Ansible: Up and Running, 2nd Edition

Appendix A. SSH

Because Ansible uses SSH as its transport mechanism, you’ll need to understand some of SSH’s features to take advantage of them with Ansible.

Native SSH

By default, Ansible uses the native SSH client installed on your operating system. Ansible can take advantage of all the typical SSH features, including Kerberos and jump hosts. If you have an ~/.ssh/config file with custom configurations for your SSH setup, Ansible will respect these settings.

SSH Agent

A handy program called ssh-agent simplifies working with SSH private keys.

When ssh-agent is running on your machine, you can add private keys to it by using the ssh-add command:

$ ssh-add /path/to/keyfile.pem

Note

The SSH_AUTH_SOCK environment variable must be set, or the ssh-add command will not be able to communicate with ssh-agent. See “Starting Up ssh-agent”.

You can use the -l or L flag with the ssh_add program to see which keys have been added to your agent, as shown in Example A-1. This example shows that there are two keys in the agent.

Example A-1. Listing the keys in the agent

$ ssh-add -l 2048 SHA256:o7H/I9rRZupXHJ7JnDi10RhSzeAKYiRVrlH9L/JFtfA /Users/lorin/.ssh/id_rsa 2048 SHA256:xLTmHqvHHDIdcrHiHdtoOXxq5sm9DOEVi+/jnObkKKM insecure_private_key $ ssh-add -L ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDWAfog5tz4W9bPVbPDlNC8HWMfhjTgKOhpSZYI+clc e3/pz5viqsHDQIjzSImoVzIOTV0tOIfE8qMkqEYk7igESccCy0zN9VnD6EfYVkEx1C+xqkCtZTEVuQn d+4qyo222EAVkHm6bAhgyoA9nt9Um9WFO0045yHZL2Do9Z7KXTS4xOqeGF5vv7SiuKcsLjORPcWcYqC fYdrdUdRD9dFq7zFKmpCPJqNwDQDrXbgaTOe+H6cu2f4RrJLp88WY8voB3zJ7avv68eOgah82dovSgw ...