Boundary nodes source code?

I am preparing a talk about the Internet Computer right now, and am stuck a bit explaining how the boundary nodes actually work internally, so I checked, but unless I am mistaken I cannot find boundary-node related code there.

Is the code (custom software and configuration) for the boundary nodes already public?


Now that the IC code dump is more complete, I believe this is the code for the boundary node:

But the testnet in the path confuses me. Maybe @ianblenke can clarify?