Introduction
The Apache web server is the most popular way of serving web content on the internet. It accounts for more than half of all active websites on the internet and is extremely powerful and flexible.
Apache breaks its functionality and components into individual units you can customize independently. The basic unit that describes an individual site or domain is called a virtual host.
Using virtual hosts, you can use one server to host multiple domains or sites off of a single interface or IP by using a matching mechanism. You configure a request for a domain to direct the visitor to a specific directory holding that site's information. In other words, you can host more than one web site on a single server. This scheme is expandable without any software limit as long as your server can handle the load.
In this tutorial, you'll set up two Apache virtual hosts on a Debian 8 server, serving different content to visitors based on the domain they visit.
Prerequisites
To complete this tutorial, you will need:
- A Debian 8 server with a non-root user with sudo privileges. You can set up a user with these privileges in our Initial Server Setup with Debian 8 guide.
- Apache installed and configured, as shown in How To Install Linux, Apache, MySQL, PHP (LAMP) Stack on Debian 8.
In this guide, we'll create virtual hosts for example.com and test.com, but you can substitute your own domains or values while following along. To point your domain names at your server, follow our tutorial How To Set Up a Host Name with DigitalOcean.
If you don't have domains available to play with, you can use example.com and test.com and follow Step 5 of this tutorial to configure your local hosts file to map those domains to your server's IP address. This will allow you to test your configuration from your local computer.
Step 1 — Creating the Directory Structure
The first step that we are going to take is to make a directory structure that will hold the site data that we will be serving to visitors.
Our document root, the top-level directory that Apache looks at to find content to serve, will be set to individual directories under the /var/www directory. We will create a directory for each of the virtual hosts we'll configure.
Within each of these directories, we'll create a folder called public_html that will hold the web pages we want to serve. This gives us a little more flexibility in how we deploy more complex web applications in the future; the public_html folder will hold web content we want to serve, and the parent folder can hold scripts or application code to support web content.
Create the directories using the following commands:
sudo mkdir -p /var/www/example.com/public_htmlsudo mkdir -p /var/www/test.com/public_html
Since we created the directories with sudo, they are owned by our root user. If we want our regular user to be able to modify files in our web directories, we change the ownership, like this:
sudo chown -R $USER:$USER /var/www/example.com/public_htmlsudo chown -R $USER:$USER /var/www/test.com/public_html
The $USER variable uses the value of the user you are currently logged in as when you press ENTER. By doing this, our regular user now owns the public_html subdirectories where we will be storing our content.
We should also modify our permissions a little bit to ensure that read access is permitted to the general web directory and all of the files and folders it contains so that pages can be served correctly. Execute this command to change the permissions on the /var/www folder and its children:
sudo chmod -R 755 /var/www
If you're new to managing permissions on Linux, see this tutorial.
Your web server should now have the permissions it needs to serve content, and your user should be able to create content within the necessary folders. Let's create an HTML file for each site.
We have our directory structure in place. Let's create some content to serve.
Step 2 — Creating Default Pages for Each Virtual Host
Let's create a simple index.html page for each site. This will help us ensure that our virtual hosts are configured properly later on.
Let's start with the page for example.com. Edit a new index.html file with the following command:
nano /var/www/example.com/public_html/index.html
In this file, create a simple HTML document that indicates that the visitor is looking at example.com's home page:
/var/www/example.com/public_html/index.html
<html>
<head>
<title>Welcome to Example.com!</title>
</head>
<body>
<h1>Success! The example.com virtual host is working!</h1>
</body>
</html>
Save and close the file when you are finished.
Now copy this file to the test.com site:
cp /var/www/example.com/public_html/index.html /var/www/test.com/public_html/index.html
Then open the file in your editor:
nano /var/www/test.com/public_html/index.html
Change the file so it references test.com instaed of example.com:
/var/www/test.com/public_html/index.html
<html>
<head>
<title>Welcome to Test.com!</title>
</head>
<body> <h1>Success! The test.com virtual host is working!</h1>
</body>
</html>
Save and close this file. You now have the pages necessary to test the virtual host configuration. Next, let's configure the virtual hosts.
Step 3 — Create New Virtual Host Files
Virtual host files specify the actual configuration of our virtual hosts and dictate how the Apache web server will respond to various domain requests.
Apache comes with a default virtual host file called 000-default.conf that you can use as a jumping off point. Copy this file for the first domain:
sudo cp /etc/apache2/sites-available/000-default.conf /etc/apache2/sites-available/example.com.conf
Note: The default Apache configuration in Debian 8 requires that each virtual host file end in .conf.
Open the new file in your editor:
sudo nano /etc/apache2/sites-available/example.com.conf
The file will look something like the following example, with some additional comments:
/etc/apache2/sites-available/example.com.conf
<VirtualHost *:80>
ServerAdmin webmaster@localhost
DocumentRoot /var/www/html
ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
This virtual host matches any requests that are made on port 80, the default HTTP port. Let's make a few changes to this configuration, and add a few new directives.
