We recently moved our git repositories over to Amazon Web Services. We ran into one issue with it which was that now our git requests needed to have a key pair attached. The Internet was not very kind on explaining how to do this very well so I'm documenting it here.
The key pair you'll want to use is the one generated for you by AWS. It is the same one you use when you ssh into your AWS EC2 instances. Take this key pair file, which I will call keypair.pem from now on, and we'll need to move it and configure our git to use it.
cp /path/to/file/keypair.pem ~/.ssh/keypair.pem
Host git Hostname EC2PublicDNS User ubuntu IdentityFile /home/username/.ssh/keypair.pem
git clone git:path/to/projects/PROJECT_NAME.git