Audit logging - layout Log4j

Hi @rjan,

Currently, our audit has only one sink available: index. In our backlog, we have a task to add a new type of sink: log. It seems that this is what you want (ref: Remove audit log information from elasticsearch log - #9 by sscarduzio)

I’ll move the task to the top of our current sprint and we will try to implement it as fast as we can.