habot 0.0.1

A small example package

habot

A Python package to run highly available Telegram bots

Usage

Install habot with pip:

pip install -i https://test.pypi.org/simple/ habot

(Habot will move to proper pypi at some later date)

Then import and you have two interesting functions available for you code:

import habot
habot.bot.run_primary_backup_model(updater, instances)
habot.bot.run_bot_only(updater)

Of these the latter will only start_polling() and idle() for an Updater of a Telegram bot made using python-telegram-bot package.

run_primary_backup_model will in addition to the bot run a primary-backup system between the instances. The instance is a list of IPs or host/domain names. The workings of the primary-backup model are described in the section below.

How the primary-backup model works

In the primary-backup model, bot code can be started for multiple instances. Primary is the instance that has become primary with the lowest timestamp.

First every instance starts looking for a primary. In case ans instance can find no primary:

1. The instance becomes primary with its current timestamp
2. The instance starts broadcasting that timestamp for other instances by spawning a HTTP server thread
3. Another thread of the instance keeps looking for potential alternative primary with a lower timestamp
4. A watcher thread checks that the other two threads remain alive.
5. Bot code is started in the main thread.

In case the instance does find a primary, it just keeps periodically looking for a primary in the main thread.

If the primary instance A finds another instance B that has become primary with lower timestamp:

1. A stops all its threads.
2. And restarts the cycle by looking for a primary instance.

Security

The instances communicate between themselves over HTTP