How to Configure and Install Webmin on Ubuntu 18.04

Webmin is a web-based control panel that is used for the administration of Linux systems. It is written in Perl and helps systems administrators to have an overview of their server performance at a glance.

Webmin eliminates the hassle of manually creating user accounts, groups, system update, configuring email, database, etc. In this tutorial, we will show you how you can install and secure Webmin on Ubuntu 18.04.

Prerequisites

Before we get started, ensure you have the following in place

• An instance of Ubuntu 18.04 server set up
• Nginx webserver installed
• A Fully Qualified Domain Name (FQDN) with the DNS A record pointing to the server's address.
• Let's encrypt SSL installed using certbot

Let's now take a step by step approach and install webmin

Install webmin

To start off, we need to append Webmin's repository to enable us to seamlessly install and manage Webmin using the apt package manager. But before we do so, let's update our system repositories

$ sudo apt update

Next, install the necessary packages

$ sudo apt install python apt-show-versions libapt-pkg-perl libauthen-pam-perl libio-pty-perl libnet-ssleay-perl

Sample output

Thereafter, download the Webmin deb package

$ cd /tmp && curl -L -O http://www.webmin.com/download/deb/webmin-current.deb

Now install Webmin using the command below

$ sudo dpkg -i webmin-current.deb

Accessing Webmin

Not that we have successfully installed Webmin, we are going to allow port 10000 in the firewall. This is the port which we are going to access Webmin's interface.

To add port 10000 in ufw firewall execute

$ sudo ufw allow 10000/tcp

Output

To verify that port 10000 is open, run

$ sudo ufw status

Output

With the port allowed in the firewall head out to your browser, and browse your domain with the suffix  :10000 at the end of the URL

Syntax

https://samplewebsite.com:10000

The URL bar will show you that the site is not encrypted and the above page will open. This is because Webmin does not yet have an SSL certificate which we shall proceed to install.

To proceed to the main dashboard, click on the "Advanced"  tab and click on proceed to URL address

You will be presented with a login screen as shown. Enter the correct user details and click on 'Sign in'

The dashboard below will appear

Set up the document root directory

Next, we are going to configure Nginx server block. By default, Nginx has only one server block which is configured to server documents from /var/www/html directory

We are now going to set up a root directory for our site.

Syntax

$ sudo mkdir -p /var/www/samplewebiste.com/html

With our directory in place, we are going to reassign ownership  to our regular user account

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

Modify permissions

$ sudo chmod -R 755 /var/www

Configure Nginx server block

Nginx contains one server block called default  by default which we can use as a template for our own configurations. Weare going to create our domain's server block and later copy the default server to it and make some modifications.

As indicated above, we shall create our first server block config file by copying over the default file:

$ sudo cp /etc/nginx/sites-available/default /etc/nginx/sites-available/samplewebiste.com

We are then going to open the file using a text editor and make a few changes

$ sudo vim /etc/nginx/sites-available/samplewebiste.com

Ignoring the commented lines, the configuration should resemble the one below

server {
        listen 80 default_server;
        listen [::]:80 default_server;

        root /var/www/html;
        index index.html index.htm index.nginx-debian.html;

        server_name _;

        location / {
                try_files $uri $uri/ =404;
        }
}

Since we already have the Nginx default server block with the default_server attribute in the server block, we are going to delete the attribute in our domain and have :

server {
     listen 80;
        listen [::]:80;

        . . .
}

We are then going to adjust the path to our document root and point it to our server's document root

server {
listen 80;
listen [::]:80;

root /var/www/samplewebiste.com/html;


}

Modify the server_name attribute to match our domain

server {
        listen 80;
        listen [::]:80;

        root /var/www/samplewebiste.com/html;
        index index.html index.htm index.nginx-debian.html;

        server_name samplewebiste.com www.samplewebiste.com;

        location / {
                try_files $uri $uri/ =404;
        }
}

Close and exit the configuration file

We are then going to enable the server block by issuing the following command

$ sudo ln -s /etc/nginx/sites-available/samplewebiste.com/etc/nginx/sites-enabled/

To ensure that there are no syntactical errors in any of our Nginx files, execute

$ sudo nginx -t

Output

Great!! Let's now restart Nginx server

$ sudo systemctl restart nginx

To verify that Nginx is running execute

$ sudo systemctl status nginx

Output

Encrypting Webmin

The final part is securing Webmin to encrypt communication between the browser and the Webmin server.

Click on the 'Webmin' tab

Select 'Web configuration' in the drop-down menu that appears

Click on SSL 'Encryption'

Next, Click on the  'Let's  Encrypt' tab. Fill out the hostname in the hostname tab and define the root directory for the validation file as shown. Thereafter click on 'Request Certificate'.

Webmin will b generate Let's encrypt SSL certificate  and store the validation file in the website directory defined

Go back to the URL and refresh the browser. You will now notice that the connection to the Webmin server is encrypted.

You can now log in securely and access the dashboard

To view information about the certificate, click on the padlock symbol and select 'Certificate valid' option

Certificate Information

Conclusion

You have come this far, you should be in a position to install Webmin with SSL support using Let's Encrypt certificate. Try it out on your server and let us know your experience.

Related: How to Install Webmin on Ubuntu 20.04