How to use the enoslib.infra.enos_g5k.remote.exec_command_on_nodes function in enoslib

'Installing python...')

    # Bind volumes of docker in /tmp (free storage location on G5k)
    remote.exec_command_on_nodes(
        nodes,
        ('mkdir -p /tmp/docker/volumes; '
         'mkdir -p /var/lib/docker/volumes'),
        'Creating docker volumes directory in /tmp')
    remote.exec_command_on_nodes(
        nodes,
        ('(mount | grep /tmp/docker/volumes) || '
         'mount --bind /tmp/docker/volumes /var/lib/docker/volumes'),
        'Bind mount')

    # Bind nova local storage in /tmp
    remote.exec_command_on_nodes(
        nodes,
        'mkdir -p /tmp/nova ; mkdir -p /var/lib/nova',
        'Creating nova directory in /tmp')
    remote.exec_command_on_nodes(
        nodes,
        ('(mount | grep /tmp/nova) || '
         'mount --bind /tmp/nova /var/lib/nova'),
        'Bind mount')

# Note(jrbalderrama): do we have to implement hash/equals in Host?
    nodes = set([node.address for node in nodes])

    # Provision nodes so we can run Ansible on it
    remote.exec_command_on_nodes(
        nodes,
        'apt-get update && apt-get -y --force-yes install python',
        'Installing python...')

    # Bind volumes of docker in /tmp (free storage location on G5k)
    remote.exec_command_on_nodes(
        nodes,
        ('mkdir -p /tmp/docker/volumes; '
         'mkdir -p /var/lib/docker/volumes'),
        'Creating docker volumes directory in /tmp')
    remote.exec_command_on_nodes(
        nodes,
        ('(mount | grep /tmp/docker/volumes) || '
         'mount --bind /tmp/docker/volumes /var/lib/docker/volumes'),
        'Bind mount')

    # Bind nova local storage in /tmp
    remote.exec_command_on_nodes(
        nodes,
        'mkdir -p /tmp/nova ; mkdir -p /var/lib/nova',
        'Creating nova directory in /tmp')
    remote.exec_command_on_nodes(
        nodes,
        ('(mount | grep /tmp/nova) || '
         'mount --bind /tmp/nova /var/lib/nova'),
        'Bind mount')

nodes = []
    for value in roles.values():
        nodes.extend(value)

    # remove duplicate hosts
    # Note(jrbalderrama): do we have to implement hash/equals in Host?
    nodes = set([node.address for node in nodes])

    # Provision nodes so we can run Ansible on it
    remote.exec_command_on_nodes(
        nodes,
        'apt-get update && apt-get -y --force-yes install python',
        'Installing python...')

    # Bind volumes of docker in /tmp (free storage location on G5k)
    remote.exec_command_on_nodes(
        nodes,
        ('mkdir -p /tmp/docker/volumes; '
         'mkdir -p /var/lib/docker/volumes'),
        'Creating docker volumes directory in /tmp')
    remote.exec_command_on_nodes(
        nodes,
        ('(mount | grep /tmp/docker/volumes) || '
         'mount --bind /tmp/docker/volumes /var/lib/docker/volumes'),
        'Bind mount')

    # Bind nova local storage in /tmp
    remote.exec_command_on_nodes(
        nodes,
        'mkdir -p /tmp/nova ; mkdir -p /var/lib/nova',
        'Creating nova directory in /tmp')
    remote.exec_command_on_nodes(