Re: [PATCH v7 20/21] dts: scapy tg docstring update

[Yoan Picchi <yoan.picchi@foss.arm.com>]

On 11/15/23 13:09, Juraj Linkeš wrote:
> Format according to the Google format and PEP257, with slight
> deviations.
> 
> Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> ---
>   .../testbed_model/traffic_generator/scapy.py  | 91 +++++++++++--------
>   1 file changed, 54 insertions(+), 37 deletions(-)
> 
> diff --git a/dts/framework/testbed_model/traffic_generator/scapy.py b/dts/framework/testbed_model/traffic_generator/scapy.py
> index 51864b6e6b..ed4f879925 100644
> --- a/dts/framework/testbed_model/traffic_generator/scapy.py
> +++ b/dts/framework/testbed_model/traffic_generator/scapy.py
> @@ -2,14 +2,15 @@
>   # Copyright(c) 2022 University of New Hampshire
>   # Copyright(c) 2023 PANTHEON.tech s.r.o.
>   
> -"""Scapy traffic generator.
> +"""The Scapy traffic generator.
>   
> -Traffic generator used for functional testing, implemented using the Scapy library.
> +A traffic generator used for functional testing, implemented with
> +`the Scapy library <https://scapy.readthedocs.io/en/latest/>`_.
>   The traffic generator uses an XML-RPC server to run Scapy on the remote TG node.
>   
> -The XML-RPC server runs in an interactive remote SSH session running Python console,
> -where we start the server. The communication with the server is facilitated with
> -a local server proxy.
> +The traffic generator uses the :mod:`xmlrpc.server` module to run an XML-RPC server
> +in an interactive remote Python SSH session. The communication with the server is facilitated
> +with a local server proxy from the :mod:`xmlrpc.client` module.
>   """
>   
>   import inspect
> @@ -69,20 +70,20 @@ def scapy_send_packets_and_capture(
>       recv_iface: str,
>       duration: float,
>   ) -> list[bytes]:
> -    """RPC function to send and capture packets.
> +    """The RPC function to send and capture packets.
>   
> -    The function is meant to be executed on the remote TG node.
> +    The function is meant to be executed on the remote TG node via the server proxy.
>   
>       Args:
>           xmlrpc_packets: The packets to send. These need to be converted to
> -            xmlrpc.client.Binary before sending to the remote server.
> +            :class:`~xmlrpc.client.Binary` objects before sending to the remote server.

The string is not raw and no \s. As per you explanation a few commits 
earlier this might cause an issue with the tilda ?
Looking around I see it also happen several time here and also in the 
previous commit.

>           send_iface: The logical name of the egress interface.
>           recv_iface: The logical name of the ingress interface.
>           duration: Capture for this amount of time, in seconds.
>   
>       Returns:
>           A list of bytes. Each item in the list represents one packet, which needs
> -            to be converted back upon transfer from the remote node.
> +        to be converted back upon transfer from the remote node.
>       """
>       scapy_packets = [scapy.all.Packet(packet.data) for packet in xmlrpc_packets]
>       sniffer = scapy.all.AsyncSniffer(
> @@ -98,19 +99,15 @@ def scapy_send_packets_and_capture(
>   def scapy_send_packets(
>       xmlrpc_packets: list[xmlrpc.client.Binary], send_iface: str
>   ) -> None:
> -    """RPC function to send packets.
> +    """The RPC function to send packets.
>   
> -    The function is meant to be executed on the remote TG node.
> -    It doesn't return anything, only sends packets.
> +    The function is meant to be executed on the remote TG node via the server proxy.
> +    It only sends `xmlrpc_packets`, without capturing them.
>   
>       Args:
>           xmlrpc_packets: The packets to send. These need to be converted to
> -            xmlrpc.client.Binary before sending to the remote server.
> +            :class:`~xmlrpc.client.Binary` objects before sending to the remote server.
>           send_iface: The logical name of the egress interface.
> -
> -    Returns:
> -        A list of bytes. Each item in the list represents one packet, which needs
> -            to be converted back upon transfer from the remote node.
>       """
>       scapy_packets = [scapy.all.Packet(packet.data) for packet in xmlrpc_packets]
>       scapy.all.sendp(scapy_packets, iface=send_iface, realtime=True, verbose=True)
> @@ -130,11 +127,19 @@ def scapy_send_packets(
>   
>   
>   class QuittableXMLRPCServer(SimpleXMLRPCServer):
> -    """Basic XML-RPC server that may be extended
> -    by functions serializable by the marshal module.
> +    r"""Basic XML-RPC server.

But you have a raw string here, and I don't see the need why.

