====== Install Nginx Webserver on Linux Ubuntu Server 20.04 LTS (Changing from Apache2 already installed) ======

It would be necessary to switch from Apache to Nginx if, for example, you want to install NextCloud and OnlyOffice Document Server on the same Ubuntu server and integrate them to work together in order to provide document creation, editing, collaboration, and cloud storage. A prerequisite for OnlyOffice Document Server is that it must run on Nginx webserver.  NextCloud can run on either Apache or Nginx, but Nginx is the common denominator to run both NextCloud and Only/Office Document Server on the same box.

<code>sudo apt update
sudo apt upgrade </code>

Stop apache2 if that webserver is also installed and running. It may also be necessary to change the http Port bind to Apache2 before starting Nginx after it is installed.

<code>sudo systemctl stop apache2.service</code>

See below if you need to change http port 80 that is bind to Apache2.

===== Installing Nginx Server =====

<code>sudo apt install nginx</code>

After the installation is completed, start the Nginx service and enable it to launch every time at system boot.  Check the status of Nginx.

<code>
sudo systemctl start nginx

sudo systemctl enable nginx

sudo systemctl status nginx
</code>

==== NGinx Could not Bind to http port 80 because Apache is already Bind to that Port ====

<QUOTE>
Jun 10 02:33:16 xsvr nginx[77940]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)

Jun 10 02:33:16 xsvr nginx[77940]: nginx: [emerg] bind() to [::]:80 failed (98: Address already in use)

Jun 10 02:33:17 xsvr nginx[77940]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)

Jun 10 02:33:17 xsvr nginx[77940]: nginx: [emerg] bind() to [::]:80 failed (98: Address already in use)

Jun 10 02:33:17 xsvr nginx[77940]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)

Jun 10 02:33:17 xsvr nginx[77940]: nginx: [emerg] bind() to [::]:80 failed (98: Address already in use)

Jun 10 02:33:18 xsvr nginx[77940]: nginx: [emerg] still could not bind()
Jun 10 02:33:18 xsvr systemd[1]: nginx.service: Control process exited, code=exited, status=1/FAILURE

Jun 10 02:33:18 xsvr systemd[1]: nginx.service: Failed with result 'exit-code'.

Jun 10 02:33:18 xsvr systemd[1]: Failed to start A high performance web server and a reverse proxy server.</QUOTE>


==== Change Apache2 Default Port to Custom Port on Ubuntu / Debian ====

Change Apache port on Debian/Ubuntu. Edit /etc/apache2/ports.conf file, $ sudo vi /etc/apache2/ports.conf. Find the following line: Listen 80. ..

<code>sudo vim /etc/apache2/ports.conf</code>

Find the following line:

<code>Listen 80</code>

Change it to a random port of you choice, for example 8090.

<code>Listen 8090 </code>

This entry make the server to accept connections on port 8090 on all interfaces. To make the server accept connections on port 8090 for a specific interface, just include the corresponding network interface’s IP address as shown below.

<code>Listen 192.168.1.101:8090</code>

This will be helpful if your server has multiple IP addresses or network interfaces.

Save and close the file.

If the ports.conf file also has the following, may need to change ssl port 443 to port 444 or something else.

<code>
<IfModule ssl_module>
        Listen 443
</IfModule>

<IfModule mod_gnutls.c>
        Listen 443
</IfModule>
</code>


Additionally, in Ubuntu and Debian, you also have to change the port number in /etc/apache2/sites-enabled/000-default.conf file too.

<code>
$ sudo vi /etc/apache2/sites-enabled/000-default.conf

</code>

Find the following line and change the port number.

<code><VirtualHost *:8090></code>

Save and close the file.

Then, restart Apache service to take effect the changes.

<code>$ sudo systemctl restart apache2</code>

Now let us verify the port settings:

<code>$ sudo netstat -tulpn | grep :8090</code>

Sample Output:

<code>tcp6     0       0:::880         :::*    LISTEN      4066/apache2 </code>

==== Return (above) to Start Nginx, Enable it to start at start-up, and check its status ====

<code>
sudo systemctl start nginx

sudo systemctl enable nginx

sudo systemctl status nginx
</code>

===== Open the UFW firewall for Nginx port 80 and 443 =====

If you have enabled the uncomplicated firewall (ufw) on Ubuntu, then you will need to type the following ufw command to open TCP port number 80 and 443 for everyone.  If the firewall is not enabled because you are behind a NAT router (or whatever reason), then skip these steps to open ports in the firewall.

<code>
sudo ufw allow 80/tcp comment 'accept HTTP Nginx'

sudo ufw allow 443/tcp comment 'accept HTTPS/TLS Nginx connections'
</code>

Verify port status it:

<code>sudo ufw status</code>

===== Configure Nginx to Use the PHP Processor =====

===== Configure PhpMyAdmin within Nginx Server default sites-available virtual host file =====

Now go to the '/etc/nginx' configuration directory, and edit the default virtual host file.

<code>
cd /etc/nginx/sites-available/

sudo cp default default-original 

sudo vim default
</code>

Paste the following Nginx configuration for PHPMyAdmin inside the 'server {...}' bracket.

<code>
location /phpmyadmin {
    root /usr/share/;
    index index.php;
    try_files $uri $uri/ =404;

location ~ ^/phpmyadmin/(doc|sql|setup)/ {
    deny all;
    }

location ~ /phpmyadmin/(.+\.php)$ {
    fastcgi_pass unix:/run/php/php7.4-fpm.sock;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include fastcgi_params;
    include snippets/fastcgi-php.conf;
    }
}
</code>

Save and exit.

Test the nginx configuration and make sure there is no error, then restart the nginx service.

<code>
sudo nginx -t

sudo systemctl reload nginx
</code>

And we've added the Nginx configuration for our phpMyAdmin installation, it's accessible through the path URL as 'http://server-ip/phpmyadmin'.