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Monday—Friday: 08:00–16:00

How To Set Up Apache Virtual Hosts on Ubuntu 16.04


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 that can be customized and configured independently. The basic unit that describes an individual site or domain is called a virtual host.

These designations allow the administrator to use one server to host multiple domains or sites off of a single interface or IP by using a matching mechanism. This is relevant to anyone looking to host more than one site off of a single VPS.

Each domain that is configured will direct the visitor to a specific directory holding that site’s information, never indicating that the same server is also responsible for other sites. This scheme is expandable without any software limit as long as your server can handle the load.

In this guide, we will walk you through how to set up Apache virtual hosts on an Ubuntu 16.04 VPS. During this process, you’ll learn how to serve different content to different visitors depending on which domains they are requesting.


Before you begin this tutorial, you should create a non-root user as described in steps 1-4 here.

You will also need to have Apache installed in order to work through these steps. If you haven’t already done so, you can get Apache installed on your server through apt-get:

  • sudo apt-get update
  • sudo apt-get install apache2

After these steps are complete, we can get started.

For the purposes of this guide, our configuration will make a virtual host for example.com and another for test.com. These will be referenced throughout the guide, but you should substitute your own domains or values while following along.

To learn how to set up your domain names with DigitalOcean, follow this link. If you do not have domains available to play with, you can use dummy values.

We will show how to edit your local hosts file later on to test the configuration if you are using dummy values. This will allow you to test your configuration from your home computer, even though your content won’t be available through the domain name to other visitors.

Step One — Create 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 here for both of the virtual hosts we plan on making.

Within each of these directories, we will create a public_html folder that will hold our actual files. This gives us some flexibility in our hosting.

For instance, for our sites, we’re going to make our directories like this:

  • sudo mkdir -p /var/www/example.com/public_html
  • sudo mkdir -p /var/www/test.com/public_html

The portions in red represent the domain names that we are wanting to serve from our VPS.

Step Two — Grant Permissions

Now we have the directory structure for our files, but they are owned by our root user. If we want our regular user to be able to modify files in our web directories, we can change the ownership by doing this:

  • sudo chown -R $USER:$USER /var/www/example.com/public_html
  • sudo chown -R $USER:$USER /var/www/test.com/public_html

The $USER variable will take 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:

  • sudo chmod -R 755 /var/www

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.

Step Three — Create Demo Pages for Each Virtual Host

We have our directory structure in place. Let’s create some content to serve.

We’re just going for a demonstration, so our pages will be very simple. We’re just going to make an index.html page for each site.

Let’s start with example.com. We can open up an index.html file in our editor by typing:

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

In this file, create a simple HTML document that indicates the site it is connected to. My file looks like this:

    <title>Welcome to Example.com!</title>
    <h1>Success!  The example.com virtual host is working!</h1>

Save and close the file when you are finished.

We can copy this file to use as the basis for our second site by typing:

  • cp /var/www/example.com/public_html/index.html /var/www/test.com/public_html/index.html

We can then open the file and modify the relevant pieces of information:

  • nano /var/www/test.com/public_html/index.html
    <title>Welcome to Test.com!</title>
  <body> <h1>Success!  The test.com virtual host is working!</h1>

Save and close this file as well. You now have the pages necessary to test the virtual host configuration.

Step Four — Create New Virtual Host Files

Virtual host files are the files that 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 we can use as a jumping off point. We are going to copy it over to create a virtual host file for each of our domains.

We will start with one domain, configure it, copy it for our second domain, and then make the few further adjustments needed. The default Ubuntu configuration requires that each virtual host file end in .conf.

Create the First Virtual Host File

Start by copying the file for the first domain:

  • sudo cp /etc/apache2/sites-available/000-default.conf /etc/apache2/sites-available/example.com.conf

Open the new file in your editor with root privileges:

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

The file will look something like this (I’ve removed the comments here to make the file more approachable):

<VirtualHost *:80>
    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/html
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

As you can see, there’s not much here. We will customize the items here for our first domain and add some additional directives. This virtual host section matches any requests that are made on port 80, the default HTTP port.

First, we need to change the ServerAdmin directive to an email that the site administrator can receive emails through.

