History

Christian Decker bd811fbd1a pyln: Add safe fallback results for hooks Hooks do not tolerate failures at all. If we return a JSON-RPC error to a hook call the only thing the main daemon can really do is to crash. This commit adds a mapping of error to a safe fallback result, including a warning to the node operator that this should be addressed in the plugin. The warning is reported as a `BROKEN` message, and should therefore fail any testing done on the plugin. Changelog-Fixed: pyln: Fixed HTLCs hanging indefinitely if the hook function raises an exception. A safe fallback result is now returned instead.		2020-09-10 10:27:24 +09:30
..
pyln/client	pyln: Add safe fallback results for hooks	2020-09-10 10:27:24 +09:30
tests	pyln: Migrate implementation from pylightning to pyln-client	2019-11-12 21:23:55 +01:00
README.md	pyln: Split pylightning into multiple pyln modules	2019-09-30 13:27:37 +02:00
requirements.txt	pyln: Migrate implementation from pylightning to pyln-client	2019-11-12 21:23:55 +01:00
setup.py	pyln: Split pylightning into multiple pyln modules	2019-09-30 13:27:37 +02:00

README.md

pyln-client: A python client library for lightningd

This package implements the Unix socket based JSON-RPC protocol that lightningd exposes to the rest of the world. It can be used to call arbitrary functions on the RPC interface, and serves as a basis for plugins written in python.

Installation

pyln-client is available on pip:

pip install pyln-client

Alternatively you can also install the development version to get access to currently unreleased features by checking out the c-lightning source code and installing into your python3 environment:

git clone https://github.com/ElementsProject/lightning.git
cd lightning/contrib/pyln-client
python3 setup.py develop

This will add links to the library into your environment so changing the checked out source code will also result in the environment picking up these changes. Notice however that unreleased versions may change API without warning, so test thoroughly with the released version.

Examples

Using the JSON-RPC client

"""
Generate invoice on one daemon and pay it on the other
"""
from pyln.client import LightningRpc
import random

# Create two instances of the LightningRpc object using two different c-lightning daemons on your computer
l1 = LightningRpc("/tmp/lightning1/lightning-rpc")
l5 = LightningRpc("/tmp/lightning5/lightning-rpc")

info5 = l5.getinfo()
print(info5)

# Create invoice for test payment
invoice = l5.invoice(100, "lbl{}".format(random.random()), "testpayment")
print(invoice)

# Get route to l1
route = l1.getroute(info5['id'], 100, 1)
print(route)

# Pay invoice
print(l1.sendpay(route['route'], invoice['payment_hash']))

Writing a plugin

Plugins are programs that lightningd can be configured to execute alongside the main daemon. They allow advanced interactions with and customizations to the daemon.

#!/usr/bin/env python3
from pyln.client import Plugin

plugin = Plugin()

@plugin.method("hello")
def hello(plugin, name="world"):
    """This is the documentation string for the hello-function.

    It gets reported as the description when registering the function
    as a method with `lightningd`.

    """
    greeting = plugin.get_option('greeting')
    s = '{} {}'.format(greeting, name)
    plugin.log(s)
    return s


@plugin.init()
def init(options, configuration, plugin):
    plugin.log("Plugin helloworld.py initialized")


@plugin.subscribe("connect")
def on_connect(plugin, id, address):
    plugin.log("Received connect event for peer {}".format(id))


plugin.add_option('greeting', 'Hello', 'The greeting I should use.')
plugin.run()