Add a config and command line argument to daemonise the workers

This is often something users wish to control as some environments
don't support daemon processes.

Author: pgjones

src/hypercorn/__main__.py

@@ -61,6 +61,13 @@ def main(sys_args: list[str] | None = None) -> int:
         help="Location of a TOML config file, or when prefixed with `file:` a Python file, or when prefixed with `python:` a Python module.",  # noqa: E501
         default=None,
     )
+    parser.add_argument(
+        "-D",
+        "--daemon",
+        help="Run the workers as daemons",
+        action="store_true",
+        default=sentinel,
+    )
     parser.add_argument(
         "--debug",
         help="Enable debug mode, i.e. extra logging and checks",
@@ -240,6 +247,8 @@ def _convert_verify_mode(value: str) -> ssl.VerifyMode:
         config.cert_reqs = args.cert_reqs
     if args.ciphers is not sentinel:
         config.ciphers = args.ciphers
+    if args.daemon is not sentinel:
+        config.daemon = args.daemon
     if args.debug is not sentinel:
         config.debug = args.debug
     if args.error_log is not sentinel:

src/hypercorn/config.py

@@ -71,6 +71,7 @@ class Config:
     ca_certs: str | None = None
     certfile: str | None = None
     ciphers: str = "ECDHE+AESGCM"
+    daemon = True
     debug = False
     dogstatsd_tags = ""
     errorlog: logging.Logger | str | None = "-"

src/hypercorn/run.py

@@ -121,7 +121,7 @@ def _populate(
             target=worker_func,
             kwargs={"config": config, "shutdown_event": shutdown_event, "sockets": sockets},
         )
-        process.daemon = True
+        process.daemon = config.daemon
         try:
             process.start()
         except PicklingError as error: