app.py

from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
from pathlib import Path
import os


class Handler(SimpleHTTPRequestHandler):
    def do_GET(self):
        if self.path in {"", "/"}:
            self.path = "/index.html"
        return super().do_GET()

    def end_headers(self):
        self.send_header("Cache-Control", "public, max-age=60")
        super().end_headers()


if __name__ == "__main__":
    os.chdir(Path(__file__).resolve().parent)
    port = int(os.environ.get("PORT", "7860"))
    server = ThreadingHTTPServer(("0.0.0.0", port), Handler)
    server.serve_forever()