create a GITSSH wrapper in your ~/bin/gitsshwrapperdeploy

#!/bin/bash
ssh -i /home/charlybr/.ssh/deploy_id_rsa $1 $2

export this wrapper when logging in

In your .bashrc for example:
export GITSSH="/home/charlybr/bin/gitsshwrapperdeploy"

or you can just export this env variable when you need it

git clone && code monkey

You're done!