选用 CentOS 7.5 版本部署 Flask 站点，需要安装的 Software Packages 有:
- nginx
- gunicorn
- supervisor
- flask
Nginx
Nginx是一个异步框架的Web服务器，也可以用作反向代理，负载均衡器和 HTTP 缓存。该软件由 Igor Sysoev 创建，并于2004年首次公开发布。
安装
# yum -y install epel-release
# yum -y install nginx
启动
# systemctl enable nginx
# systemctl start nginx
# systemctl status nginx
操作
在修改 nginx.conf 配置后，先测试修改后的配置文件是否正确。
# nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful
如果返回 ok, 再执行 nginx -s reload 重新加载配置文件。
默认的配置文件位于 /etc/nginx/nginx.conf, 也可以设置配置文件: nginx -c filename。
Gunicorn
Green Unicorn 是用于 UNIX 的 Python WSGI HTTP，是 pre-fork 多进程工作模型。
安装
# yum -y install python-pip
# pip install gunicorn
# pip install gevent
示例
# cat test.py
def app(environ, start_response):
"""Simplest possible application object"""
data = b'Hello Dragon!\n'
status = '200 OK'
response_headers = [
('Content-type', 'text/plain'),
('Content-Length', str(len(data)))
]
start_response(status, response_headers)
return iter([data])
# gunicorn --workers=2 test:app
Supervisor
Supervisor 是一个使用 Python 写的 C/S 架构的进程管理工具，它可以很方便的启动、停止、重启一个或多个进程。如果 Supervisor 管理的进程意外被杀死，它会将该进程重新拉起。
安装
# pip install supervisor
# yum -y install supervisor
启动
# systemctl enable supervisord
# systemctl start supervisord
Flask
Flask 是一个使用 Python 编写的轻量级 Web应用框架。基于 Werkzeug WSGI 工具箱和 Jinja2 模板引擎。
安装
# pip install Flask
Example
项目部署目录结构:
# mkdir -p /feiran/{etc,lib,log,run}
# tree /feiran
/feiran
├── etc
├── lib
├── log
└── run
项目命名为 dragon
# cat /feiran/lib/dragon/dragon.py
from flask import Flask
app = Flask("Dragon")
@app.route("/")
def dragon():
return "Hi, Dragon!"
if __name__ == '__main__':
app.debug = True
app.run()
使用 Supervisor 管理 Gunicorn 进程
# cat /etc/supervisord.d/dragon.ini
[program:dragon]
environment=PYTHONPATH='/feiran/lib/dragon'
stdout_logfile=/feiran/log/dragon_gunicorn.log
autostart=true
autorestart=unexpected
redirect_stderr=true
stopsignal=QUIT
command=gunicorn -c /feiran/etc/dragon_gunicorn.py dragon:app
Gunicorn 的配置文件, Async Workers:gevent
# cat /feiran/etc/dragon_gunicorn.py
import multiprocessing
workers = multiprocessing.cpu_count() * 2 + 1
worker_class = "gunicorn.workers.ggevent.GeventWorker"
worker_connections = 4096
# Wait keepalive connection for 30 seconds
keepalive = 30
timeout = 600
graceful_timeout = 12000
loglevel = "error"
access_logfile = "/feiran/log/dragon_gunicorn.log"
bind = ["unix:/feiran/run/dragon_gunicorn.sock", "0.0.0.0:8080"]
pidfile = "/feiran/run/dragon_gunicorn.pid"
执行 systemctl restart supervisord
执行 supervisorctl start dragon 启动 dragon 服务
执行 supervisorctl status dragon 查看 dragon 状态
最后一步,使用 Nginx 作为反向代理
# cat /etc/nginx/nginx.conf
# For more information on configuration, see:
# * Official English Documentation: http://nginx.org/en/docs/
# * Official Russian Documentation: http://nginx.org/ru/docs/
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
events {
worker_connections 1024;
}
http {
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
include /etc/nginx/mime.types;
default_type application/octet-stream;
upstream gunicorn {
server unix:/feiran/run/dragon_gunicorn.sock fail_timeout=5;
}
server {
listen 80 default_server;
listen [::]:80 default_server;
server_name _;
root /usr/share/nginx/html;
location / {
set $upstream 'gunicorn';
proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_pass http://$upstream;
}
error_page 404 /404.html;
location = /40x.html {
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
}
}
}
修改 nginx.conf 修改后，记得执行 nginx -t 和 nginx -s reload
测试 Flask 站点
Flask 站点上线后的目录结构
# tree /feiran/
/feiran/
├── etc
│ └── dragon_gunicorn.py
├── lib
│ └── dragon
│ ├── dragon.py
│ └── dragon.pyc
├── log
│ └── dragon_gunicorn.log
└── run
├── dragon_gunicorn.pid
└── dragon_gunicorn.sock
5 directories, 6 files
参考资料
http://nginx.org/en/docs/
https://gunicorn.org/
http://docs.gunicorn.org/en/stable/
http://supervisord.org/
http://flask.pocoo.org/
