Remove pidfile feature from server

Modern process managers (systemd, Docker) track PIDs themselves.
This was inherited gunicorn code for Type=forking systemd units,
but Plain's arbiter runs in the foreground where the PID is already
known to the supervisor.

Author: davegaeddert

plain/plain/cli/server.py

@@ -59,11 +59,6 @@
     setting="SERVER_ACCESS_LOG",
     help="Enable/disable access logging to stdout",
 )
-@click.option(
-    "--pidfile",
-    type=click.Path(),
-    help="PID file path",
-)
 def server(
     bind: tuple[str, ...],
     threads: int,
@@ -73,7 +68,6 @@ def server(
     keyfile: str | None,
     reload: bool,
     access_log: bool,
-    pidfile: str | None,
 ) -> None:
     """Production-ready HTTP server"""
     from plain.runtime import settings
@@ -98,7 +92,6 @@ def server(
         workers=workers,
         timeout=timeout,
         reload=reload,
-        pidfile=pidfile,
         certfile=certfile,
         keyfile=keyfile,
         accesslog=access_log,

plain/plain/server/README.md

@@ -69,7 +69,6 @@ Most options can also be configured via settings (see below). CLI arguments take
 | `--reload`                       | -                   | Restart workers on code changes      |
 | `--certfile`                     | -                   | Path to SSL certificate file         |
 | `--keyfile`                      | -                   | Path to SSL key file                 |
-| `--pidfile`                      | -                   | PID file path                        |
 
 ## Settings
 

plain/plain/server/app.py

@@ -25,7 +25,6 @@ def __init__(
         threads: int,
         timeout: int,
         reload: bool,
-        pidfile: str | None,
         certfile: str | None,
         keyfile: str | None,
         accesslog: bool,
@@ -35,7 +34,6 @@ def __init__(
         self.threads = threads
         self.timeout = timeout
         self.reload = reload
-        self.pidfile = pidfile
         self.certfile = certfile
         self.keyfile = keyfile
         self.accesslog = accesslog

plain/plain/server/arbiter.py

@@ -22,7 +22,6 @@
 
 from . import sock
 from .errors import APP_LOAD_ERROR, WORKER_BOOT_ERROR, HaltServer
-from .pidfile import Pidfile
 from .workers.entry import worker_main
 from .workers.thread import check_worker_config
 from .workers.workertmp import WorkerHeartbeat
@@ -55,8 +54,6 @@ def __init__(self, app: ServerApplication):
         self.timeout: int = app.timeout
         self.pid: int = os.getpid()
         self.worker_age: int = 0
-        self.pidfile: Pidfile | None = None
-
         self._workers: dict[int, WorkerInfo] = {}
         self._listeners: list[sock.BaseSocket] = []
         self._shutdown_event = threading.Event()
@@ -90,16 +87,10 @@ def run(self) -> None:
         except Exception:
             self.log.error("Unhandled exception in main loop", exc_info=True)
             self._stop(graceful=False)
-            if self.pidfile is not None:
-                self.pidfile.unlink()
             sys.exit(-1)
 
     def _start(self) -> None:
-        """Initialize the arbiter. Start listening and set pidfile if needed."""
-        if self.app.pidfile is not None:
-            self.pidfile = Pidfile(self.app.pidfile)
-            self.pidfile.create(self.pid)
-
+        """Initialize the arbiter. Start listening."""
         # SIGTERM = graceful shutdown, SIGINT/SIGQUIT = immediate shutdown
         signal.signal(signal.SIGTERM, self._handle_signal)
         signal.signal(signal.SIGINT, self._handle_hard_stop)
@@ -135,8 +126,6 @@ def _halt(
         if reason is not None:
             log_func("Reason: %s", reason)
 
-        if self.pidfile is not None:
-            self.pidfile.unlink()
         sys.exit(exit_status)
 
     def _stop(self, graceful: bool = True) -> None: