Setting up Django and your web server with uWSGI and nginx

写在最前:
此文章是直接把uWSGI的教程弄下来了,这是最靠谱的教程了,但是自己弄的时候还是遇到了一些坑,最终通过自己的摸索终于完成了服务器的搭建,特写此文帮助各位和我一样的新手快速爬坑.
Setting up Django and your web server with uWSGI and nginx — uWSGI 2.0 documentation
感谢@Corssin先生的提点和他的教程带我入门,请关注微信公众号“Crossin的编程教室”.

环境:Ubuntu 18.04.1 LTS (GNU/Linux 4.15.0-38-generic x86_64)
[腾讯云服务器,默认系统是16,给升级了]
Python 3.6.6
(自带的,Ubuntu 16自带3.5应该没有影响)

以后文章中有需要注意的地方都会用这种形式写出来

请先行了解Linux的用户、用户组和文件权限的相关概念,不然到后面你会很痛苦.
关于Django,建议现在自己的电脑上按照官网的教程完整走一遍再来学习部署服务器.
所有的操作不建议在~目录下进行,先切换到/目录(看你方便,新手还是在/下最省事,就是不建议在任何用户目录里,不然权限问题又是个大坑).

This tutorial is aimed at the Django user who wants to set up a production web server. It takes you through the steps required to set up Django so that it works nicely with uWSGI and nginx. It covers all three components, providing a complete stack of web application and server software.

Django is a high-level Python Web framework that encourages rapid development and clean, pragmatic design.

nginx (pronounced engine-x ) is a free, open-source, high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server.

Some notes about this tutorial

Note

This is a tutorial. It is not intended to provide a reference guide, never mind an exhaustive reference, to the subject of deployment.

nginx and uWSGI are good choices for Django deployment, but they are not the only ones, or the ‘official’ ones. There are excellent alternatives to both, and you are encouraged to investigate them.

The way we deploy Django here is a good way, but it is not the only way; for some purposes it is probably not even the best way.

It is however a reliable and easy way, and the material covered here will introduce you to concepts and procedures you will need to be familiar with whatever software you use for deploying Django. By providing you with a working setup, and rehearsing the steps you must take to get there, it will offer you a basis for exploring other ways to achieve this.

Note

This tutorial makes some assumptions about the system you are using.

It is assumed that you are using a Unix-like system, and that it features an aptitude-like package manager. However if you need to ask questions like “What’s the equivalent of aptitude on Mac OS X?”, you’ll be able to find that kind of help fairly easily.

While this tutorial assumes Django 1.4 or later, which will automatically create a wsgi module in your new project, the instructions will work with earlier versions. You will though need to obtain that Django wsgi module yourself, and you may find that the Django project directory structure is slightly different.

Concept

A web server faces the outside world. It can serve files (HTML, images, CSS, etc) directly from the file system. However, it can’t talk directly to Django applications; it needs something that will run the application, feed it requests from web clients (such as browsers) and return responses.

A Web Server Gateway Interface - WSGI - does this job. WSGI is a Python standard.

uWSGI is a WSGI implementation. In this tutorial we will set up uWSGI so that it creates a Unix socket, and serves responses to the web server via the uwsgi protocol. At the end, our complete stack of components will look like this:

the web client <-> the web server <-> the socket <-> uwsgi <-> Django

Before you start setting up uWSGI

virtualenv

Make sure you are in a virtualenv for the software we need to install (we will describe how to install a system-wide uwsgi later):

cd /
virtualenv uwsgi-tutorial #尝试sudo python3 -m venv uwsgi-tutorial
cd uwsgi-tutorial
source bin/activate

个人认为虚拟环境是必须的,因为倒数第二步有需要用到这个虚拟环境的地方.
如果你用python3 而且需要用python3命令来启动的更是需要
尝试sudo python3 -m venv uwsgi-tutorial
如果缺少东西的话会提示你,按照说明安装了就可以了.
记得切换到/目录哟

Django

Install Django into your virtualenv, create a new project, and cd into the project:

同样在/目录下哟

pip install Django
django-admin.py startproject mysite
cd mysite

About the domain and port

In this tutorial we will call your domain example.com. Substitute your own FQDN or IP address.

Throughout, we’ll be using port 8000 for the web server to publish on, just like the Django runserver does by default. You can use whatever port you want of course, but I have chosen this one so it doesn’t conflict with anything a web server might be doing already.

