Caddy frontend for django manage.py.

manage.py

import os
import sys

HERE = os.path.dirname(__file__)

# Stolen from a SO answer
def get_free_port():
    import socket
    import contextlib

    with contextlib.closing(socket.socket(socket.AF_INET, socket.SOCK_STREAM)) as s:
        s.bind(('localhost', 0))
        return s.getsockname()[1]

# Mostly stolen from some of the runserver internals
def runserver_to_caddy_args():
    import re
    from django.core.management.commands.runserver import Command, naiveip_re

    ret_args = []

    argv = list(sys.argv)
    cmd = Command()
    parser = cmd.create_parser(argv[0], argv[1])
    options = parser.parse_args(argv[2:])

    use_ipv6 = options.use_ipv6

    if not options.addrport:
        addr = ''
        port = cmd.default_port
    else:
        m = re.match(naiveip_re, options.addrport)
        if m is None:
            raise Exception(f"{options.addrport} is not valid port or addr:port")

        addr, _ipv4, _ipv6, _fqdn, port = m.groups()
        if not port.isdigit():
            raise Exception(f"{port} is not valid port")

        if addr:
            if _ipv6:
                addr = addr[1:-1]
                use_ipv6 = True
            elif use_ipv6 and not _fqdn:
                raise Exception(f"{addr} is not a valid ipv6 address")

    if not addr:
        addr = '::1' if use_ipv6 else '127.0.0.1'

    free_local_port = get_free_port()
    new_addrport = f'localhost:{free_local_port}'
    # replace the command line address

    if options.addrport:
        try:
            # Replace if possible
            argv[argv.index(options.addrport)] = new_addrport
        except ValueError:
            # .index can raise ValueError, in which case we will ignore
            pass
    else:
        argv.append(new_addrport)


    crt_path = os.path.join(HERE, 'etc', 'localhost.crt')
    key_path = os.path.join(HERE, 'etc', 'localhost.key')

    ret_args.extend(('-host', addr))
    ret_args.extend(('-port', port))
    ret_args.extend((
        f'proxy / {new_addrport}',
        f'tls {crt_path} {key_path}',
    ))
    ret_args.extend(('log stdout',))
    return ret_args, argv

def main(*args):
    os.environ['DJANGO_SETTINGS_MODULE'] = 'settings'
    from django.core import management

    args = list(args)

    if 'runserver' in args and os.environ.get('RUN_MAIN') == 'true':
        import subprocess
        import atexit

        caddy_args, args = runserver_to_caddy_args()

        p = subprocess.Popen(
            ['caddy', *caddy_args],
            cwd = os.getcwd(),
            env = os.environ,
            stdout = sys.stdout,
            stderr = sys.stderr,
        )
        def kill():
            print("KILLING")
            p.kill()
        atexit.register(kill)

    management.execute_from_command_line(*args)

if __name__ == '__main__':
    main(*sys.argv)