This is somewhat contrary to git's intended purpose as a distributed version control system.
If you truly want to limit clones, checkouts, pulls, etc and copying of your code to a specific EC2 instance, you need to install your version control system on that instance and harden it such that the only way your developers can get the code off of it is to "screen capture" it. This means locking down scp, rsync, ftp, http, email, etc, and their ability to compile their own tools.
As Deer Hunter implied, it's much more effective to treat this as a people problem, typically by focusing on hiring trustworthy developers and asking them to sign legally binding non-disclosure agreements.