Add a node to a pool

    CLI Examples:

    .. code-block:: bash

        salt-run f5.add_pool_member load_balancer 10.0.0.1 80 my_pool

def add_pool_member(lb, name, port, pool_name):
    '''
    Add a node to a pool

    CLI Examples:

    .. code-block:: bash

        salt-run f5.add_pool_member load_balancer 10.0.0.1 80 my_pool
    '''
    if __opts__['load_balancers'].get(lb, None):
        (username, password) = list(__opts__['load_balancers'][lb].values())
    else:
        raise Exception('Unable to find `{0}` load balancer'.format(lb))
    F5 = F5Mgmt(lb, username, password)
    F5.add_pool_member(name, port, pool_name)
    return True