b1aed933e6
We had a couple of instances where a plugin would be killed by `lightningd` because we were returning a result of an exception twice, and it was hard to trace down the logic error in the user plugin that caused that. This patch adds a traceback the first time we return a result/exception, and raise an exception with a stacktrace of the first termination when a second one comes in. This can still terminate the plugin, but the programmer gets a clear indication where the result was set, and can potentially even recover from it. Changelog-Added: pyln: Plugin method and hook requests prevent the plugin developer from accidentally setting the result multiple times, and will raise an exception detailing where the result was first set. |
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| .. | ||
| docs | ||
| pyln/client | ||
| tests | ||
| Makefile | ||
| README.md | ||
| requirements.txt | ||
| setup.py | ||
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()