Fabric and ssh-agent, see https://www.leepa.io/2010/11/09/fabric-and-ssh-agent-aka-running-git-in-fabric

fabric_ssh_agent.py

def _shell_escape(string):
    """ Escape double quotes, backticks and
    dollar signs in given ``string``.

    For example:

    >>> _shell_escape('abc$') 'abc\\\\$'
    >>> _shell_escape('"') '\\\\"'
"""
    for char in ('"', '$', '`'):
        string = string.replace(char, '\%s' % char)
    return string

def sshagent_run(cmd, shell=True):
    """ Helper function. Runs a command with SSH agent forwarding enabled.

    Note:: Fabric (and paramiko) can't forward your SSH agent. This helper uses
    your system's ssh to do so. """

    real_command = cmd

    # We have to grab the env['cwd'] and then munge it blank
    # otherwise the call to local() will not run as it'll try and
    # do a local cd - that is not desired.
    cwd = env.get('cwd', '') env['cwd'] = ''

    if shell:
        # Handle cwd munging via 'cd' context manager
        cwd_cmd = ''
        if cwd:
          cwd_cmd = 'cd %s && ' % _shell_escape(cwd)
        # Construct final real, full command
        real_command = '%s \\"%s\\"' % (env.shell, _shell_escape(cwd_cmd + real_command))

    print("[%s] sshagent_run: %s" % (env.host_string, cmd))

    try:
        print local('ssh -p %s -A %s@%s "%s"' % (env.port, env.user, env.host, real_command), capture=False)
    except ValueError, v:
        print v
    finally:
        # Put the cwd back if needed
        env['cwd'] = cwd