finsy 0.5.0

Async P4Runtime/gNMI Framework

🐟 Finsy P4Runtime Library

Finsy is a P4Runtime controller library written in Python using asyncio. Finsy includes support for gNMI.

import asyncio
import finsy as fy

async def main():
    async with fy.Switch("sw1", "127.0.0.1:50001") as sw1:
        print(sw1.p4info)

asyncio.run(main())

Multiple Switches

With Finsy, you can write a P4Runtime controller that manages multiple switches.

Each switch is managed by an async ready_handler function. Your ready_handler function can read or update various P4Runtime entities in the switch. It can also create tasks to listen for packets or digests.

async def ready_handler(sw: fy.Switch):
    await sw.delete_all()
    await sw.write(
        [
            # Insert multicast group with ports 1, 2, 3 and CONTROLLER.
            +fy.P4MulticastGroupEntry(1, replicas=[1, 2, 3, 255]),
            # Modify default table entry to flood all unmatched packets.
            ~fy.P4TableEntry(
                "ipv4",
                action=fy.P4TableAction("flood"),
                is_default_action=True,
            ),
        ]
    )

    async for packet in sw.read_packets():
        print(f"{sw.name}: {packet}")

Use the SwitchOptions class to specify each switch's settings, including the p4info/p4blob and ready_handler. Use the Controller class to drive multiple switch connections. Each switch will call back into your ready_handler function after the P4Runtime connection is established.

from pathlib import Path

options = fy.SwitchOptions(
    p4info=Path("hello.p4info.txt"),
    p4blob=Path("hello.json"),
    ready_handler=ready_handler,
)

controller = fy.Controller([
    fy.Switch("sw1", "127.0.0.1:50001", options),
    fy.Switch("sw2", "127.0.0.1:50002", options),
    fy.Switch("sw3", "127.0.0.1:50003", options),
])

asyncio.run(controller.run())

For more examples, see the examples directory.