Basic uWSGI installation and configuration

Install uWSGI into your virtualenv

pip install uwsgi

Of course there are other ways to install uWSGI, but this one is as good as any. Remember that you will need to have Python development packages installed. In the case of Debian, or Debian-derived systems such as Ubuntu, what you need to have installed is pythonX.Y-dev, where X.Y is your version of Python.

如果安装uwsgi报错的话就要安装开发包,⬆️

Basic test

Create a file called test.py:

这里我是吧这个文件放到了/mysite/目录下了,看你自己

# test.py
def application(env, start_response):
    start_response('200 OK', [('Content-Type','text/html')])
    return [b"Hello World"] # python3
    #return ["Hello World"] # python2

Note

Take into account that Python 3 requires bytes().

Run uWSGI:

uwsgi --http :8000 --wsgi-file test.py

使用云服务器记得把这个端口放通哦

The options mean:

• http :8000: use protocol http, port 8000
• wsgi-file test.py: load the specified file, test.py
  This should serve a ‘hello world’ message directly to the browser on port 8000. Visit:

http://example.com:8000

to check. If so, it means the following stack of components works:

the web client <-> uWSGI <-> Python

Test your Django project

Now we want uWSGI to do the same thing, but to run a Django site instead of the test.py module.

If you haven’t already done so, make sure that your mysite project actually works:

python manage.py runserver 0.0.0.0:8000

And if that works, run it using uWSGI:

uwsgi --http :8000 --module mysite.wsgi

• module mysite.wsgi: load the specified wsgi module
  Point your browser at the server; if the site appears, it means uWSGI is able to serve your Django application from your virtualenv, and this stack operates correctly:

the web client <-> uWSGI <-> Django

Now normally we won’t have the browser speaking directly to uWSGI. That’s a job for the webserver, which will act as a go-between.

一个老问题,如果访问页面没有小火箭而是报错,请把你的服务器ip(看报错说明)填入setting.py文件中.

Basic nginx

Install nginx

sudo apt-get install nginx
sudo /etc/init.d/nginx start    # start nginx

And now check that nginx is serving by visiting it in a web browser on port 80 - you should get a message from nginx: “Welcome to nginx!”. That means these components of the full stack are working together:

the web client <-> the web server

If something else is already serving on port 80 and you want to use nginx there, you’ll have to reconfigure nginx to serve on a different port. For this tutorial though, we’re going to be using port 8000.

Configure nginx for your site

You will need the uwsgi_params file, which is available in the nginx directory of the uWSGI distribution, or from https://github.com/nginx/nginx/blob/master/conf/uwsgi_params

uwsgi_params复制到你的工程目录,也就是/mysite/

Copy it into your project directory. In a moment we will tell nginx to refer to it.

Now create a file called mysite_nginx.conf in the etc_nginx_sites-available directory, and put this in it:

这里叫你在/etc/nginx/sites-available/下创建这个文件,我不建议你这样做,而是按下面文章说的方法,“把它放在你的工程目录里”/mysite/mysite_nginx.conf

# mysite_nginx.conf

# the upstream component nginx needs to connect to
upstream django {
    # server unix:///path/to/your/mysite/mysite.sock; # for a file socket
    server 127.0.0.1:8001; # for a web port socket (we'll use this first)这里不要改哟,最后也用不到这个
}

# configuration of the server
server {
    # the port your site will be served on
    listen      8000;
    # the domain name it will serve for
    server_name example.com; # substitute your machine's IP address or FQDN*****这里要改*****
    charset     utf-8;

    # max upload size
    client_max_body_size 75M;   # adjust to taste

    # Django media
    location /media  {
        alias /path/to/your/mysite/media;  # your Django project's media files - amend as required*****这里要改*****,如果按照我说的来也就是alias /mysite/media
    }

    location /static {
        alias /path/to/your/mysite/static; # your Django project's static files - amend as required*****这里要改***** alias /mysite/static
    }

    # Finally, send all non-media requests to the Django server.
    location / {
        uwsgi_pass  django;
        include     /path/to/your/mysite/uwsgi_params; # the uwsgi_params file you installed*****这里要改***** include /mysite/uwsgi_params
    }
}

This conf file tells nginx to serve up media and static files from the filesystem, as well as handle requests that require Django’s intervention. For a large deployment it is considered good practice to let one server handle static/media files, and another handle Django applications, but for now, this will do just fine.

