pyNetX 1.0.9

NETCONF client with truly async capabilities

pyNetX

pyNetX is a Python library that facilitates both synchronous and asynchronous client-side scripting and application development around the NETCONF protocol. Developed by Sambhu Nampoothiri G, pyNetX provides a modern, efficient interface for interacting with NETCONF-enabled network devices — with truly asynchronous capabilities using non blocking connections.

Current Versions: Stable: v1.0.9

---

v1.0.9 — 2025-07-03

Highlights

• Cancellation-safe asyncio bridge
  • Added a guard (fut_pending()) in the C++ wrapper so callbacks skip set_result()/set_exception() if the Python asyncio.Future has already been cancelled or finished.
  • Why it matters: eliminates sporadic
    asyncio.exceptions.InvalidStateError: invalid state seen when a running task is cancelled or times out while waiting for an RPC reply.

Internal changes

• Minor code changes in the pybind11 wrapper lambdas.

Bug fixes

• No functional regressions introduced by v1.0.8.

Upgrade notes

• Safe to drop-in. There are no API changes compared with v1.0.8.
• If you previously installed pyNetX from Test PyPI, grab the new wheel with

  pip install pyNetX==1.0.9
  

v1.0.8 — 2025-06-30

Highlights

• Epoll-based Notification Subsystem

  • Re-implemented the internal notification reactor on top of Linux epoll, eliminating the legacy select-based notification loop.
  • Why it matters:
    • Scales linearly with the number of active NETCONF notification streams.
    • Dramatically reduces CPU wake-ups under heavy load (measured ~85 % drop at 500 FDs).
    • Lower latency for bursts of notifications, especially when many devices are idle most of the time.
    • No new threads are created for each notification arrival; a fixed pool started at program launch can handle hundreds of devices per thread.

• Smarter Task-Pool Sharing

  • The global task pool now assigns workers to devices dynamically based on real-time queue depth rather than static round-robin.
  • This allows tasks to be spread across queues more efficiently as per current load, minimizing task queue depth and improving aggregate throughput by up to 40 % in mixed-traffic scenarios.

Internal changes

• Added set_notification_reactor_count() to let applications resize the epoll reactor pool on the fly.
• Reworked set_threadpool_size() so the pool can grow or shrink without restarting clients; existing futures stay intact.

Bug fixes

• Fixed a hard-coded NETCONF base 1.0 header in send_rpc_async(rpc="…"); the call now follows the user mentioned version.

Deprecations

• receive_notification_async() has been removed; migrate to next_notification() before v1.0.8.

---

Upgrade tip: If you scaled your own thread/reactor counts manually, call the new setters after creating all client objects to rebalance existing connections.

Documentation

The full documentation (with detailed API references and more usage examples) is here.

pyNetX Official Documentation

Requirements

• Python: 3.11+
• Build Dependencies: setuptools, wheel, cmake, scikit-build, and pybind11
• System Libraries:
  • libxml2, libxslt (for XML processing)
  • libssh2, tinyxml2, and audit tools (if required, install via your system’s package manager)

Note: On Debian/Ubuntu, you might install the system libraries with:

sudo apt-get install libxml2-dev libxslt1-dev libssh2-dev tinyxml2-dev audit

---

Installation

You can install pyNetX in either of the following ways:

1. From PyPI:

   pip install pyNetX
   

2. From Source:

   git clone https://github.com/jackofsometrades99/pyNetX.git
   cd pyNetX
   python setup.py install
   

Examples

Synchronous Usage

Below is an example of how to retrieve a device’s running configuration synchronously:

from pyNetX import NetconfClient

# Create a NETCONF client instance
client = NetconfClient(
    hostname="192.168.1.1",
    port=830,
    username="admin",
    password="admin",
    connect_timeout=30, # CONNECT TIMEOUT FROM CHANNEL. DEFAULT IS 60 SECONDS
    read_timeout=30 # READ TIMEOUT FROM CHANNEL. DEFAULT IS 60 SECONDS
)

# Establish a connection
status = client.connect_sync()

# Retrieve the running configuration
config = client.get_config_sync(source="running")
print("Running Configuration:")
print(config)

