Install Apache In Ubuntu

Step 1: Install Apache and Allow in Firewall

For our purposes, we can get started by typing these commands:

sudo apt-get update

sudo apt-get install apache2

Step 2: Set Global ServerName to Suppress Syntax Warnings

Next, we will add a single line to the /etc/apache2/apache2.conf file to suppress a warning message. While harmless, if you do not set ServerName globally, you will receive the following warning when checking your Apache configuration for syntax errors:

sudo apache2ctl configtest

Output

AH00558: apache2: Could not reliably determine the server's fully qualified domain name, 

using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message 

Syntax OK

Open up the main configuration file with your text edit:

sudo nano /etc/apache2/apache2.conf

Add below line or Find ServerName and uncomment it 

ServerName server_domain_or_IP

Save and close the file when you are finished.
Next, check for syntax errors by typing:

sudo apache2ctl configtest

Output

Syntax OK