我不明白nginx如何在我的设置中找到gunicorn

Question

很大程度上遵循https://tutos.readthedocs.io/en/latest/source/ndg.html的说明，我运行了一个nginx-gunicorn-django堆栈，它已经可靠运行了几个星期了。在查看如何添加内容（用户上传的媒体文件）时，我查看了我的nginx配置，看起来我没有编辑过任何提及gunicorn的内容。在进行任何更复杂的更改之前，我想了解发生了什么。当nginx配置目录树中没有提到gunicorn时，nginx如何将请求转发给gunicorn？

我的主要nginx配置文件如下所示，我认为这是安装的默认设置：

user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
        worker_connections 768;
        # multi_accept on;
}

http {

        sendfile on;
        tcp_nopush on;
        tcp_nodelay on;
        keepalive_timeout 65;
        types_hash_max_size 2048;
        # server_tokens off;

        # server_names_hash_bucket_size 64;
        # server_name_in_redirect off;

        include /etc/nginx/mime.types;
        default_type application/octet-stream;

        ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
        ssl_prefer_server_ciphers on;

        access_log /var/log/nginx/access.log;
        error_log /var/log/nginx/error.log;

        gzip on;
        gzip_disable "msie6";

        include /etc/nginx/conf.d/*.conf;
        include /etc/nginx/sites-enabled/*;
}

我的gunicorn启动脚本是：

#!/bin/bash

# Based on an example from https://tutos.readthedocs.io/en/latest/source/ndg.html

NAME="makers"                              # Name of the application (*)
DJANGODIR=/var/www/makers                  # Django project directory (*)
SOCKFILE=/var/www/makers/run/gunicorn.sock # we will communicate using this unix socket (*)
USER=nginx                                 # the user to run as (*)
GROUP=webdata                              # the group to run as (*)
NUM_WORKERS=1                              # how many worker processes should Gunicorn spawn (*)
DJANGO_SETTINGS_MODULE=makers.settings     # which settings file should Django use (*)
DJANGO_WSGI_MODULE=makers.wsgi             # WSGI module name (*)

echo "Starting $NAME as `whoami`"

# Activate the virtual environment
cd $DJANGODIR
source /var/www/makers_venv/bin/activate
export DJANGO_SETTINGS_MODULE=$DJANGO_SETTINGS_MODULE
export PYTHONPATH=$DJANGODIR:$PYTHONPATH

# Create the run directory if it doesn't exist
RUNDIR=$(dirname $SOCKFILE)
test -d $RUNDIR || mkdir -p $RUNDIR

# Start your Django Unicorn
# Programs meant to be run under supervisor should not daemonize themselves (do not use --daemon)
exec /var/www/makers_venv/bin/gunicorn ${DJANGO_WSGI_MODULE}:application \
  --name $NAME \
  --workers $NUM_WORKERS \
  --user $USER \
  --bind 0.0.0.0:8000
#   --bind=unix:$SOCKFILE

Answer 1

nginx如何将请求传递给WSGI服务器（即gunicorn）在location块中的一个server指令中定义，该指令包含在http块中，您可以在/etc/nginx.conf文件中看到：

http {

  # other http settings
  .....

  include /etc/nginx/conf.d/*.conf;
  include /etc/nginx/sites-enabled/*;
}

在定义server的文件中，在所有server和location指令中，您可能会看到如下设置：

server {

  ...

  location / {

      ...

      # if your guincorn is listening to an IP add
      proxy_pass http:127.0.0.1:8000
      # or if your gunicorn is listening to a unix socket
      # proxy_pass http://unix:/var/www/makers/run/gunicorn.sock 
  }

根据你的gunicorn启动脚本，你的nginx通过端口8000的IP地址将请求传递给gunicorn：

exec /var/www/makers_venv/bin/gunicorn makers.wsgi:application --bind 0.0.0.0:8000

我建议你阅读Understanding the Nginx Configuration File Structure and Configuration Contexts，或者我的blog，以便更好地了解nginx和gunicorn（或一般的WSGI）是如何工作的。