Temporary failure in name resolution in Python script running during boot or on shutdown

I wrote a Python script which sends any message via Telegram: #!/opt/anaconda3/bin/python import asyncio import telegram import os import sys async def main(): bot = telegram.Bot(os.environ["TELEGRAM_TOKEN"]) async with bot: #print(await bot.get_me()) #print((await bot.get_updates())) await bot.send_message(text=' '.join(sys.argv[1:]), chat_id=MYCHATID) if __name__ == '__main__': asyncio.run(main()) TELEGRAM_TOKEN is set in /etc/environment, MYCHATID is hardcoded. Created two scripts to run it # cat /etc/init.d/sendbot_boot.sh #!/bin/bash /opt/anaconda3/bin/python /usr/local/bin/sendbot "Booting..." # cat /etc/init.d/sendbot_shutdown.sh #!/bin/bash /opt/anaconda3/bin/python /usr/local/bin/sendbot "Shutting down..." Added one of them to cron # cat /var/spool/cron/crontabs/root @reboot /etc/init.d/sendbot_boot.sh And another one to rc6. # ls -l /etc/rc6.d/K99sendbot_shutdown lrwxrwxrwx 1 root root 29 фев 10 02:08 /etc/rc6.d/K99sendbot_shutdown -> ../init.d/sendbot_shutdown.sh All scripts are executable and work well when I run them from terminal. But neither of them work on actual reboot. What I did wrong? # lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 18.04.6 LTS Release: 18.04 Codename: bionic *** I have grabbed error output and got: Traceback (most recent call last): File "/opt/anaconda3/lib/python3.8/site-packages/httpcore/_exceptions.py", line 10, in map_exceptions yield File "/opt/anaconda3/lib/python3.8/site-packages/httpcore/backends/asyncio.py", line 111, in connect_tcp stream: anyio.abc.ByteStream = await anyio.connect_tcp( File "/opt/anaconda3/lib/python3.8/site-packages/anyio/_core/_sockets.py", line 189, in connect_tcp gai_res = await getaddrinfo( File "/opt/anaconda3/lib/python3.8/site-packages/anyio/_core/_sockets.py", line 496, in getaddrinfo gai_res = await get_asynclib().getaddrinfo( File "/opt/anaconda3/lib/python3.8/site-packages/anyio/_backends/_asyncio.py", line 1754, in getaddrinfo result = await get_running_loop().getaddrinfo( File "/opt/anaconda3/lib/python3.8/asyncio/base_events.py", line 825, in getaddrinfo return await self.run_in_executor( File "/opt/anaconda3/lib/python3.8/concurrent/futures/thread.py", line 57, in run result = self.fn(*self.args, **self.kwargs) File "/opt/anaconda3/lib/python3.8/socket.py", line 918, in getaddrinfo for res in _socket.getaddrinfo(host, port, family, type, proto, flags): socket.gaierror: [Errno -3] Temporary failure in name resolution