ServerAdmin admin@example.com

After this, we need to add two directives. The first, called ServerName, establishes the base domain that should match for this virtual host definition. This will most likely be your domain. The second, called ServerAlias, defines further names that should match as if they were the base name. This is useful for matching hosts you defined, like www:

ServerName example.com
ServerAlias www.example.com

The only other thing we need to change for a basic virtual host file is the location of the document root for this domain. We already created the directory we need, so we just need to alter the DocumentRootdirective to reflect the directory we created:

DocumentRoot /var/www/example.com/public_html

In total, our virtualhost file should look like this:

<VirtualHost *:80>
    ServerAdmin admin@example.com
    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

Save and close the file.

Copy First Virtual Host and Customize for Second Domain

Now that we have our first virtual host file established, we can create our second one by copying that file and adjusting it as needed.

Start by copying it:

  • sudo cp /etc/apache2/sites-available/example.com.conf /etc/apache2/sites-available/test.com.conf

Open the new file with root privileges in your editor:

  • sudo nano /etc/apache2/sites-available/test.com.conf

You now need to modify all of the pieces of information to reference your second domain. When you are finished, it may look something like this:

<VirtualHost *:80>
    ServerAdmin admin@test.com
    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

Save and close the file when you are finished.

Step Five — Enable the New Virtual Host Files

Now that we have created our virtual host files, we must enable them. Apache includes some tools that allow us to do this.

We can use the a2ensite tool to enable each of our sites like this:

  • sudo a2ensite example.com.conf
  • sudo a2ensite test.com.conf

Next, disable the default site defined in 000-default.conf:

  • sudo a2dissite 000-default.conf

When you are finished, you need to restart Apache to make these changes take effect:

  • sudo systemctl restart apache2

In other documentation, you may also see an example using the service command:

  • sudo service apache2 restart

This command will still work, but it may not give the output you’re used to seeing on other systems, since it’s now a wrapper around systemd’s systemctl.

Step Six — Set 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 simply useful for testing purposes.

Make sure you are operating on your local computer for these steps and not your VPS server. You will need to know the computer’s administrative password or otherwise 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 are on a Windows machine, you can find instructions on altering your hosts file here.

The details that you need to add are the public IP address of your VPS server followed by the domain you want to use to reach that VPS.

For the domains that I used in this guide, assuming that my VPS IP address is, I could add the following lines to the bottom of my hosts file:

/etc/hosts   localhost   guest-desktop example.com test.com

This will direct any requests for example.com and test.com on our computer and send them to our server at This is what we want if we are not actually the owners of these domains in order to test our virtual hosts.

Save and close the file.

Step Seven — Test 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:


You should see a page that looks like this:

Apache virt host example

Likewise, if you can visit your second page:


You will see the file you created for your second site:

Apache virt host test

If both of these sites work well, you’ve successfully configured two virtual hosts on the same server.

If you adjusted your home computer’s hosts file, 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.

If you need to access this long term, consider purchasing a domain name for each site you need and setting it up to point to your VPS server.


If you followed along, you should now have a single server handling two separate domain names. You can expand this process by following the steps we outlined above to make 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.


  • https://www.digitalocean.com/community/tutorials/how-to-set-up-apache-virtual-hosts-on-ubuntu-16-04

 Install PHP in Ubuntu 18.04

To install PHP, run:

$ sudo apt install php libapache2-mod-php php-mysql

After installing PHP, create info.php file in the Apache root document folder. Usually, the apache root document folder will be /var/www/html/ or /var/www/ in most Debian based Linux distributions. In Ubuntu 18.04 LTS, it is /var/www/html/.

Create test.php in the apache root folder as shown below.

$ sudo vi /var/www/html/info.php

Add the following lines:


Save and quit the file. Restart apache service to take effect the changes.

$ sudo systemctl restart apache2

Now, open up your web browser and type: http://IP-address/info.php in the address bar.

You will be pleased with a screen like below.

Install PHP modules

To improve the functionality of PHP, you can install some additional PHP modules.

To list the available PHP modules, run:

$ sudo apt-cache search php- | less

Sample output:

Use and arrows to move up and down between the result. To exit from the result, type q.

To find the details of any particular php module, for example php-gd, run:

$ sudo apt-cache show php-gd

To install a php module run:

$ sudo apt install php-gd

To install all modules (not necessary though), run:

$ sudo apt-get install php*

Do not forget to restart Apache service after installing any php module.

Install Apache in Ubuntu 18.04

For the purpose of this tutorial, I will be using the following testbox.

