Git clone - use different keys for different repositories / user another private key

To clone git repository with a different private key than your /home/user/.ssh/id_rsa

1. Create a script called: git_ssh_wrapper.sh
2. Give the script executable permissions:
   
   chmod 777 git_ssh_wrapper.sh
   
3. The contents of the script should look like the following:
   
   #!/bin/bash
   ssh -i /home/user/RSA_Keys/id_rsa $1 $2
   
4. Export variable GIT_SSH:
   export GIT_SSH=~/git_ssh_wrapper.sh
5. Clone the repository as usual:
   
   git clone user@server.com/repository.git