Proposed change

#1205 implements the support for .dockerignore and .containerignore files however this requires for people to explicitly add these files to their project.

The goal of this new option would be for example for BinderHub admins to be able to have a default set of files and/or folders that they want to systematically ignore. For example, the .git folder which might be large and not of interest.

Alternative options

Ensure all projects have a .dockerignore or .containerignore file

Who would use this feature?

Currently I see it it mainly for the BinderHub admins.

How much effort will adding it take?

This should not be a big task as part of the logic is already implemented in #1205 and the option values would basically be appended to the list.

Who can do this work?

I can implement that.