First, change the ServerAdmin directive to an email that the site administrator can receive emails through.
/etc/apache2/sites-available/example.com.conf
ServerAdmin [email protected]
Next, we need to add two new directives. The first, called ServerName, establishes the base domain for this virtual host definition. The second, called ServerAlias, defines further names that should match as if they were the base name. This is useful for matching additional hosts you defined, so both example.comand www.example.com both work, provided both of these hosts point to this server's IP address.
Add these two directives to your configuration file, right after the ServerAdmin line:
/etc/apache2/sites-available/example.com.conf
<VirtualHost *:80>
ServerAdmin webmaster@localhost
ServerName example.com
ServerAlias www.example.com
DocumentRoot /var/www/html
...
Next, change the location of the document root for this domain by altering the DocumentRoot directive to point to the directory you created for this host:
DocumentRoot /var/www/example.com/public_html
Once you've made these changes, your file should look like this:
/etc/apache2/sites-available/example.com.conf
<VirtualHost *:80>
ServerAdmin [email protected]
ServerName example.com
ServerAlias www.example.com
DocumentRoot /var/www/example.com/public_html
ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
Save and close the file.
Then create the second configuration file by creating a copy of this file:
sudo cp /etc/apache2/sites-available/example.com.conf /etc/apache2/sites-available/test.com.conf
Open the new file in your editor:
sudo nano /etc/apache2/sites-available/test.com.conf
Then change the relevant settings to reference your second domain. When you are finished, your file will look like this:
/etc/apache2/sites-available/test.com.conf
<VirtualHost *:80>
ServerAdmin [email protected]
ServerName test.com
ServerAlias www.test.com
DocumentRoot /var/www/test.com/public_html
ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
Save and close the file.
Now that we have created our virtual host files, we can enable them.
Step 4 — Enabling the New Virtual Host Files
You've created the folders and the virtual host configuration files, but Apache won't use them until you activate them. You can use the a2ensite tool to enable each of your sites.
Activate the first site:
sudo a2ensite example.com.conf
You'll see the following output if there were no syntax errors or typos in your file:
Output
Enabling site example.com. To activate the new configuration, you need to run: service apache2 reload
In order for your changes to take effect, you have to reload Apache. But before you do, enable the other site:
sudo a2ensite test.com.conf
You'll see a similar message indicating the site was enabled:
Output
Enabling site test.com. To activate the new configuration, you need to run: service apache2 reload
Next, disable the default site defined in 000-default.conf by using the a2dissite command:
sudo a2dissite 000-default.conf
Now, restart Apache:
sudo systemctl restart apache2
The sites are now configured. Let's test them out. If you're using real domains configured to point to your server's IP address, you can skip the next step. But if your domains haven't propogated yet, or if you're just testing, read on to learn how to test this setup using your local computer.
Step 5 — Setting Up Local Hosts File (Optional)
If you haven't been using actual domain names that you own to test this procedure and have been using some example domains instead, you can at least test the functionality of this process by temporarily modifying the hosts file on your local computer.
This will intercept any requests for the domains that you configured and point them to your VPS server, just as the DNS system would do if you were using registered domains. This will only work from your computer though, and is only useful for testing purposes.
Make sure you follow these steps on your local computer, and not your VPS server. You will also need to know the local computer's administrative password or be a member of the administrative group.
If you are on a Mac or Linux computer, edit your local file with administrative privileges by typing:
sudo nano /etc/hosts
If you're on Windows, open a Command Prompt with administrative privileges and type:
notepad %windir%\system32\drivers\etc\hosts
Once you have the file open, add a line that maps your server's public IP address to each domain name, as shown in the following example:
/etc/hosts
127.0.0.1 localhost
...
111.111.111.111 example.com
111.111.111.111 test.com
This will direct any requests for example.com and test.com on your computer and send them to your server at 111.111.111.111.
Save and close the file. Now you can test out your setup. When you're confident things are working, remove the two lines from the file.
Step 6 — Testing Your Results
Now that you have your virtual hosts configured, you can test your setup easily by going to the domains that you configured in your web browser. Visit the first site at http://example.com and you'll see a page that looks like this:
Likewise, if you can visit your second host at http://test.com, you'll see the file you created for your second site:
If both of these sites work well, you've successfully configured two virtual hosts on the same server.
Note:If you adjusted your home computer's hosts file as shown in Step 5, you may want to delete the lines you added now that you verified that your configuration works. This will prevent your hosts file from being filled with entries that are not actually necessary.
Conclusion
You now have a single server handling two separate domain names. You can expand this process by following these steps to add additional virtual hosts.
There is no software limit on the number of domain names Apache can handle, so feel free to make as many as your server is capable of handling.
To use Apache to serve secure content, follow the tutorial How To Secure Apache with Let's Encrypt on Debian 8. To use Apache in front of your web application, follow How To Use Apache as a Reverse Proxy with mod_proxy on Debian 8.
by Brian Hogan