Symlink to this file from _etc_nginx/sites-enabled so nginx can see it:

sudo ln -s ~/path/to/your/mysite/mysite_nginx.conf /etc/nginx/sites-enabled/

使用软连接 ln -s时最好第一个参数使用绝对路径,不然容易出错,以后无论在哪里也都推荐这样做,即使你已经在当前文件夹
sudo ln -s /mysite/mysite_nginx.conf /etc/nginx/sites-enabled

Deploying static files

Before running nginx, you have to collect all Django static files in the static folder. First of all you have to edit mysite/settings.py adding:

STATIC_ROOT = os.path.join(BASE_DIR, "static/")

and then run

python manage.py collectstatic

Basic nginx test

Restart nginx:

sudo /etc/init.d/nginx restart

To check that media files are being served correctly, add an image called media.png to the /path/to/your/project/project/media directory, then visit http://example.com:8000/media/media.png - if this works, you’ll know at least that nginx is serving files correctly.

It is worth not just restarting nginx, but actually stopping and then starting it again, which will inform you if there is a problem, and where it is.

nginx and uWSGI and test.py

Let’s get nginx to speak to the “hello world” test.py application.

uwsgi --socket :8001 --wsgi-file test.py

This is nearly the same as before, except this time one of the options is different:

• socket :8001: use protocol uwsgi, port 8001
  nginx meanwhile has been configured to communicate with uWSGI on that port, and with the outside world on port 8000. Visit:

http://example.com:8000/

to check. And this is our stack:

the web client <-> the web server <-> the socket <-> uWSGI <-> Python

Meanwhile, you can try to have a look at the uswgi output at http://example.com:8001 - but quite probably, it won’t work because your browser speaks http, not uWSGI, though you should see output from uWSGI in your terminal.

Using Unix sockets instead of ports

So far we have used a TCP port socket, because it’s simpler, but in fact it’s better to use Unix sockets than ports - there’s less overhead.

Edit mysite_nginx.conf, changing it to match:

server unix:///path/to/your/mysite/mysite.sock; # for a file socket ***改成这样** server unix:///mysite/mysite.sock
# server 127.0.0.1:8001; # for a web port socket (we'll use this first)

and restart nginx.

Run uWSGI again:

uwsgi --socket mysite.sock --wsgi-file test.py

This time the socket option tells uWSGI which file to use.

Try http://example.com:8000/ in the browser.

这里一般开始就容易出错了,请看官网的解决办法

If that doesn’t work

Check your nginx error log(_var_log_nginx_error.log). If you see something like:

connect() to unix:///path/to/your/mysite/mysite.sock failed (13: Permission
denied)

then probably you need to manage the permissions on the socket so that nginx is allowed to use it.

Try:

uwsgi --socket mysite.sock --wsgi-file test.py --chmod-socket=666 # (very permissive)

亲测还是需要666权限,应为nginx默认没有用户,所以最后的6权限还是需要的,而不是4
or:

uwsgi --socket mysite.sock --wsgi-file test.py --chmod-socket=664 # (more sensible)

You may also have to add your user to nginx’s group (which is probably www-data), or vice-versa, so that nginx can read and write to your socket properly.

It’s worth keeping the output of the nginx log running in a terminal window so you can easily refer to it while troubleshooting.

Running the Django application with uwsgi and nginx

Let’s run our Django application:

uwsgi --socket mysite.sock --module mysite.wsgi --chmod-socket=664

还是用666权限哟

Now uWSGI and nginx should be serving up not just a “Hello World” module, but your Django project.

Configuring uWSGI to run with a .ini file

We can put the same options that we used with uWSGI into a file, and then ask uWSGI to run with that file. It makes it easier to manage configurations.

Create a file called mysite_uwsgi.ini:

同样也放在/mysite/下

# mysite_uwsgi.ini file
[uwsgi]

# Django-related settings
# the base directory (full path)
# 这里就是放工程路径  /mysite/
chdir           = /path/to/your/project
# Django's wsgi file
# wsgi模块,他是在/mysite/mysite/wsgi.py,所以就改成mysite.wsgi
module          = project.wsgi
# the virtualenv (full path)
# 这里放python的虚拟环境, /uwsgi-tutorial
home            = /path/to/virtualenv

# process-related settings
# master
master          = true
# maximum number of worker processes
processes       = 10
# the socket (use the full path to be safe
# 这里socket改成/mysite/mysite.sock
socket          = /path/to/your/project/mysite.sock
# ... with appropriate permissions - may be needed
# chmod-socket需要取消注释,并且改成666
# chmod-socket    = 664
# clear environment on exit
vacuum          = true

And run uswgi using this file:

uwsgi --ini mysite_uwsgi.ini # the --ini option is used to specify a file

Once again, test that the Django site works as expected.

