'ssh to a node in cluster_name that has either an id,
dns name, or alias matching node_id
user keyword specifies an alternate user to login as'

def ssh_to_cluster_node(self, cluster_name, node_id, user='root', command=None, forward_x11=False, forward_agent=False, pseudo_tty=False):

    cluster = self.get_cluster(cluster_name, load_receipt=False, require_keys=False)
    node = cluster.get_node(node_id)
    key_location = self.cfg.get_key(node.key_name).get('key_location')
    cluster.key_location = key_location
    cluster.keyname = node.key_name
    cluster.validator.validate_keypair()
    return node.shell(user=user, forward_x11=forward_x11, forward_agent=forward_agent, pseudo_tty=pseudo_tty, command=command)
