server.py

#!/usr/bin/env python3

# This wrapper turns off the Python HTTP server's overly aggressive
# cache headers, which can get in the way of Verso hovers.

from http import server  # Python 3
from http.server import ThreadingHTTPServer, test
import os


class NonCachingHTTPRequestHandler(server.SimpleHTTPRequestHandler):
    def end_headers(self):
        self.send_my_headers()
        server.SimpleHTTPRequestHandler.end_headers(self)

    def send_my_headers(self):
        self.send_header("Cache-Control", "no-cache, no-store, must-revalidate")
        self.send_header("Pragma", "no-cache")
        self.send_header("Expires", "0")


if __name__ == "__main__":
    import argparse
    import contextlib

    parser = argparse.ArgumentParser()
    parser.add_argument(
        "-b",
        "--bind",
        metavar="ADDRESS",
        help="bind to this address (default: all interfaces)",
    )
    parser.add_argument(
        "-d",
        "--directory",
        default="_out/html-multi",
        help="serve this directory (default: _out/html-multi)",
    )
    parser.add_argument(
        "-p",
        "--protocol",
        metavar="VERSION",
        default="HTTP/1.0",
        help="conform to this HTTP version (default: %(default)s)",
    )
    parser.add_argument(
        "port",
        default=8000,
        type=int,
        nargs="?",
        help="bind to this port (default: %(default)s)",
    )
    args = parser.parse_args()

    # ensure dual-stack is not disabled; ref #38907
    class DualStackServer(ThreadingHTTPServer):
        def server_bind(self):
            # suppress exception when protocol is IPv4
            with contextlib.suppress(Exception):
                self.socket.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_V6ONLY, 0)
            return super().server_bind()

        def finish_request(self, request, client_address):
            self.RequestHandlerClass(
                request, client_address, self, directory=args.directory
            )

    print(args)

    test(
        HandlerClass=NonCachingHTTPRequestHandler,
        ServerClass=DualStackServer,
        port=args.port,
        bind=args.bind,
        protocol=args.protocol,
    )