設定 Flask 應用程式 uWGSI Nginx - 伺服器配置鍋爐模板（預設代理和快取）

Created: November-22, 2018

這是來自 DigitalOcean 的如何在 Ubuntu 14.04 上使用 uWSGI 和 Nginx 服務 Flask 應用程式 的教程的移植 **

和 nginx 伺服器的一些有用的 git 資源。

Flask 應用

本教程假設你使用 Ubuntu。

找到 var/www/資料夾。
建立你的 Web 應用程式資料夾 mkdir myexample
cd myexample

可選你可能希望設定虛擬環境以在生產伺服器上部署 Web 應用程式。

sudo pip install virtualenv

安裝虛擬環境。

virtualenv myexample

為你的應用設定虛擬環境。

source myprojectenv/bin/activate

啟用你的環境。在這裡，你將安裝所有 python 包。

結束可選但推薦

設定 Flask 和閘道器 uWSGI

安裝 flask 和 uSWGI 閘道器：

pip install uwsgi flask

myexample.py 中的 Flask 應用示例：

from flask import Flask
application = Flask(__name__)

@application.route("/")
def hello():
    return "<h1>Hello World</h1>"

if __name__ == "__main__":
    application.run(host='0.0.0.0')

建立檔案以在你的 Web 應用程式和 Web 伺服器之間進行通訊：閘道器介面[ https://en.wikipedia.org/wiki/Web_Server_Gateway_Interface]

nano wsgi.py

然後匯入你的 webapp 模組並使其從閘道器入口點執行。

from myexample import application

if __name__ == "__main__":
    application.run()

測試 uWSGI：

uwsgi --socket 0.0.0.0:8000 --protocol=http -w wsgi

要配置 uWSGI：

建立配置檔案 .ini

nano myexample.ini
閘道器 uWSGI 的基本配置

# include header for using uwsgi
[uwsgi]
# point it to your python module wsgi.py
module = wsgi
# tell uWSGI to start a master node to serve requests
master = true
# spawn number of processes handling requests
processes = 5
# use a Unix socket to communicate with Nginx. Nginx will pass connections to uWSGI through a socket, instead of using ports. This is preferable because Nginx and uWSGI stays on the same machine.
socket = myexample.sock
# ensure file permission on socket to be readable and writable
chmod-socket = 660
# clean the socket when processes stop
vacuum = true
# use die-on-term to communicate with Ubuntu versions using Upstart initialisations: see:
# http://uwsgi-docs.readthedocs.io/en/latest/Upstart.html?highlight=die%20on%20term
die-on-term = true

如果你使用的是虛擬環境，則可選擇你可以使用虛擬環境。

Nginx 配置我們將使用 nginx：

預設伺服器使用 uwsgi 協議將請求傳遞給套接字
預設伺服器前的代理伺服器
快取伺服器以快取成功的請求（例如，你可能希望快取 GET 請求，如果你的 Web 應用程式）

找到 sites-available 目錄併為你的應用程式建立配置檔案：

sudo nano /etc/nginx/sites-available/myexample

新增以下塊，在註釋中它的作用：

server {
   

    # setting up default server listening to port 80
    listen 8000 default_server;
    server_name myexample.com; #you can also use your IP 
    
    # specify charset encoding, optional
    charset utf-8;

    # specify root of your folder directory
    root /var/www/myexample;

    # specify locations for your web apps.
    # here using /api endpoint as example
    location /api {
        # include parameters of wsgi.py and pass them to socket
        include uwsgi_params;
        uwsgi_pass unix:/var/www/myexample/myexample.sock;
    }

}

# Here you will specify caching zones that will be used by your virtual server
# Cache will be stored in /tmp/nginx folder
# ensure nginx have permissions to write and read there!
# See also:
# http://nginx.org/en/docs/http/ngx_http_proxy_module.html

proxy_cache_path /tmp/nginx levels=1:2 keys_zone=my_zone:10m inactive=60m;
proxy_cache_key "$scheme$request_method$host$request_uri";

# set up the virtual host!
server {
    listen   80  default_server;
    
    # Now www.example.com will listen to port 80 and pass request to http://example.com
    server_name www.example.com;

    # Why not caching responses

    location /api {
        # set up headers for caching
        add_header X-Proxy-Cache $upstream_cache_status;

        # use zone specified above
        proxy_cache my_zone;
        proxy_cache_use_stale updating;
        proxy_cache_lock on;
        
        # cache all responses ?
        # proxy_cache_valid 30d;

        # better cache only 200 responses :)
        proxy_cache_valid 200 30d;

        # ignore headers to make cache expire
        proxy_ignore_headers X-Accel-Expires Expires Cache-Control;

        # pass requests to default server on port 8000
        proxy_pass http://example.com:8000/api;
    }
}

最後，將檔案連結到 sites-enabled 目錄。有關可用站點和已啟用站點的說明，請參閱答案：[ http://serverfault.com/a/527644]

sudo ln -s /etc/nginx/sites-available/myproject /etc/nginx/sites-enabled

你現在已經完成了 nginx。但是，你可能想要檢視這個非常珍貴的鍋爐模板：[ https://github.com/h5bp/server-configs-nginx]

對微調非常有用。

現在測試 Nginx：

sudo nginx -t

啟動 Nginx：

sudo service nginx restart

自動化 Ubuntu 啟動 uWSGI 最後一件事是讓 Ubuntu 啟動 wsgi 閘道器與你的應用程式通訊，否則你應該手動完成。

在 Ubuntu 中找到初始化指令碼的目錄，並建立一個新指令碼：

sudo nano /etc/init/myexample.conf

新增以下塊，線上註釋以解釋它的作用

# description for the purpose of this script
description "uWSGI server instance configured to serve myproject"

# Tell to start on system runtime 2, 3, 4, 5. Stop at any other level (0,1,6). 
# Linux run levels: [http://www.debianadmin.com/debian-and-ubuntu-linux-run-levels.html]
start on runlevel [2345]
stop on runlevel [!2345]

# Set up permissions! "User" will be the username of your user account on ubuntu.
setuid user
# Allow www-data group to read and write from the socket file. 
# www-data is normally the group Nginx and your web applications belong to.
# you may have all web application projects under /var/www/ that belongs to www-data group
setgid www-data

# tell Ubunutu which environment to use.
# This is the path of your virtual environment: python will be in this path if you installed virtualenv. Otherwise, use path of your python installation
env PATH=/var/www/myexample/myexample/bin
# then tell to Ubuntu to change and locate your web application directory
chdir /var/www/myexample
# finally execute initialisation script, that load your web app myexample.py
exec uwsgi --ini myexample.ini

現在你可以啟用你的指令碼：sudo start myexample