Prevent TypeError in get_active_endpoint function

Sometimes "endpoints_dict" var can be evaluated to None
resulting in "TypeError: 'NoneType' object is not iterable"
error. This patch catches the exception while getting
list of endpoints and checks the value of
endpoints_dict.  Also the amount of active endpoints is being logged
for debug purposes.

Change-Id: I79f6b0b5ced8129b9a28c120b61e3ee050af4336

mariadb/Chart.yaml

@@ -15,7 +15,7 @@ apiVersion: v1
 appVersion: v10.6.7
 description: OpenStack-Helm MariaDB
 name: mariadb
-version: 0.2.57
+version: 0.2.58
 home: https://mariadb.com/kb/en/
 icon: http://badges.mariadb.org/mariadb-badge-180x60.png
 sources:

mariadb/templates/bin/_start.py.tpl

@@ -616,13 +616,17 @@ def get_active_endpoints(endpoints_name=direct_svc_name,
                       (default direct_svc_name)
     namespace -- namespace to check for endpoints (default pod_namespace)
     """
-    endpoints = k8s_api_instance.read_namespaced_endpoints(
-        name=endpoints_name, namespace=pod_namespace)
+    try:
+        endpoints = k8s_api_instance.read_namespaced_endpoints(
+            name=endpoints_name, namespace=pod_namespace)
+    except kubernetes.client.rest.ApiException as error:
+        logger.error("Failed to get mariadb service with error: {0}".format(error))
+        raise error
     endpoints_dict = endpoints.to_dict()
-    addresses_index = [
-        i for i, s in enumerate(endpoints_dict['subsets']) if 'addresses' in s
-    ][0]
-    active_endpoints = endpoints_dict['subsets'][addresses_index]['addresses']
+    active_endpoints = []
+    if endpoints_dict['subsets']:
+        active_endpoints = [s['addresses'] for s in endpoints_dict['subsets'] if 'addresses' in s
+        ][0]
     return active_endpoints
 
 
@@ -638,8 +642,10 @@ def check_for_active_nodes(endpoints_name=direct_svc_name,
     logger.info("Checking for active nodes")
     active_endpoints = get_active_endpoints()
     if active_endpoints and len(active_endpoints) >= 1:
+        logger.info("Amount of active endpoints:  {0}".format(len(active_endpoints)))
         return True
     else:
+        logger.info("Amount of active endpoints:  0")
         return False
 
 

releasenotes/notes/mariadb.yaml

@@ -73,4 +73,5 @@ mariadb:
   - 0.2.55 Improve python3 compatibility
   - 0.2.56 Stop running threads on sigkill
   - 0.2.57 Remove useless retries on conflicts during cm update
+  - 0.2.58 Prevent TypeError in get_active_endpoint function
 ...