStack Services")
+
+ServiceAvailableGroup = [
+    cfg.BoolOpt("ec2api",
+                default=True,
+                help="Whether or not ec2-api is expected to be available"),
+]
+
 
 aws_group = cfg.OptGroup(name='aws',
                          title='AWS options')

plugin.py

@@ -30,9 +30,16 @@ class AWSTempestPlugin(plugins.TempestPlugin):
         return full_test_dir, base_path
 
     def register_opts(self, conf):
+        config.register_opt_group(
+            conf, aws_config.service_available_group,
+            aws_config.ServiceAvailableGroup)
+
         if aws_config.aws_group.name not in conf:
             config.register_opt_group(conf, aws_config.aws_group,
                                       aws_config.AWSGroup)
 
     def get_opt_lists(self):
-        return [(aws_config.aws_group.name, aws_config.AWSGroup)]
+        return [
+            ('service_available', aws_config.ServiceAvailableGroup),
+            (aws_config.aws_group.name, aws_config.AWSGroup)
+        ]