NGINX as Webserver

New to NGINX? Start by reading NGINX introduction.

Notes

• webserver is something that serves static contents (HTML, media, etc.)

• NGINX was primarily introduced as a webserver

• NGINX can server from different locations and in different ports at the same time

• default site is at /etc/nginx/site-available/default but inferring from the previous point, we can add multiple site configuration files at /etc/nginx/sites-available each serving on different ports or even different domains such as:

  /etc/nginx/sites-available/
  ├── default
  ├── example.com
  └── mysite.com

• /etc/nginx/sites-available just makes site available but not ready to serve, for the site be ready to serve, there should be symlink at /etc/nginx/sites-enabled of each site which is ready to serve content:

  sudo ln -s /etc/nginx/sites-available/mysite.com /etc/nginx/sites-enabled/

  which will create a symblink as such:

  lrwxrwxrwx 1 root root 37 Oct  7 11:52 /etc/nginx/sites-enabled/mysite.com -> /etc/nginx/sites-available/mysite.com

  Why Symlink?

  • changes made to /etc/nginx/sites-available/mysite.com are directly reflected on /etc/nginx/sites-enabled/mysite.com
  • symlink is just a pointer which means it saves storage

• generally in production, there will mostly be only one webserver with a single domain but multi server architecture helps easy develop and test sites/apps

Serving Static Content

1. The general flow is by start adding config file at /etc/nginx/sites-available/ and enabling by symlink at /etc/nginx/sites-enabled/ when ready. So, first:

   sudo mkdir /etc/nginx/sites-available/mysite.com

2. The most basic skeleton to write configuration for NGINX webserver is:

   http {
       server {
           location / {
   
           }
       }
   }

   However http block can be omitted and just server {} is fine too.

3. Add simple root directive to location block directive:

   location / {
       root /data/www;
   }

   When requests comes at mysite.com/ or mysite.com, serve from /data/www.

4. This means data/www should exist and the default HTML file i.e. index.html file should exist there to start serving at /:

   sudo mkdir -p /data/www/
   echo "HI from mysite.com" | sudo tee /data/www/mysite.com
   sudo chown -R www-data:www-data /data/www/

   Changing owner is not mandatory (because NGINX is started as sudo nginx) but a good pratice because generally NGINX user and group is www-data and not root.

5. Add more location directive if necessary, for example to serve /images from another location such as /media/images/:

   location /images/ {
       root /media/images/;
   }

   When requests comes at mysite.com/images/picture.png, return the image from /media/images/picture.png if available.

6. Specify listening address:port inside the server block (generally the first line). This is necessary because default site is already using default port 80:

   http {
       server {
           listen 8090;
           ...
       }
   }

   Here address part is omitted so universal address 0.0.0.0 is applied.

7. [Optional] Seperating access.log and error.log for this site only is also a good idea:

   http {
       server {
           ...
           access_log /var/log/nginx/mysite.com/access.log;
           error_log /var/log/nginx/mysite.com/error.log;
       }
   }

   These file should exist before nginx is started, so the same idea goes here:

   sudo mkdir /var/log/nginx/mysite.com/
   sudo touch /var/log/nginx/mysite.com/{access,error}.log
   sudo chown -R www-data:adm /var/log/nginx/mysite.com/

   Why www-data:adm? Because it is common practice for log files.

8. Create symlink of mysite.com in /etc/nginx/sites-enabled:

   sudo ln -s /etc/nginx/sites-available/mysite.com /etc/nginx/sites-enabled/

9. Validate and start serving:

   sudo nginx -t && sudo nginx

10. Access your site:

    curl localhost:8090

    should return:

    HI from mysite.com

    Because the site is accessed, now /var/log/nginx/mysite.com/access.log does have some access logs, see it yourself.

Important Notes

• naming mysite.com doesn’t mean NGINX server is allowed to serve as mysite.com
• if you want to serve as mysite.com publicly, you should own the domain in order to serve as mysite.com becuase you need to set A or CNAME DNS records (from the domain name provider console such as: cloudflare or godaddy) to map mysite.com to your public IP address
• continuing to previous point, you should also set server_name directive as mysite.com inside server {} block -> this only solves serving as http://mysite.com
• to serve HTTPS, you need to have TLS certificate which is signed by trusted CA and mention it in NGINX configuration (ssl directive)