如何在Flask应用程序退出时停止Gunicorn

我正在使用gunicorn来运行我的Flask应用程序，但是当Flask应用程序由于错误而退出时，gunicorn将创建一个新的worker并且不会退出。如何在Flask应用程序退出时停止Gunicorn

试瓶的应用：

$ vim app.py 

# main file 
import sys 
import os 
import logging 
from flask import Flask 

from views import views 

def create_app(): 

    app = Flask(__name__) 

    app_name = os.environ.get('FLASK_APP_NAME', None) 
    if app_name is None: 
     logging.error("Failed to load configuration") 
     sys.exit(2) 

    app.config['APP_NAME'] = app_name 

    console = logging.StreamHandler(sys.stdout) 
    logging.getLogger().addHandler(console) 
    logging.getLogger().setLevel(logging.INFO) 

    logging.info("Starting Flask application") 

    app.register_blueprint(views) 

    return app 

app = create_app() 

if __name__ == '__main__': 
    app.run(host='0.0.0.0', port=8000, debug=False, threaded=True) 


$ vim views.py 

# views 
from flask import request, jsonify, Blueprint 
from flask import current_app as app 

views = Blueprint('views', __name__) 

@views.route("/", methods=["GET"]) 
def indexz(): 
    return jsonify(app=app.config['APP_NAME'], msg='OK'), 200

我试着用gunicorn的worker_exit服务器挂钩：

$ vim gunicorn-config.py 

import sys 

workers = 2 

def worker_exit(server, worker): 
    sys.exit(2) 
    # server.halt()

但这只是抛出一个错误，并继续产卵工人：

# error when using sys.exit(2) 
[2016-12-10 01:28:53 +0000] [11916] [INFO] Booting worker with pid: 11916 
ERROR:root:Failed to load configuration 
[2016-12-10 01:28:53 +0000] [11915] [INFO] Worker exiting (pid: 11915) 
[2016-12-10 01:28:53 +0000] [11915] [WARNING] Exception during worker exit: 
Traceback (most recent call last): 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 576, in spawn_worker 
    self.cfg.worker_exit(self, worker) 
    File "gunicorn-config.py", line 6, in worker_exit 
    sys.exit(2) 
SystemExit: 2 


# error when using server.halt() 
[2016-12-10 01:30:15 +0000] [12202] [INFO] Booting worker with pid: 12202 
ERROR:root:Failed to load configuration 
[2016-12-10 01:30:15 +0000] [12197] [INFO] Worker exiting (pid: 12197) 
[2016-12-10 01:30:15 +0000] [12197] [INFO] Shutting down: Master 
[2016-12-10 01:30:15 +0000] [12197] [WARNING] Exception during worker exit: 
Traceback (most recent call last): 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 576, in spawn_worker 
    self.cfg.worker_exit(self, worker) 
    File "gunicorn-config.py", line 7, in worker_exit 
    server.halt() 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 331, in halt 
    self.stop() 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 378, in stop 
    self.kill_workers(sig) 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 600, in kill_workers 
    self.kill_worker(pid, sig) 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 616, in kill_worker 
    self.cfg.worker_exit(self, worker) 
    File "gunicorn-config.py", line 7, in worker_exit 
    server.halt() 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 338, in halt 
    sys.exit(exit_status) 
SystemExit: 0

编辑：将我的应用程序的退出代码修改为：sys.exit(4)根据https://github.com/benoitc/gunicorn/blob/master/gunicorn/arbiter.py#L37。这一次的应用程序不会无限重启，但是当有2名或更多的工人，这将引发异常：

[2016-12-10 18:45:52 +0000] [22195] [INFO] Worker exiting (pid: 22195) 
Traceback (most recent call last): 
    File "/usr/bin/gunicorn", line 11, in <module> 
    sys.exit(run()) 
    File "/usr/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py", line 74, in run 
    WSGIApplication("%(prog)s [OPTIONS] [APP_MODULE]").run() 
    File "/usr/lib/python2.7/site-packages/gunicorn/app/base.py", line 192, in run 
    super(Application, self).run() 
    File "/usr/lib/python2.7/site-packages/gunicorn/app/base.py", line 72, in run 
    Arbiter(self).run() 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 218, in run 
    self.halt(reason=inst.reason, exit_status=inst.exit_status) 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 331, in halt 
    self.stop() 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 381, in stop 
    time.sleep(0.1) 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 231, in handle_chld 
    self.reap_workers() 
    File "/usr/lib/python2.7/site-packages/gunicorn/arbiter.py", line 506, in reap_workers 
    raise HaltServer(reason, self.WORKER_BOOT_ERROR) 
gunicorn.errors.HaltServer: <HaltServer 'Worker failed to boot.' 3>

我怎样才能让没有任何例外的应用程序退出被触发。

来源

2016-12-10 Python Novice

你试图创建try-except块来捕获异常，并在杀死gunicorn除块？ –

我在哪里可以放入这个try/except块？ –

看看gunicorn配置中的preload_app选项。这会将您的应用程序加载到父项中。然后它应该能够引发异常并且gunicorn不会启动。

来源

2016-12-10 20:32:31

预加载不能用于我的应用程序 –

使用预加载选项时出现了什么问题？ –

这将退出gunicorn：

os._exit(4)

来源

2017-09-21 00:35:05

如何在Flask应用程序退出时停止Gunicorn

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