Handle response is not a json format

Change-Id: I62a6c6d248301576176be5631a4ef4900460082d

vmware_nsxlib/tests/unit/v3/test_client.py

@@ -329,6 +329,10 @@ class NsxV3RESTClientTestCase(nsxlib_testcase.NsxClientTestCase):
                                              500157, [777, 500045])
         self.assertEqual(exc, nsxlib_exc.NsxPendingDelete)
 
+        code = requests.codes.SERVICE_UNAVAILABLE
+        exc = client.http_error_to_exception(code, None)
+        self.assertEqual(exc, nsxlib_exc.ServiceUnavailable)
+
 
 class NsxV3JSONClientTestCase(nsxlib_testcase.NsxClientTestCase):
 

vmware_nsxlib/tests/unit/v3/test_cluster.py

@@ -416,6 +416,24 @@ class ClusteredAPITestCase(nsxlib_testcase.NsxClientTestCase):
         # This exception does not ground endpoint
         self.assertEqual(cluster.ClusterHealth.GREEN, api.health)
 
+    def test_max_retry_attempts_on_none_json_error(self):
+        # handle response not json format
+        def server1_error():
+            return mocks.MockRequestsResponse(
+                codes.SERVICE_UNAVAILABLE,
+                "python-requests/2.27.1 d50561a7-7540-4342-88e3-c235e587a19")
+
+        conf_managers = ['8.9.10.11', '9.10.11.12', '10.11.12.13']
+        max_attempts = 2
+        api = self.mock_nsx_clustered_api(
+            nsx_api_managers=conf_managers,
+            max_attempts=max_attempts,
+            session_response=[server1_error for i in range(0, max_attempts)])
+
+        self.assertRaises(nsxlib_exc.ServiceUnavailable,
+                          api.get, 'api/v1/transport-zones')
+        self.assertEqual(cluster.ClusterHealth.GREEN, api.health)
+
     def test_regenerate_error(self):
 
         def server_error():

vmware_nsxlib/v3/client.py

@@ -13,6 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 #
+import json
 import re
 import time
 from urllib import parse as urlparse
@@ -32,7 +33,17 @@ NULL_CURSOR_PREFIX = '0000'
 
 
 def get_http_error_details(response):
-    msg = response.json() if response.content else ''
+    try:
+        msg = response.json() if response.content else ''
+    except json.decoder.JSONDecodeError as e:
+        LOG.debug("decode response %s error %s", response.content, e)
+        # error_code can't be None else it can't be casted to an exception
+        return {'status_code': response.status_code,
+                'error_code': response.status_code,
+                'related_error_codes': [],
+                'related_status_codes': [],
+                'details': response.content}
+
     error_code = None
     related_error_codes = []
     related_status_codes = []