Nginx with fcgiwrap on Ubuntu 20.04

2020-06-14 System @JS

Requirements: user with root privileges or non-root user with sudo privileges.

Nginx installation

$ sudo apt update && sudo apt upgrade -y
$ sudo apt install nginx -y
$ sudo systemctl is-enabled nginx.service
$ sudo systemctl status nginx.service
## if nginx is not enabled, enable it and run ##

Important details for Nginx configuration:

default HTTP port => 80
default HTTPS port => 443
user and group for Nginx server => www-data
Nginx DocumentRoot => /var/www/html/
Nginx config directory => /etc/nginx/
global config file => /etc/nginx/nginx.conf
virtual domain/host config directory => /etc/nginx/sites-available/
currently enabled domain/host config directory => /etc/nginx/sites-enabled/
various config options => /etc/nginx/snippets/
server log file => /var/log/nginx/access.log
server error log file => /var/log/nginx/error.log

Configuring Nginx virtual hosts

Create a config file for your domain. In my case for test domain ctx06vm.local.lnxorg:

$ sudo vi /etc/nginx/sites-available/ctx06vm-local-lnxorg.conf

server {
	listen 80;
	listen [::]:80;
 
	server_name ctx06vm.local.lnxorg;
 
	root /home/ctx06vm-local-lnxorg/html;
	index index.html;
        access_log  /var/log/nginx/ctx06vm_local_lnxorg_access.log;
        error_log  /var/log/nginx/ctx06vm_local_lnxorg_error.log;
 
	location / {
		try_files $uri $uri/ =404;
	}
}

Create a new user for your domain. An example for my case:

$ sudo useradd -d /home/ctx06vm-local-lnxorg -m -k /dev/null -s /usr/sbin/nologin pageadmin

Make sure we lock the Linux user account:

$ sudo passwd -l pageadmin

Create html folder with *.html files and set permission using the chown command:

## for my case: ##
$ sudo mkdir -pv /home/ctx06vm-local-lnxorg/html/
$ sudo chown -R pageadmin: /home/ctx06vm-local-lnxorg/

Turn on created virtual domain, test Nginx virtual host config and reload nginx service:

## for my case:
$ sudo ln -v -s /etc/nginx/sites-available/ctx06vm-local-lnxorg.conf /etc/nginx/sites-enabled/
$ sudo nginx -t
$ sudo systemctl reload nginx.service

Firewall configuration

$ sudo ufw allow 80/tcp comment 'accept HTTP Nginx connections'
$ sudo ufw allow 443/tcp comment 'accept HTTPS/TLS Nginx connections'
$ sudo ufw status

fcgiwrap installation and configuration

$ sudo apt install fcgiwrap
$ sudo systemctl status fcgiwrap.service
## if fcgiwrap is not enabled, enable it and run

Create a new configuration for fcgiwrap in /etc/nginx/fcgiwrap.conf. Example configuration:

location /cgi-bin/ {
  gzip off;
  root  /usr/lib;
  fastcgi_pass  unix:/var/run/fcgiwrap.socket;
  include /etc/nginx/fastcgi_params;
  fastcgi_param SCRIPT_FILENAME  /usr/lib$fastcgi_script_name;
}

Edit your Nginx virtual host config file. Locate the server section and add the following directive:

[...]
        include /etc/nginx/fcgiwrap.conf;
[...]

Test Nginx virtual host config and reload nginx service:

$ sudo nginx -t
$ sudo systemctl reload nginx.service

Create a cgi-bin directory under /usr/lib/:

$ sudo mkdir -vp /usr/lib/cgi-bin/

Writing Hello World CGI script

Create the /usr/lib/cgi-bin/hello.cgi file with the following code:

#!/usr/bin/env bash
echo "Content-type: text/html"
echo ""
now="$(date)"
echo '<html><head><title>Hello World - CGI app</title></head>'
echo '<body>'
echo '<h2>Hello World!</h2>'
echo "The current date and time : ${now}<br/>"
echo '</body>'
echo '</html>'

Set execute permissions for this file:

$ sudo chmod +x -v /usr/lib/cgi-bin/hello.cgi

Test it. Open a web-browser and type url: https://your-domain/cgi-bin/hello.cgi.