  • Operating System : Ubuntu 18.04 64 bit LTS server
  • IP address :

Install Apache webserver

To install Apache web server, run the following command from the Terminal:

$ sudo apt install apache2

Check if Apache web server is running or not:

$ sudo systemctl status apache2
● 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
Active: active (running) since Fri 2018-07-06 11:42:35 UTC; 27s ago
Main PID: 2079 (apache2)
Tasks: 55 (limit: 2322)
CGroup: /system.slice/apache2.service
├─2079 /usr/sbin/apache2 -k start
├─2081 /usr/sbin/apache2 -k start
└─2082 /usr/sbin/apache2 -k start

Jul 06 11:42:35 ubuntuserver systemd[1]: Starting The Apache HTTP Server...
Jul 06 11:42:35 ubuntuserver systemd[1]: Started The Apache HTTP Server.

Apache service is loaded and running!

Adjust firewall to allow Apache web server

By default, the apache web browser can’t be accessed from remote systems if you have enabled the UFW firewall in Ubuntu 18.04 LTS. You must allow the http and https traffic via UFW by following the below steps.

First, let us view which applications have installed a profile using command:

$ sudo ufw app list
Available applications:
Apache Full
Apache Secure

As you can see, Apache and OpenSSH applications have installed UFW profiles.

If you look into the “Apache Full” profile, you will see that it enables traffic to the ports 80 and 443:

$ sudo ufw app info "Apache Full"
Profile: Apache Full
Title: Web Server (HTTP,HTTPS)
Description: Apache v2 is the next generation of the omnipresent Apache web


Now, run the following command to allow incoming HTTP and HTTPS traffic for this profile:

$ sudo ufw allow in "Apache Full"
Rules updated
Rules updated (v6)

If you want to allow https traffic, but only http (80) traffic, run:

$ sudo ufw app info "Apache"

Now, open up your web browser and navigate to http://localhost/ or http://IP-Address/.

If you are see a screen something like above, you are good to go. Apache server is working!


  • https://www.ostechnix.com/install-apache-mariadb-php-lamp-stack-ubuntu-16-04/

Setting IP Address (Ubuntu 18.04)

Based on this you configuration in .yaml (sudo /etc/netplan/50-xxxx.yaml) can be:

# This file describes the network interfaces available on your system
# For more information, see netplan(5).
  version: 2
  renderer: networkd
      dhcp4: no
      dhcp6: no
      addresses: []
        addresses: [,]

Or some appropriate netmask.

Netmask cannot be Netmask for class C addresses can be:

Prefix size         | Subnet mask   
/24                 | 
/25                 |
/26                 |
/27                 |
/28                 |
/29                 |
/30                 |
# sudo netplan apply

How To Install R on Ubuntu 18.04


R is an open-source programming language that specializes in statistical computing and graphics. In this tutorial, we will install R on an Ubuntu 18.04 server.

For a more detailed version of this tutorial, with better explanations of each step, please refer to How To Install R on Ubuntu 18.04.

Step 1 — Add GPG Key

The Ubuntu archives on CRAN are signed with the key of “Michael Rutter ” with key ID 0x51716619e084dab9. To add the key to your system with one command use (thanks to Brett Presnell for the tip):

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9

An alternate method can be used by retrieving the key with

gpg --keyserver keyserver.ubuntu.com --recv-key E298A3A825C0D65DFD57CBB651716619E084DAB9

and then feed it to apt-key with

gpg -a --export E298A3A825C0D65DFD57CBB651716619E084DAB9 | sudo apt-key add -

Some people have reported difficulties using this approach. The issue is usually related to a firewall blocking port 11371. If the first gpg command fails, you may want to try (thanks to Mischan Toosarani for the tip):

gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9

and then feed it to apt-key with

gpg -a --export E298A3A825C0D65DFD57CBB651716619E084DAB9 | sudo apt-key add -

Another alternative approach is to search for the key at http://keyserver.ubuntu.com:11371/ and copy the key to a plain text file, say key.txt. Then, feed the key to apt-key with

sudo apt-key add key.txt

Step 2 — Add the R Repository

To obtain the latest R 4.0 packages, add an entry like

deb https://cloud.r-project.org/bin/linux/ubuntu focal-cran40/


deb https://cloud.r-project.org/bin/linux/ubuntu bionic-cran40/


deb https://cloud.r-project.org/bin/linux/ubuntu xenial-cran40/

Step 3 — Update Package Lists

  • sudo apt update

Step 4 — Install R

  • sudo apt install r-base r-base-dev

If prompted to confirm installation, press y to continue.

Step 5 — Test Install

Start R’s interactive shell as root.

  • sudo -i R

You should receive output similar to the following:


R version 3.5.1 (2018-07-02) -- "Feather Spray"
Copyright (C) 2018 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.