这样来测试一般不会有什么问题

Install uWSGI system-wide

So far, uWSGI is only installed in our virtualenv; we’ll need it installed system-wide for deployment purposes.

Deactivate your virtualenv:

deactivate

and install uWSGI system-wide:

sudo pip install uwsgi

# Or install LTS (long term support).
pip install https://projects.unbit.it/downloads/uwsgi-lts.tar.gz

千万记得加sudo或者sudo python3 -m pip install uwsgi
不加sudo就会安装到~/.local 这类的文件夹下,然后就是一堆权限问题

The uWSGI wiki describes several installation procedures. Before installing uWSGI system-wide, it’s worth considering which version to choose and the most apppropriate way of installing it.

Check again that you can still run uWSGI just like you did before:

uwsgi --ini mysite_uwsgi.ini # the --ini option is used to specify a file

用sudo安装的uwsgi一般不会出问题

Emperor mode

“皇帝模式”,我喜欢这个名字
uWSGI can run in ‘emperor’ mode. In this mode it keeps an eye on a directory of uWSGI config files, and will spawn instances (‘vassals’) for each one it finds.

Whenever a config file is amended, the emperor will automatically restart the vassal.

# create a directory for the vassals
sudo mkdir /etc/uwsgi
sudo mkdir /etc/uwsgi/vassals
# symlink from the default config directory to your config file
sudo ln -s /path/to/your/mysite/mysite_uwsgi.ini /etc/uwsgi/vassals/
# run the emperor
uwsgi --emperor /etc/uwsgi/vassals --uid www-data --gid www-data

You may need to run uWSGI with sudo:

sudo uwsgi --emperor /etc/uwsgi/vassals --uid www-data --gid www-data

The options mean:

• emperor: where to look for vassals (config files)
• uid: the user id of the process once it’s started
• gid: the group id of the process once it’s started
  Check the site; it should be running.

现在开始服务器报502了是吧,我就因为这个折腾好久
仔细看命令执行完的输出里面有一句Bind() …. permission denied之类的.
是因为--uid www-data --gid www-data用了www-data用户和组,
解决办法

1. 切换到/目录,用ls -al看看你的文件的权限
   出现这个问题应该是/mysite/这个文件夹对www-data用户没有开放写的权限
   先用sudo chgrp -R www-data /mysite来改下这个文件夹的组,
   再用sudo chmod 775 /mysite这里没有-R参数咯,开启www-data对这个文件夹写的权限
   以后也是,发现需要权限的就用这个方法来逐步放开,不要图省事一次全部放开777权限,这样不安全

Make uWSGI startup when the system boots

The last step is to make it all happen automatically at system startup time.

For many systems, the easiest (if not the best) way to do this is to use the rc.local file.

Edit /etc/rc.local and add:

/usr/local/bin/uwsgi --emperor /etc/uwsgi/vassals --uid www-data --gid www-data --daemonize /var/log/uwsgi-emperor.log

before the line “exit 0”.

And that should be it!

Further configuration

It is important to understand that this has been a tutorial, to get you started. You do need to read the nginx and uWSGI documentation, and study the options available before deployment in a production environment.

Both nginx and uWSGI benefit from friendly communities, who are able to offer invaluable advice about configuration and usage.

nginx

General configuration of nginx is not within the scope of this tutorial though you’ll probably want it to listen on port 80, not 8000, for a production website.

You should also configure a separate nginx location block for serving non-Django files. For example, it’s inefficient to serve static files via uWSGI. Instead, serve them directly from Nginx and completely bypass uWSGI.

uWSGI

uWSGI supports multiple ways to configure it. See uWSGI’s documentation and examples.

Some uWSGI options have been mentioned in this tutorial; others you ought to look at for a deployment in production include (listed here with example settings):

env = DJANGO_SETTINGS_MODULE=mysite.settings # set an environment variable
safe-pidfile = /tmp/project-master.pid # create a pidfile
harakiri = 20 # respawn processes taking more than 20 seconds
limit-as = 128 # limit the project to 128 MB
max-requests = 5000 # respawn processes after serving 5000 requests
daemonize = /var/log/uwsgi/yourproject.log # background the process & log