Flaskアプリケーションが終了したときにGunicornを停止する方法

Question

Flaskアプリケーションを実行するためにgunicornを使用していますが、Flaskアプリケーションがエラーで終了すると、gunicornは新しいワーカーを作成し、終了しません。

サンプルフラスコアプリケーション：

$ vim gunicorn-config.py 

import sys 

workers = 2 

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

しかし、これは単にエラーをスローし、労働者を起動し続けて：

$ 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 

私はgunicornのworker_exitサーバーのフックを使用してみました

# 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 

編集：アプリケーションの終了コードをに変更しました。https://github.com/benoitc/gunicorn/blob/master/gunicorn/arbiter.py#L37。この時間は、アプリケーションが無限ではない再起動を行いますが、2人の以上の労働者がある場合、これは例外をスロー：

[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> 

はどのようにしてトリガーされ、例外なく、アプリケーションの終了を行うことができます。

Answer 1

gunicorn設定のpreload_appオプションをご覧ください。これはあなたのアプリケーションを親にロードします。その場合、例外を発生させる可能性があり、gunicornは起動しません。

Answer 2

これはgunicornを終了します。

os._exit(4)