> +
> +    The server may be augmented by functions serializable by the :mod:`marshal` module.
>       """
>   
>       def __init__(self, *args, **kwargs):
> +        """Extend the XML-RPC server initialization.
> +
> +        Args:
> +            args: The positional arguments that will be passed to the superclass's constructor.
> +            kwargs: The keyword arguments that will be passed to the superclass's constructor.
> +                The `allow_none` argument will be set to :data:`True`.
> +        """
>           kwargs["allow_none"] = True
>           super().__init__(*args, **kwargs)
>           self.register_introspection_functions()
> @@ -142,13 +147,12 @@ def __init__(self, *args, **kwargs):
>           self.register_function(self.add_rpc_function)
>   
>       def quit(self) -> None:
> +        """Quit the server."""
>           self._BaseServer__shutdown_request = True
>           return None
>   
>       def add_rpc_function(self, name: str, function_bytes: xmlrpc.client.Binary) -> None:
> -        """Add a function to the server.
> -
> -        This is meant to be executed remotely.
> +        """Add a function to the server from the local server proxy.
>   
>           Args:
>                 name: The name of the function.
> @@ -159,6 +163,11 @@ def add_rpc_function(self, name: str, function_bytes: xmlrpc.client.Binary) -> N
>           self.register_function(function)
>   
>       def serve_forever(self, poll_interval: float = 0.5) -> None:
> +        """Extend the superclass method with an additional print.
> +
> +        Once executed in the local server proxy, the print gives us a clear string to expect
> +        when starting the server. The print means the function was executed on the XML-RPC server.
> +        """
>           print("XMLRPC OK")
>           super().serve_forever(poll_interval)
>   
> @@ -166,19 +175,12 @@ def serve_forever(self, poll_interval: float = 0.5) -> None:
>   class ScapyTrafficGenerator(CapturingTrafficGenerator):
>       """Provides access to scapy functions via an RPC interface.
>   
> -    The traffic generator first starts an XML-RPC on the remote TG node.
> -    Then it populates the server with functions which use the Scapy library
> -    to send/receive traffic.
> -
> -    Any packets sent to the remote server are first converted to bytes.
> -    They are received as xmlrpc.client.Binary objects on the server side.
> -    When the server sends the packets back, they are also received as
> -    xmlrpc.client.Binary object on the client side, are converted back to Scapy
> -    packets and only then returned from the methods.
> +    The class extends the base with remote execution of scapy functions.
>   
> -    Arguments:
> -        tg_node: The node where the traffic generator resides.
> -        config: The user configuration of the traffic generator.
> +    Any packets sent to the remote server are first converted to bytes. They are received as
> +    :class:`~xmlrpc.client.Binary` objects on the server side. When the server sends the packets
> +    back, they are also received as :class:`~xmlrpc.client.Binary` objects on the client side, are
> +    converted back to :class:`scapy.packet.Packet` objects and only then returned from the methods.
>   
>       Attributes:
>           session: The exclusive interactive remote session created by the Scapy
> @@ -192,6 +194,22 @@ class ScapyTrafficGenerator(CapturingTrafficGenerator):
>       _config: ScapyTrafficGeneratorConfig
>   
>       def __init__(self, tg_node: Node, config: ScapyTrafficGeneratorConfig):
> +        """Extend the constructor with Scapy TG specifics.
> +
> +        The traffic generator first starts an XML-RPC on the remote `tg_node`.
> +        Then it populates the server with functions which use the Scapy library
> +        to send/receive traffic:
> +
> +            * :func:`scapy_send_packets_and_capture`
> +            * :func:`scapy_send_packets`
> +
> +        To enable verbose logging from the xmlrpc client, use the :option:`--verbose`
> +        command line argument or the :envvar:`DTS_VERBOSE` environment variable.
> +
> +        Args:
> +            tg_node: The node where the traffic generator resides.
> +            config: The traffic generator's test run configuration.
> +        """
>           super().__init__(tg_node, config)
>   
>           assert (
> @@ -237,10 +255,8 @@ def _start_xmlrpc_server_in_remote_python(self, listen_port: int) -> None:
>               [line for line in src.splitlines() if not line.isspace() and line != ""]
>           )
>   
> -        spacing = "\n" * 4
> -
>           # execute it in the python terminal
> -        self.session.send_command(spacing + src + spacing)
> +        self.session.send_command(src + "\n")
>           self.session.send_command(
>               f"server = QuittableXMLRPCServer(('0.0.0.0', {listen_port}));"
>               f"server.serve_forever()",
> @@ -274,6 +290,7 @@ def _send_packets_and_capture(
>           return scapy_packets
>   
>       def close(self) -> None:
> +        """Close the traffic generator."""
>           try:
>               self.rpc_server_proxy.quit()
>           except ConnectionRefusedError: