Add find pod by az_region unit test case

1. What is the problem
Tricircle does not have find pod by az_region test case

2. What is the solution to the problem
Implement related test case

3. What the features need to be implemented to the Tricircle
No new features

Change-Id: I65e7eb5d2018ddc554b225cea712d1e413c10e33

tricircle/db/api.py

@@ -311,7 +311,8 @@ def find_pod_by_az_or_region(context, az_or_region):
     # if the pods list contains more than one pod, then we will raise an
     # exception
     if len(pods) > 1:
-        raise Exception('Multiple pods with the same az_name are found')
+        raise exceptions.InvalidInput(
+            reason='Multiple pods with the same az_name are found')
 
 
 def new_job(context, _type, resource_id):

tricircle/tests/unit/db/test_api.py

@@ -17,6 +17,7 @@ from six.moves import xrange
 import unittest
 
 from tricircle.common import context
+from tricircle.common import exceptions
 
 from tricircle.db import api
 from tricircle.db import core
@@ -29,6 +30,15 @@ class APITest(unittest.TestCase):
         core.ModelBase.metadata.create_all(core.get_engine())
         self.context = context.Context()
 
+    def _create_pod(self, index, test_az_uuid):
+        pod_body = {'pod_id': 'test_pod_uuid_%d' % index,
+                    'region_name': 'test_pod_%d' % index,
+                    'pod_az_name': 'test_pod_az_name_%d' % index,
+                    'dc_name': 'test_dc_name_%d' % index,
+                    'az_name': test_az_uuid,
+                    }
+        api.create_pod(self.context, pod_body)
+
     def test_get_bottom_mappings_by_top_id(self):
         for i in xrange(3):
             pod = {'pod_id': 'test_pod_uuid_%d' % i,
@@ -180,5 +190,32 @@ class APITest(unittest.TestCase):
             self.context, current_pod_id='test_pod_uuid_4')
         self.assertIsNone(next_pod)
 
+    def test_find_pod_by_az_or_region(self):
+        self._create_pod(0, 'test_az_uuid1')
+        self._create_pod(1, 'test_az_uuid1')
+        self._create_pod(2, 'test_az_uuid2')
+
+        az_region = None
+        pod = api.find_pod_by_az_or_region(self.context, az_region)
+        self.assertIsNone(pod)
+
+        az_region = 'test_pod_3'
+        self.assertRaises(exceptions.PodNotFound,
+                          api.find_pod_by_az_or_region,
+                          self.context, az_region)
+
+        az_region = 'test_pod_0'
+        pod = api.find_pod_by_az_or_region(self.context, az_region)
+        self.assertEqual(pod['region_name'], az_region)
+
+        az_region = 'test_az_uuid2'
+        pod = api.find_pod_by_az_or_region(self.context, az_region)
+        self.assertEqual(pod['az_name'], az_region)
+
+        az_region = 'test_az_uuid1'
+        self.assertRaises(exceptions.InvalidInput,
+                          api.find_pod_by_az_or_region,
+                          self.context, az_region)
+
     def tearDown(self):
         core.ModelBase.metadata.drop_all(core.get_engine())