How to Install Apache on Ubuntu Linux

How to use Apache HTTP server on Ubuntu Linux

Installing Apache on Ubuntu Linux is straightforward because the Apache HTTP server is ready to go in Ubuntu’s software sources, letting you use the simple apt package manager to get it running.

Apache is available in Ubuntu repositories, so we can easily install it using the apt package management tool.

To install Apache, run the commands below:

sudo apt update
sudo apt install apache2

The commands above will install the Apache HTTP server.

To find out if Apache is installed and running, use the status check command below.

sudo systemctl status apache2

The command will output similar lines below when Apache is running.

apache2.service - The Apache HTTP Server
     Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2021-09-15 12:29:40 CDT; 10s ago
       Docs: https://httpd.apache.org/docs/2.4/
    Process: 4860 ExecStart=/usr/sbin/apachectl start (code=exited, status=0/SUCCESS)
   Main PID: 4864 (apache2)
      Tasks: 55 (limit: 4651)
     Memory: 4.7M
     CGroup: /system.slice/apache2.service
             ├─4864 /usr/sbin/apache2 -k start
             ├─4865 /usr/sbin/apache2 -k start
             └─4866 /usr/sbin/apache2 -k start

Sep 15 12:29:40 ubuntu2004 systemd[1]: Starting The Apache HTTP Server...
Sep 15 12:29:40 ubuntu2004 apachectl[4863]: AH00558: apache2: Could not reliably determine the >

How to allow Apache through the Ubuntu firewall

If your Ubuntu server’s firewall is on, you’ll need to let Apache’s web traffic pass through by opening up ports 80 for regular web pages (HTTP) and 443 for secure pages (HTTPS).

If you’re using UFW to manage the Ubuntu firewall, run the below commands to allow traffic.

sudo ufw allow 'Apache Full'

That will allow full traffic to Apache.

Browse the server hostname or IP address with the firewall opened to see if the Apache default page is up.

http://localhost

You should see the Apache default welcome page.

How to configure Apache on Ubuntu Linux

After you install Apache on Ubuntu, you’ll find all its main settings and folders inside the /etc/apache2 directory, which is like the server’s main home.

On Ubuntu Linux, these are Apache directory structures and configuration files.

All Apache configuration files are located in the /etc/apache2 directory. This is considered the Apache home directory.

Apache’s main configuration file is /etc/apache2/apache2.conf. Global configuration settings are done in the file, but this file is rarely ever touched.

Port configurations, including changing the default listen ports, are specified in this file /etc/apache2/ports.conf. The ports in here are what Apache listens to for traffic.

Apache Virtual Host files use the `/etc/apache2/sites-available` directory for website definitions. Apache only uses these definitions after activation. Activated configurations link to the `/etc/apache2/sites-enabled` directory.

sudo a2ensite example.com.conf

The command above will create a symlink of the website configuration files found in the sites-available directory to the sites-enabled directory.

sudo a2dissite example.com.conf

Apache uses modules to enhance and add additional functionalities located in the /etc/apache2/mods-available/ directory.

Modules are only available to load with Apache when enabled and symlinked to the /etc/apache2/mods-enable/ directory.

Apache modules activate or deactivate with `a2enconf` and `a2disconf` commands. After turning on Apache modules and linking them to the `mod-enable` directory, the Apache web server loads the selected modules.

Apache log files, specifically `access.log` and `error.log`, store server activity and issues within the `/var/log/apache/` folder on Ubuntu Linux. These two files allow users to understand server operations and identify problems.

Apache's Ubuntu configuration files store advanced web server settings. Future guides will explain these extra Apache settings, demonstrating practical uses of the web server's full power.

Conclusion:

This guide explained how to install and use the Apache web server on Ubuntu Linux. Readers can report errors or add information using the comment form provided below the guide.