django-ethereum-events 0.1.3

Django Ethereum Events

Ethereum Contract Event Log monitoring in Django

Overview

This package provides an easy way to monitor an ethereum blockchain for transactions that invoke Contract Events that are of particular interest.

The main concept was inspired by the following project:

• https://github.com/gnosis/django-eth-events

Installation

1. Either checkout django-ethereum-events from GitHub, or install using pip:

   pip install django-ethereum-events

2. Make sure to include 'django_ethereum_events' in your INSTALLED_APPS

   INSTALLED_APPS += ('django_ethereum_events')

3. Make necessary migrations

   python manage.py migrate django_ethereum_events

Usage

1. In your settings file, specify the following settings

   ETHEREUM_NODE_HOST = 'localhost'
   ETHEREUM_NODE_PORT = 8545
   ETHEREUM_NODE_SSL = False
   ETHEREUM_EVENTS = []

2. ETHEREUM_EVENTS parameter is a list of that holds information about the specific events to monitor for. Its syntax is the following

   ETHEREUM_EVENTS = [
       {
           'CONTRACT_ADDRESS': 'contract address',
           'EVENT_ABI': 'abi of the event(not the whole contract abi)',
           'EVENT_RECEIVER': 'custom event handler'
       }
   ]

3. Create an appropriate EVENT_RECEIVER

   from django_ethereum_events.chainevents import AbstractEventReceiver
   
   class CustomEventReceiver(AbsractEventReceiver):
       def save(self, decoded_event):
           # custom logic goes here

   The decoded_event parameter is the decoded log as provided from web3.utils.events.get_event_data method.

4. To start monitoring the blockchain, either run the celery task django_ethereum_events.tasks.event_listener or better, use celerybeat to run it as a periodical task

   from celery.beat import crontab
   
   CELERYBEAT_SCHEDULE = {
   'ethereum_events': {
       'task': 'django_ethereum_events.tasks.event_listener',
       'schedule': crontab(minute='*/5')  # run every 5 minutes
       }
   }

   You can also set the optional ETHEREUM_LOGS_BATCH_SIZE setting which limits the maximum amount of the blocks that can be read at a time from the celery task.