Nginx Configuration

We will use Ubuntu as an example to install Nginx and set up basic configurations.

For other operating systems, please refer to the official documentation or other resources for installation.

Installing Nginx

First, update the software repository and install Nginx:

sudo apt update
sudo apt install -y nginx

Once installed, the Nginx service will start automatically.

We can check if Nginx is running properly using systemctl:

sudo systemctl status nginx

If it shows active (running), it means Nginx has started successfully.

warning

If the server has a firewall enabled (such as UFW), ensure that HTTP and HTTPS traffic are allowed:

sudo ufw allow 'Nginx Full'

Nginx Configuration

Main File

The main configuration file for Nginx is /etc/nginx/nginx.conf.

For detailed usage, please refer to our supplementary documentation: nginx.conf

tip

Due to space constraints, the detailed explanation is provided separately. Be sure to check it out. ⬆ ⬆ ⬆

Site Files

For each website or service, we typically configure them in two directories:

• /etc/nginx/sites-available/: Create individual configuration files.
• /etc/nginx/sites-enabled/: Enable sites through symbolic links.

Nginx uses the sites-available and sites-enabled directories to manage configurations for multiple sites.

For detailed usage, please refer to our supplementary documentation: sites-available/default

tip

Again, make sure to check out the explanation file. ⬆ ⬆ ⬆

Testing and Verification

After completing the configuration, it's essential to verify if the setup is correct:

1. Check Nginx Configuration Syntax

   sudo nginx -t

   If it shows syntax is ok and test is successful, the configuration is correct.

2. Reload Nginx to Apply New Configuration

   sudo systemctl reload nginx

3. Verify the Service

   Use a browser or curl to access http://temp_api.example.com/test and check if the expected response is received.

tip

Please note that the http://temp_api.example.com/test endpoint is based on the hypothetical API endpoint from the previous section.

You should modify the server_name and proxy_pass settings in the configuration file according to your actual setup.

info

Common Commands

# Start Nginx
sudo systemctl start nginx

# Stop Nginx
sudo systemctl stop nginx

# Restart Nginx (typically used for major configuration changes)
sudo systemctl restart nginx

# Reload Nginx (recommended for minor configuration changes)
sudo systemctl reload nginx

Multi-Site Configuration

Nginx uses server blocks to define virtual hosts, and it determines which site to process based on the requested Host and listen port. When a user sends an HTTP request, Nginx first compares the requested "Host" and "Port" with the configured server blocks and processes the matching one.

Typically, each site is configured to listen on a specified port (like 80 or 443) with the listen directive, and the server_name directive is used to match a specific domain. For example, example.com and api.example.com can each have their own server_name, and Nginx will select the appropriate configuration based on the Host header.

Here’s an example of a typical multi-site configuration:

/etc/nginx/sites-available/example.com

server {
    listen 80;
    server_name example.com;
    root /var/www/example.com;
    index index.html;
}

server {
    listen 80;
    server_name api.example.com;
    location / {
        proxy_pass http://localhost:5000/;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

• The first server block handles static resources for example.com.
• The second server block handles requests for api.example.com and proxies them to the local API service running on port 5000.

For example, when users access http://example.com, Nginx will route the request to the index.html file in /var/www/example.com; when they access http://api.example.com, the request will be forwarded to the API service on port 5000.

Default Configuration

We can set up a default_server in the configuration file, so when there is no matching server_name, Nginx will use the default server to handle the request:

server {
    listen 80 default_server;
    server_name _;
    return 404;
}

This configuration prevents requests with unspecified domain names from being routed to the wrong site.

Troubleshooting

Finally, let's take a look at how to troubleshoot when issues arise.

1. Check Nginx Configuration for Errors

   sudo nginx -t

   If there are error messages, follow the instructions to fix the configuration.

2. Check Nginx Service Status

   sudo systemctl status nginx

   If it shows active (running), Nginx is running normally; if it shows failed, check the error logs.

3. View Error Logs

   sudo journalctl -u nginx --no-pager --lines=30

   Or directly view the error.log:

   sudo tail -f /var/log/nginx/error.log

   These logs help identify specific errors like 404, 502, 403, etc.

Conclusion

In this chapter, we covered how to install Nginx on Ubuntu and configure basic sites, reverse proxy, and multi-site management.

We also learned how to test and verify configurations to ensure the website is functioning correctly. With these basic settings, Nginx can meet the needs of most static websites and API proxies.

In the next chapter, we’ll look at how to configure HTTPS and use Let's Encrypt.