Management command to set Django Site 1 domain to ngrok public url. In an app, add this file under `/management/commands/` as `ngrok.py`. Remember the `__init__.py` files. Run with `python manage.py ngrok`.

ngrok.py

import json
from urllib.request import urlopen

from django.contrib.sites.models import Site
from django.core.management.base import BaseCommand, CommandError


class Command(BaseCommand):
    help = 'Sets site domain to ngrok url and update telegram bot webhook'

    def handle(self, *args, **options):
        try:
            with urlopen("http://localhost:4040/api/tunnels") as conn:
                api_data = json.loads(conn.read().decode('utf-8'))
            tunnels = api_data['tunnels']
            ngrok_public_url = None
            for tunnel in tunnels:
                if tunnel['proto'] != 'https':
                    continue
                ngrok_public_url = tunnel['public_url'].replace('https://', '')
            assert ngrok_public_url is not None
        except Exception as e:
            raise CommandError("{}\nCould not find ngrok public url. "
                               "Did you remember to run `ngrok http $PORT`?".format(e))

        site = Site.objects.get(pk=1)
        site.domain = ngrok_public_url
        site.save()

        self.stdout.write(self.style.SUCCESS("Site 1 domain set to {}".format(ngrok_public_url)))