# Disconnect from the device
client.disconnect_sync()

Asynchronous Usage

The asynchronous API methods are provided with an _async suffix and integrate with Python’s asyncio. For example:

import asyncio
from pyNetX import NetconfClient

async def main():
    client = NetconfClient(
        hostname="192.168.1.1",
        port=830,
        username="admin",
        password="admin",
        connect_timeout=30, # CONNECT TIMEOUT FROM CHANNEL. DEFAULT IS 60 SECONDS
        read_timeout=30 # READ TIMEOUT FROM CHANNEL. DEFAULT IS 60 SECONDS
    )
    
    # Asynchronously connect to the device
    await status = client.connect_async()
    
    # Retrieve configuration asynchronously
    config = await client.get_config_async(source="running")
    print("Running Configuration:")
    print(config)
    
    # Asynchronously disconnect from the device
    await client.disconnect_async()

# Run the asynchronous main function
asyncio.run(main())

API Overview

The main class provided by pyNetX is NetconfClient, which offers both synchronous and asynchronous methods for NETCONF operations.

Synchronous Methods

• connect_sync()
  Establishes a NETCONF session with the target device.

• disconnect_sync()
  Closes the NETCONF session.

• send_rpc_sync(rpc)
  Sends a custom RPC command.

• get_sync(filter="")
  Retrieves device information using an optional filter.

• get_config_sync(source="running", filter="")
  Retrieves the device configuration.

• copy_config_sync(target, source)
  Copies configuration from one datastore to another.

• delete_config_sync(target)
  Deletes configuration from the specified target.

• validate_sync(source="running")
  Validates the configuration.

• edit_config_sync(target, config, do_validate=False)
  Edits the device configuration.

• subscribe_sync(stream="NETCONF", filter="")
  Subscribes to NETCONF notifications.

• receive_notification_sync() Fetches a single received notification from the notification channel.

• lock_sync(target="running") and unlock_sync(target="running")
  Lock and unlock a configuration datastore, respectively.

• commit_sync()
  Commits any configuration changes.

• locked_edit_config_sync(target, config, do_validate=False)
  Performs an edit configuration operation while holding a lock.

Asynchronous Methods

For every synchronous method, there is an asynchronous counterpart that returns an asyncio Future:

• connect_async()
• disconnect_async()
• send_rpc_async(rpc="")
• next_notificaiton()
• get_async(filter="")
• get_config_async(source="running", filter="")
• copy_config_async(target, source)
• delete_config_async(target)
• validate_async(source="running")
• edit_config_async(target, config, do_validate=False)
• subscribe_async(stream="NETCONF", filter="")
• lock_async(target="running")
• unlock_async(target="running")
• commit_async()
• locked_edit_config_async(target, config, do_validate=False)

Common Methods.

These methods can be used in both synchronous and asynchronous operations:

• delete_subscription() Unsubscribe from recieving notifications.

• set_threadpool_size(nThreads) Sets the number of threads in the shared task pool. The default is 4 threads. The number of threads in the pool determines how many tasks or operations can run concurrently. Note that for each device, operations (such as get_async, edit_config_async, etc.) are executed sequentially using a lock to avoid channel corruption. This nThreads value controls the total number of concurrent operations across all clients (devices) in the application. To use this, you can simply:

  import pyNetX
  pyNetX.set_threadpool_size(10)
  

• set_notification_reactor_count(nThreads) Reconfigure how many background epoll-reactor threads PyNetX will run to monitor notification sockets.

  By default you should first call init(total_devices) or pass your preferred count here. Each reactor thread will manage roughly FD_count / nThreads file descriptors. Calling this at any time will tear down and rebuild the pool, then rebalance all existing subscriptions evenly across the new set of threads.

  import pyNetX
  # Create 8 epoll‐based reactors to handle your notification streams
  pyNetX.set_notification_reactor_count(8)
  

Exception Handling

pyNetX defines custom exceptions to handle various NETCONF-related errors:

• NetconfConnectionRefusedError
  Raised when a connection attempt is refused.

• NetconfAuthError
  Raised when authentication fails.

• NetconfChannelError
  Raised for channel-related errors.

• NetconfException
  The base exception for NETCONF-related issues.