Digging deeper, it seems like I should be able to say:
type => "%{[@metadata][log_type]}"
or would it be
type =>"%{[log_type]}"
Or if I were trying to use the source field, using:
type => "%{[@metadata][source]}"
Does that look right? Is that how I would access a field within logstash, so that I can appropriately type the data within the input?