Define ssh key per host using ansible_ssh_private_key_file

Originally published at: https://www.cyberciti.biz/faq/define-ssh-key-per-host-using-ansible_ssh_private_key_file/

I set up SSH keys on a Linux or Unix as per my project needs and cloud hosting providers. I also new to Ansible IT automation and DevOps tool. My management node has keys for Linode, AWS/EC2 and Google cloud. How do I set up and tell Ansible to use different ssh keys? How do I configure SSH credentials per cloud hosting service provider?