How to Install Apache Web Server on Ubuntu 18.04


The Apache HTTP server is the most widely-used web server in the world. It provides many powerful features including dynamically loadable modules, robust media support, and extensive integration with other popular software.

In this tutorial, you'll learn how to install an Apache web server on your Ubuntu 18.04 server.


Prerequisites
Before you begin this guide, you should have a regular, non-root user with sudo privileges configured on your server. Additionally, you will need to enable a basic firewall to block non-essential ports. You can learn how to configure a regular user account and set up a firewall for your server by following our basic server setup guide for Ubuntu 18.04.

When you have an account available, log in as your non-root user to begin.


Installing Apache
Apache is available within Ubuntu's default software repositories, making it possible to install it using conventional package management tools.

Let's begin by updating the local package index to reflect the latest upstream changes:

sudo apt update

Then, install the apache2 package:

sudo apt install apache2

After confirming the installation, apt will install Apache and all required dependencies.


Adjusting the Firewall
Before testing Apache, it's necessary to modify the firewall settings to allow outside access to the default web ports. Assuming that you followed the instructions in the prerequisites, you should have a UFW firewall configured to restrict access to your server.

During installation, Apache registers itself with UFW to provide a few application profiles that can be used to enable or disable access to Apache through the firewall.

List the ufw application profiles by typing:

sudo ufw app list

You will see a list of the application profiles:

Output
Available applications:
  Apache
  Apache Full
  Apache Secure
  OpenSSH

As you can see, there are three profiles available for Apache:

Apache: This profile opens only port 80 (normal, unencrypted web traffic)
Apache Full: This profile opens both port 80 (normal, unencrypted web traffic) and port 443 (TLS/SSL encrypted traffic)
Apache Secure: This profile opens only port 443 (TLS/SSL encrypted traffic)

It is recommended that you enable the most restrictive profile that will still allow the traffic you've configured. Since we haven't configured SSL for our server yet in this guide, we will only need to allow traffic on port 80:

sudo ufw allow 'Apache'

You can verify the change by typing:

sudo ufw status

You should see HTTP traffic allowed in the displayed output:

Output
Status: active

To                         Action      From
--                         ------      ----
OpenSSH                    ALLOW       Anywhere                 
Apache                     ALLOW       Anywhere                 
OpenSSH (v6)               ALLOW       Anywhere (v6)            
Apache (v6)                ALLOW       Anywhere (v6)

As you can see, the profile has been activated to allow access to the web server.


Checking your Web Server
At the end of the installation process, Ubuntu 18.04 starts Apache. The web server should already be up and running.

Check with the systemd init system to make sure the service is running by typing:

sudo systemctl status apache2

Output
● apache2.service - The Apache HTTP Server
   Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
  Drop-In: /lib/systemd/system/apache2.service.d
           └─apache2-systemd.conf
   Active: active (running) since Tue 2018-04-24 20:14:39 UTC; 9min ago
 Main PID: 2583 (apache2)
    Tasks: 55 (limit: 1153)
   CGroup: /system.slice/apache2.service
           ├─2583 /usr/sbin/apache2 -k start
           ├─2585 /usr/sbin/apache2 -k start
           └─2586 /usr/sbin/apache2 -k start

As you can see from this output, the service appears to have started successfully. However, the best way to test this is to request a page from Apache.

You can access the default Apache landing page to confirm that the software is running properly through your IP address. If you do not know your server's IP address, you can get it a few different ways from the command line.

Try typing this at your server's command prompt:

hostname -I

You will get back a few addresses separated by spaces. You can try each in your web browser to see if they work.

An alternative is typing this, which should give you your public IP address as seen from another location on the internet:

curl -4 icanhazip.com

When you have your server's IP address, enter it into your browser's address bar:

http://your_server_ip

You should see the default Ubuntu 18.04 Apache web page:


This page indicates that Apache is working correctly. It also includes some basic information about important Apache files and directory locations.


Managing the Apache Process
Now that you have your web server up and running, let's go over some basic management commands.

To stop your web server, type:

sudo systemctl stop apache2

To start the web server when it is stopped, type:

sudo systemctl start apache2

To stop and then start the service again, type:

sudo systemctl restart apache2

If you are simply making configuration changes, Apache can often reload without dropping connections. To do this, use this command:

sudo systemctl reload apache2

By default, Apache is configured to start automatically when the server boots. If this is not what you want, disable this behavior by typing:

sudo systemctl disable apache2

To re-enable the service to start up at boot, type:

sudo systemctl enable apache2

Apache should now start automatically when the server boots again.


Setting Up Virtual Hosts (Recommended)
When using the Apache web server, you can use virtual hosts (similar to server blocks in Nginx) to encapsulate configuration details and host more than one domain from a single server. We will set up a domain called example.com, but you should replace this with your own domain name.

Apache on Ubuntu 18.04 has one server block enabled by default that is configured to serve documents from the /var/www/html directory. While this works well for a single site, it can become unwieldy if you are hosting multiple sites. Instead of modifying /var/www/html, let's create a directory structure within /var/www for our example.com site, leaving /var/www/html in place as the default directory to be served if a client request doesn't match any other sites.

Create the directory for example.com as follows, using the -p flag to create any necessary parent directories:

sudo mkdir -p /var/www/example.com/html

Next, assign ownership of the directory with the $USER environmental variable:

sudo chown -R $USER:$USER /var/www/example.com/html

The permissions of your web roots should be correct if you haven't modified your unmask value, but you can make sure by typing:

sudo chmod -R 755 /var/www/example.com

Next, create a sample index.html page using nano or your favorite editor:

nano /var/www/example.com/html/index.html

Inside, add the following sample HTML:

<html>
    <head>
        <title>Welcome to Example.com!</title>
    </head>
    <body>
        <h1>Success!  The example.com server block is working!</h1>
    </body>
</html>

Save and close the file when you are finished.

In order for Apache to serve this content, it's necessary to create a virtual host file with the correct directives. Instead of modifying the default configuration file located at /etc/apache2/sites-available/000-default.conf directly, let's make a new one at /etc/apache2/sites-available/example.com.conf:

sudo nano /etc/apache2/sites-available/example.com.conf

Paste in the following configuration block, which is similar to the default, but updated for our new directory and domain name:

<VirtualHost *:80>
    ServerAdmin admin@example.com
    ServerName example.com
    ServerAlias www.example.com
    DocumentRoot /var/www/example.com/html
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

Notice that we've updated the DocumentRoot to our new directory and ServerAdmin to an email that the example.com site administrator can access. We've also added two directives: ServerName, which establishes the base domain that should match for this virtual host definition, and ServerAlias, which defines further names that should match as if they were the base name.

Save and close the file when you are finished.

Let's enable the file with the a2ensite tool:

sudo a2ensite example.com.conf

Disable the default site defined in 000-default.conf:

sudo a2dissite 000-default.conf

Next, let's test for configuration errors:

sudo apache2ctl configtest

You should see the following output:

Output
Syntax OK

Restart Apache to implement your changes:

sudo systemctl restart apache2

Apache should now be serving your domain name. You can test this by navigating to http://example.com, where you should see something like this:



Wrapping up
Now that you have your apache web server installed, you have many options for the type of content you can serve and the technologies you can use to create a richer experience.

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