DRONE

Distributed Reactive Orchestration Nodes Environment

DRONE is a Python framework built on top of Atom that turns reactive object graphs into distributed ones. When a member value changes in one process, it is automatically pushed through a message broker to all subscribers on any machine — triggering their local Atom observers as if the change had happened locally.

Installation

pip install drones

A running Redis instance is required for the default RedisBroker.

Quick start

Publisher (process A)

from atom.api import Atom, Float
from drones import Drone, RedisBroker, drone


@drone
class MarketFeed(Atom):
    price = Float().tag(drone_publish="price")


Drone.bind(pubsub_channel="my-app", broker=RedisBroker("redis://localhost:6379"))

feed = MarketFeed()
feed.price = 185.0  # published to every subscriber on the "my-app" channel

Subscriber (process B)

from atom.api import Atom, Float, Int, observe
from drones import Drone, RedisBroker, drone


@drone
class Portfolio(Atom):
    price = Float().tag(drone_node="price")  # fed remotely
    quantity = Int(10)
    total = Float()

    @observe("price")
    def _refresh(self, change):
        self.total = self.price * self.quantity


Drone.bind(pubsub_channel="my-app", broker=RedisBroker("redis://localhost:6379"))

portfolio = Portfolio()
# portfolio.price is updated whenever MarketFeed.price changes in process A,
# firing _refresh through Atom's native observation.

See the examples/ directory for a runnable publisher/subscriber pair, and SPEC.md for the full design specification.

Core concepts

• @drone — class decorator that instruments an Atom subclass.
• drone_publish="name" — tag a member so its changes are published under name.
• drone_node="name" — tag a member so it receives updates for name.
• drone_scope="instance" — restrict delivery to the instance whose drone_id matches (node name on the wire becomes name.<drone_id>).
• Broker — pluggable transport (DroneBroker ABC); RedisBroker ships by default.
• Serializer — pluggable (DroneSerializer ABC); PickleSerializer is the default.

Development

This project uses pixi for local development.

pixi run test        # run the test suite
pixi run lint        # ruff check
pixi run format      # ruff format
pixi run typecheck   # mypy

Releasing

Versions are derived from git tags via hatch-vcs. To publish a release, push a tag and the GitHub Actions workflow builds and publishes to PyPI using trusted publishing:

git tag v0.1.0
git push origin v0.1.0

License

MIT