AMBARI-21096. ADDENDUM. Provide additional logging for config audit log (alejandro)

ambari-server/src/main/java/org/apache/ambari/server/controller/AmbariManagementControllerImpl.java

@@ -1751,7 +1751,10 @@ public class AmbariManagementControllerImpl implements AmbariManagementControlle
             }
           }
           note = cr.getServiceConfigVersionNote();
-          configs.add(cluster.getConfig(configType, cr.getVersionTag()));
+          Config config = cluster.getConfig(configType, cr.getVersionTag());
+          if (null != config) {
+            configs.add(config);
+          }
         }
         if (!configs.isEmpty()) {
           Map<String, Config> existingConfigTypeToConfig = new HashMap();

ambari-server/src/main/java/org/apache/ambari/server/controller/internal/ConfigGroupResourceProvider.java

@@ -661,10 +661,11 @@ public class ConfigGroupResourceProvider extends
         serviceName = requestServiceName;
       }
 
+      int numHosts = (null != configGroup.getHosts()) ? configGroup.getHosts().size() : 0;
       configLogger.info("(configchange) Updating configuration group host membership or config value. cluster: '{}', changed by: '{}', " +
               "service_name: '{}', config group: '{}', tag: '{}', num hosts in config group: '{}', note: '{}'",
           cluster.getClusterName(), getManagementController().getAuthName(),
-          serviceName, request.getGroupName(), request.getTag(), configGroup.getHosts().size(), request.getServiceConfigVersionNote());
+          serviceName, request.getGroupName(), request.getTag(), numHosts, request.getServiceConfigVersionNote());
 
       if (!request.getConfigs().isEmpty()) {
         List<String> affectedConfigTypeList = new ArrayList(request.getConfigs().keySet());

ambari-server/src/test/java/org/apache/ambari/server/controller/AmbariManagementControllerTest.java

@@ -7417,7 +7417,7 @@ public class AmbariManagementControllerTest {
     Assert.assertEquals(1, responsesWithParams.size());
     StackVersionResponse resp = responsesWithParams.iterator().next();
     assertNotNull(resp.getUpgradePacks());
-    assertEquals(10, resp.getUpgradePacks().size());
+    assertEquals(11, resp.getUpgradePacks().size());
     assertTrue(resp.getUpgradePacks().contains("upgrade_test"));
   }