platypush/platypush/runner/_runner.py

101 lines
2.6 KiB
Python

import logging
import os
import signal
import sys
from threading import Thread
from typing import Optional
from platypush.cli import parse_cmdline
from platypush.commands import CommandStream
from ._app import ApplicationProcess
class ApplicationRunner:
"""
Runner for the main application.
It wraps the main application and provides an interface to control it
externally.
"""
_default_timeout = 0.5
def __init__(self):
logging.basicConfig(level=logging.INFO, stream=sys.stdout)
self.logger = logging.getLogger('platypush:runner')
self._proc: Optional[ApplicationProcess] = None
self._stream: Optional[CommandStream] = None
def _listen(self, stream: CommandStream):
"""
Listens for external application commands and executes them.
"""
while self.is_running:
cmd = stream.read(timeout=self._default_timeout)
if not cmd:
continue
self.logger.info(cmd)
Thread(target=cmd, args=(self,)).start()
def _print_version(self):
from platypush import __version__
print(__version__)
sys.exit(0)
def _run(self, *args: str) -> None:
parsed_args = parse_cmdline(args)
if parsed_args.version:
self._print_version()
signal.signal(signal.SIGTERM, lambda *_: self.stop())
while True:
with CommandStream(
parsed_args.ctrl_sock
) as self._stream, ApplicationProcess(
*args, pidfile=parsed_args.pidfile, timeout=self._default_timeout
) as self._proc:
try:
self._listen(self._stream)
except KeyboardInterrupt:
pass
if self.should_restart:
self.logger.info('Restarting application...')
continue
break
self._stream = None
def run(self, *args: str) -> None:
try:
self._run(*args)
finally:
self._proc = None
def stop(self):
if self._proc is not None:
self._proc.stop()
if self._stream and self._stream.pid:
os.kill(self._stream.pid, signal.SIGKILL)
self._stream = None
def restart(self):
if self._proc is not None:
self._proc.mark_for_restart()
self.stop()
@property
def is_running(self) -> bool:
return bool(self._proc and self._proc.is_alive())
@property
def should_restart(self) -> bool:
return self._proc.should_restart if self._proc is not None else False