Notify a discord channel when someone logs into a minecraft server. Run it on the same machine as it needs to be able to read logs files

bot.py

import os
import discord
import asyncio
import event_source

client = discord.Client()

async def activity_messenger_task():
    await client.wait_until_ready()
    print('Client is ready, activity task will begin running...')
    channel = client.get_channel(int(os.environ.get('DISBOARD_CHANNEL_ID', None)))

    for evt in event_source.get_activity_events():
        print(evt)
        if evt['event'] == event_source.EVENT_LOGIN:
            msg = "{player} joined the game".format(player=evt['data']['player'])
        elif evt['event'] == event_source.EVENT_LOGOUT:
            msg = "{player} left the game".format(player=evt['data']['player'])
            if evt['data']['reason'] != "Disconnected":
                msg += "\n@administrator Reason was not Disconnected! [reason={reason}]".format(reason=evt['data']['reason'])
        else:
            continue

        await channel.send(msg)

@client.event
async def on_ready():
    print('We have logged in as {0.user}'.format(client))

@client.event
async def on_message(message):
    if message.author == client.user:
        return

if __name__ == '__main__':
    client.loop.create_task(activity_messenger_task())
    client.run(os.environ.get('DISCORD_BOT_TOKEN', None))

event_source.py

import os
import time
import datetime as dt

"""
Constants
"""
LOG_FILE = "/path/to/mc/server/logs/latest.log"
POLL_SLEEP = 5

EVENT_LOGIN = 0
EVENT_LOGOUT = 1

"""
Globals
"""
last_poll = dt.datetime.now()

"""
Utils
"""
def follow(name):
    current = open(name, "r")
    curino = os.fstat(current.fileno()).st_ino
    while True:
        while True:
            line = current.readline()
            if not line:
                break
            yield line

        try:
            if os.stat(name).st_ino != curino:
                new = open(name, "r")
                current.close()
                current = new
                curino = os.fstat(current.fileno()).st_ino
                continue
        except IOError:
            pass
        time.sleep(POLL_SLEEP)

def parse_line(line):
    line_part = line.split(']', 1)
    if len(line_part) == 1:
        return None, line

    line_date, line_info = line_part
    line_date = line_date.lstrip(' \t[')
    try:
        line_date = dt.datetime.strptime(line_date, '%d%b%Y %H:%M:%S.%f')
    except ValueError:
        return None, line

    return line_date, line_info

def get_activity_events():
    global last_poll

    log_file = follow(LOG_FILE)

    for line in log_file:
        tm, info = parse_line(line)
        if tm is None or tm <= last_poll:
            continue

        last_poll = tm

        if "net.minecraft.server.management.PlayerList" in info and "logged in" in info:
            yield {
                'time': tm,
                'raw': info,
                'event': EVENT_LOGIN,
                'data': {
                    'player': info.split(':')[1].split('[')[0].strip()
                }
            }
        elif "net.minecraft.network.play.ServerPlayNetHandler" in info and "lost connection" in info:
            yield {
                'time': tm,
                'raw': info,
                'event': EVENT_LOGOUT,
                'data': {
                    'player': info.split(':')[1].strip().split(' ')[0].strip(),
                    'reason': info.split(':')[-1].strip()
                }
            }


if __name__ == '__main__':
    for event in get_activity_events():
        print(event)

requirements.txt

aiohttp==3.7.3
async-timeout==3.0.1
attrs==20.3.0
chardet==3.0.4
discord.py==1.6.0
idna==3.1
idna-ssl==1.1.0
multidict==5.1.0
pkg-resources==0.0.0
typing-extensions==3.7.4.3
yarl==1.6.3