@Override
  public String getCredentialStoreEnabled(String serviceName) {
    if (setting == null)
      return null;

    // Look up the service and return the credential_store_enabled value.
    Set<HashMap<String, String>> settingValue = setting.getSettingValue(Setting.SETTING_NAME_SERVICE_SETTINGS);
    for (Map<String, String> setting : settingValue) {
      String name = setting.get(Setting.SETTING_NAME_NAME);
      if (StringUtils.equals(name, serviceName)) {
        if (!StringUtils.isEmpty(setting.get(Setting.SETTING_NAME_CREDENTIAL_STORE_ENABLED))) {
          return setting.get(Setting.SETTING_NAME_CREDENTIAL_STORE_ENABLED);
        }
        break;
      }
    }

    return null;
  }
Get whether the specified service is enabled for credential store use.

<pre>
    {@code
      {
        "service_settings" : [
        { "name" : "RANGER",
          "recovery_enabled" : "true",
          "credential_store_enabled" : "true"
        },
        { "name" : "HIVE",
          "recovery_enabled" : "true",
          "credential_store_enabled" : "false"
        },
        { "name" : "TEZ",
          "recovery_enabled" : "false"
        }
      ]
    }
  }
</pre>

@param serviceName - Service name.

@return null if value is not specified; true or false if specified.
ambari-server/src/main/java/org/apache/ambari/server/topology/BlueprintImpl.java