This confirms that we’ve successfully installed R and entered its interactive shell.


  • https://www.digitalocean.com/community/tutorials/how-to-install-r-on-ubuntu-18-04-quickstart

Installing MariaDB on Ubuntu 18.04 from the MariaDB Repositories

At the time of writing this article, the latest version of MariaDB available from the official MariaDB repositories is MariaDB version 10.3. Before continuing with the next step you should visit the MariaDB Repository page and check if there is a new version available.

To install MariaDB 10.3 on your Ubuntu 18.04 server perform the following steps:

  1. First add the MariaDB GPG key to your system using the following command:
    sudo apt-key adv --recv-keys --keyserver hkp://keyserver.ubuntu.com:80 0xF1656F24C74CD1D8


  2. Once the key is imported, add the MariaDB repository with:
    sudo add-apt-repository 'deb [arch=amd64,arm64,ppc64el] http://ftp.utexas.edu/mariadb/repo/10.3/ubuntu bionic main'


    If you get an error message saying add-apt-repository command not found install the software-properties-common package.

  3. To be able to install packages from the MariaDB repository you’ll need to update the packages list:
    sudo apt update


  4. Now that the repository is added install the MariaDB package with:
    sudo apt install mariadb-server


  5. The MariaDB service will start automatically, to verify it type:
    sudo systemctl status mariadb


    ● mariadb.service - MariaDB 10.3.8 database server
    Loaded: loaded (/lib/systemd/system/mariadb.service; enabled; vendor preset: enabled)
    Drop-In: /etc/systemd/system/mariadb.service.d
    Active: active (running) since Sun 2018-07-29 19:36:30 UTC; 56s ago
        Docs: man:mysqld(8)
    Main PID: 16417 (mysqld)
    Status: "Taking your SQL requests now..."
        Tasks: 31 (limit: 507)
    CGroup: /system.slice/mariadb.service
            └─16417 /usr/sbin/mysqld


    And print the MariaDB server version, with:

    mysql -V


    mysql  Ver 15.1 Distrib 10.3.8-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2


Run the mysql_secure_installation command to improve the security of the MariaDB installation:

sudo mysql_secure_installation


The script will prompt you to set up the root user password, remove the anonymous user, restrict root user access to the local machine and remove the test database. At the end the script will reload the privilege tables ensuring that all changes take effect immediately.

All steps are explained in detail and it is recommended to answer “Y” (yes) to all questions.

To connect to the MariaDB server through the terminal we can use the MariaDB client.

To log in to the MariaDB server as the root user type:

mysql -u root -p


You will be prompted to enter the root password you have previously set when the mysql_secure_installation script was run.

Once you enter the password you will be presented with the MariaDB shell as shown below:

Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 49
Server version: 10.1.29-MariaDB-6 Ubuntu 18.04

Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

Fix MariaDB Plugin ‘Unix_socket’ Is Not Loaded Error On Ubuntu 18.04

Step 1: Add Unix Authentication Plugin To MariaDB Config

If this issue relates to Unix authentication plugin, the quickest fix is to open MariaDB configuration file and add a single line into the file and save. Run the commands below to open MariaDB default configuration file.

sudo nano /etc/mysql/mariadb.conf.d/50-server.cnf

Then add the line below [mysqld] section.

plugin-load-add = auth_socket.so

After adding the line into the file, run the commands below to restart MariaDB

sudo systemctl restart mariadb.service

Next, try to sign  on to the database again.

sudo mysql -u root

Running the commands above should logon onto the database without password prompt… that’s because it’s using unix socket authentication.

Step 2: Change To Standard Authentication

Step 1 should be enough to get you into MariaDB server… and should work as long as you keep using unix socket authentication. However, other apps and services like phpMyAdmin that depend on standard password authentication will stop working when you enable socket authentication for the root user.

A typical error you’ll get when unix socket authentication is being used will be  ERROR 1698 (28000): Access denied for user ‘root’@’localhost’

So now that you’ve access to the database, run the commands below to disable unix socket authentication for the root user…

use mysql;
update user set plugin='' where User='root';
flush privileges;

Exit out and you’re done. Now you should be able to logon to the server with standard password authentication.

That’s it!


  • https://linuxize.com/post/how-to-install-mariadb-on-ubuntu-18-04/
  • https://websiteforstudents.com/fix-mariadb-plugin-unix_socket-is-not-loaded-error-on-ubuntu-17-04-17-10/
November 2018