Create a New SSH Key Pair

Open a terminal and run the following command:

ssh-keygen 

SSH config, which is a per-user configuration file for SSH communication. Create a new file: ~/.ssh/config and open it for editing:

nano ~/.ssh/config

Managing Custom Named SSH key

The first thing we are going to solve using this config file is to avoid having to add custom-named SSH keys using ssh-add. Assuming your private SSH key is named ~/.ssh/id_rsa, add following to the config file:

Host github
  HostName github.com
  User git
  IdentityFile ~/.ssh/id_rsa
  IdentitiesOnly yes

Now you can use git clone git@github:username/project