Flask+supervisor installation realizes background process resident

Flask+Supervisor Install to realize background process resident 

This time, we mainly try to run virtual machine Flask+Supervisor Background operation
Before flask demo Operation of , Only run when the task is started . In order to run in the background for a long time ,
You have to use Supervisor Only when the machine is switched on and off and the process is loaded and maintained can the local shutdown web page still be opened .

 Steps are as follows :

1. Open the created flask Environmental Science , newly build requirements.txt List all the flask Components
   pip install -r requirements.txt Here is the content

Flask==0.10.1
Flask-Login==0.2.11
Flask-Mail==0.9.1
Flask-Moment==0.4.0
Flask-PageDown==0.1.5
Flask-SQLAlchemy==2.0
Flask-Script==2.0.5
Flask-WTF==0.10.2
Flask-Cache==0.13.1
Flask-Restless==0.15.0
Flask-Uploads==0.1.3
Jinja2==2.7.3
Mako==1.0.0
Markdown==2.5.1
MarkupSafe==0.23
SQLAlchemy==0.9.8
WTForms==2.0.1
Werkzeug==0.9.6
html5lib==1.0b3
itsdangerous==0.24
six==1.8.0
awesome-slugify==1.6

2. loading uwsgi / gunicorn

   pip install uwsgi
   pip install gunicorn

3. Return to Flask Create... Under the project directory uwsgi.ini（ This is to use uwsgi Of , however gunicorn Simpler, it seems ）

[uwsgi]

# uwsgi  The address and port used when starting 
socket = 0.0.0.0:5000

#  Internet access port , If you use it directly uWSGI Extranet , Because of the use of Nginx, Therefore, it is noted out 
# http= :80

#  The site directory points to 
chdir = /root/projects/flask_car/

# python  Start program file 
wsgi-file = server.py

# python  To start in a program  application  Variable name 
# app  yes  manage.py  A variable in a program file , The type of this variable is  Flask Of  application  class 
callable = app

#  Number of processors 
processes = 4

#  Number of threads 
threads = 2

# State detection address 
stats = 0.0.0.0:9191

daemonize=/var/log/uwsgi.log

4. Run the command to install the configuration

   uwsgi config.ini

5. install Supervisor
   supervisor As a process guardian , To listen to web service , once web Hang up ,supervisor It will start itself . Make sure web The server will not be hung
   (1) Out of the environment deactivate
   （2） Install extended warehouse sudo yum install -y epel-release
   （3） install yum install -y supervisor
   （4） Check the installation position rpm -ql supervisor
   （5） find /etc/superisord.conf
   
   (6) Modify this file vim superisord.conf
   mkdir /etc/supervisor
   (7) By running echo_supervisord_conf Program generation supervisor Initialization profile for
   echo_supervisord_conf > /etc/supervisor/supervisord.conf
   （8） open /etc/supervisor/supervisord.conf The last line shows
   It's under this directory ini Will load , Then in /etc/supervisor.d Add one below

;[include]
;files = relative/directory/*.ini 
#  Add the following 
[include]
files = conf.d/*.conf

（9） Add a profile flask_car.conf To conf.d Under the table of contents

[program:flask_car]
#  Start command entry 
# command=flask/bin/uwsgi    ./uwsgi.ini
command=flask/bin/gunicorn -w 4 -b 0.0.0.0:5000 server:app
# command=flask/bin/python3  ./server.py

#  The directory where the command program is located 
directory=/root/projects/flask_car/
# The command to run the user name 
user=root

autostart=true
autorestart=true
# Log address 
stdout_logfile=/root/projects/flask_car/logs/uwsgi_supervisor.log
priority=1
killasgroup=true
stopasgroup=true

（10） start-up supervisor
supervisord -c /etc/supervisor/supervisord.conf
（11） Check the startup
ps -ef | grep supervisord

(12) If the relevant process has been started, kill and restart
kill -s SIGTERM 31333 Kill the first process Here you can see the startup

The port to take up Visible , If there is occupation, use kill The process number is ok

netstat -lntp   #  Check the port , If not, install net-tools Just input again 
yum -y install net-tools

(13) To configure Supervisor Boot up 

        newly build （ Rewrite if it exists ）/usr/lib/systemd/system/supervisord.service
				   
			```
			# dservice for systemd (CentOS 7.0+)
			# by ET-CS (https://github.com/ET-CS)
			[Unit]
			Description=Supervisor daemon
			
			[Service]
			Type=forking
			ExecStart=/usr/bin/supervisord  -c /etc/supervisor/supervisord.conf
			ExecStop=/usr/bin/supervisorctl shutdown
			ExecReload=/usr/bin/supervisorctl reload
			KillMode=process
			Restart=on-failure
			RestartSec=42s
			
			[Install]
			WantedBy=multi-user.target
			```

（14） Turn on and verify that it is turned on correctly

			- Carry out orders 
			systemctl enable supervisord
			- Or reload 
			systemctl daemon-reload
			- Validation command 
			systemctl is-enabled supervisord