Hosting multiple Websites on a single Nginx Server

Running multiple websites on a single server is a common requirement for web developers and system administrators. This guide will walk you through the process of configuring Nginx to serve multiple websites with separate domains, each running their own Python/Django application using Gunicorn.
In this article am assuming you know how to deploy and setup the user and permisions.
Directory Structure
Your projects should be organized in a clean directory structure:

/home/username/
├── FirstProject/
│   ├── manage.py
│   └── ... (other Django files)
├── SecondProject/
│   ├── manage.py
│   └── ... (other Django files)
└── venv/

Step 1: Configure Nginx Virtual Hosts
Nginx uses server blocks (virtual hosts) to handle multiple domains. Create separate configuration files for each website:

Create the first website's configuration:

server {
    listen 80;
    server_name your-first-domain.com;

    location = /favicon.ico { 
        access_log off; 
        log_not_found off; 
    }

    location /static/ {
        root /home/username/FirstProject;
    }

    location / {
        include proxy_params;
        proxy_pass http://unix:/run/gunicorn.sock;
    }
}

Create the second website's configuration:

server {
    listen 80;
    server_name your-second-domain.com;

    location = /favicon.ico {
        access_log off;
        log_not_found off;
    }

    location /static/ {
        root /home/username/SecondProject;
    }

    location / {
        include proxy_params;
        proxy_pass http://unix:/run/gunicorn-second.sock;
    }
}

Step 2: Set Up Gunicorn Services
Each website needs its own Gunicorn service and socket. Here's how to set them up:

Create the first Gunicorn service file (/etc/systemd/system/gunicorn.service):

[Unit]
Description=gunicorn daemon for first site
Requires=gunicorn.socket
After=network.target

[Service]
User=username
Group=www-data
WorkingDirectory=/home/username/FirstProject
ExecStart=/home/username/venv/bin/gunicorn \
    --access-logfile - \
    --workers 3 \
    --bind unix:/run/gunicorn.sock \
    FirstProject.wsgi:application

[Install]
WantedBy=multi-user.target

Create the second Gunicorn service file (/etc/systemd/system/gunicorn-second.service):

[Unit]
Description=gunicorn daemon for second site
Requires=gunicorn-second.socket
After=network.target

[Service]
User=username
Group=www-data
WorkingDirectory=/home/username/SecondProject
ExecStart=/home/username/venv/bin/gunicorn \
    --access-logfile - \
    --workers 3 \
    --bind unix:/run/gunicorn-second.sock \
    SecondProject.wsgi:application

[Install]
WantedBy=multi-user.target

Create socket files for both services:

First socket (/etc/systemd/system/gunicorn.socket):

Description=gunicorn socket for first site

[Socket]
ListenStream=/run/gunicorn.sock
User=www-data

[Install]
WantedBy=sockets.target

Second socket (/etc/systemd/system/gunicorn-second.socket):

[Unit]
Description=gunicorn socket for second site

[Socket]
ListenStream=/run/gunicorn-second.sock
User=www-data

[Install]
WantedBy=sockets.target

Step 3: Start and Enable Services

Reload systemd to recognize new services:
sudo systemctl daemon-reload
Start and enable both sockets:
sudo systemctl start gunicorn.socket gunicorn-second.socket
sudo systemctl enable gunicorn.socket gunicorn-second.socket
Start and enable both services:
sudo systemctl start gunicorn gunicorn-second
sudo systemctl enable gunicorn gunicorn-second
Test Nginx configuration:
sudo nginx -t
Reload and check service status

sudo systemctl reload nginx
sudo systemctl status gunicorn
sudo systemctl status gunicorn-second

and wallah