def get_server_ip(nova_client, server_id, network_suffix):
    """Get the ip associated with the nova instance

    :param nova_client: nova client
    :param server_id: uuid of the nova instance whose ip is required
    :param network_suffix: suffix name of the network
    :return: ip address of the instance
    """
    network_name = "rally_network_" + network_suffix
    server_details = nova_client.servers.get(server_id)
    server_ip = server_details.addresses[network_name][0]["addr"]
    return server_ip