server.py

import socket
import argparse
from pathlib import Path
import os

CRLF = b"\r\n"
PATH = "files/"

def handle_client(conn, addr, root: Path, timeout: float):
    conn.settimeout(timeout)

    try:
        # Get Request from client
        request = conn.recv(1024).decode().split()
        good_request = True
        # Verify Request
        if request[0] != "GET" or request[2] != "HTTP/1.1":
            good_request = False
            try:
                conn.sendall(b"ERR 400 bad-request")
            except Exception:
                pass

        # Retrieve file to send back
        if good_request:
            try:
                file = open(f"{PATH}{request[1]}")
                file_contents = file.read()
            except:
                good_request = False #terminate
                conn.send(b"ERR 404 not-found")
            # send file to client, file is in "root" folder
            # file can be sent as "text", no need to use bytes
            # See TCPClient/TCPServer on sending text
            # add error handling in case file is not found
            if good_request:
                encoded_file = file_contents.encode()
                file_size = len(encoded_file)
                conn.sendall(f"HTTP/1.1 200 OK\nContent-Length:{file_size}\r\n\r\n".encode())
                for i in range(file_size):
                    conn.send(encoded_file[i:i+1])
                # Send CRLF at the end if the file
                conn.send(CRLF)
            

    # handle timeout message
    except socket.timeout:
        try:
            conn.sendall(b"ERR 400 timeout\r\n")
        except Exception:
            pass
    # handle general exceptions
    except Exception:
        try:
            conn.sendall(b"ERR 500 server-error\r\n")
        except Exception:
            pass
    finally:
        conn.close()



def serve(host: str, port: int, root: Path, workers: int, timeout: float):
    root = root.resolve()

    # Create a socket in a python context manager
    # The socket is opened using IPV4 and TCP
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        
        # Bind socket to ip address and port
        s.bind((host, port))
        
        # Start listening
        s.listen()
        print(f"[HTTP server] Serving {root} on {host}:{port}")
        
        while True:
            conn, addr = s.accept()
            handle_client(conn, addr, root, timeout)


if __name__ == "__main__":
    p = argparse.ArgumentParser(description="TinyFile server")
    p.add_argument("--host", default="0.0.0.0")
    p.add_argument("--port", type=int, default=9009)
    p.add_argument("--root", type=Path, default=Path("files"))
    p.add_argument("--timeout", type=float, default=10.0)
    args = p.parse_args()

    args.root.mkdir(parents=True, exist_ok=True)
    serve(args.host, args.port, args.root, workers=100, timeout=args.timeout)