AMQP Broker Connection Encrypted Attributes

AMQP Broker Connections do not support XML imports in broker.xml or masked user and password configurations.

Importing a <broker-connections> element results in the following:

ERROR [org.apache.activemq.artemis.core.client] AMQ214019: Invalid configuration: org.xml.sax.SAXParseException; cvc-complex-type.3.2.2: Attribute 'xml:base' is not allowed to appear in element 'broker-connections'.

This is a straightforward fix in the artemis-configuration.xsd schema.

Supporting broker connection configuration masked user and password attributes is required for any non-trivial client deployment. Updating the FileConfigurationParser.java AMQP broker connection configuration handler addresses this need.