Provide an admin command, to dump the current broker configuration. The ConfigurationImpl Bean.

With properties config, it is important be be able to see the total values in play, also the hard coded defaults.

if we can capture the full config as properties in json, we can use that as it will be more compact. Otherwise use fully qualified properties.

What is the default location, the broker working directory. 

we have <work-dir> etc, data, we could make <work-dir> dump/config.json

Is there a need for config-N.json where N increments? It is simpler if it just overwrites any existing config.json and we don't have to limit N or cleanup.

some of the finer detail will need thought.

Using a well known name in a well known existing location may be sufficient and will pose a minimal risk as the config does not leave the server.