How to Install Webmin on Debian 12

Introduction

Webmin is a web-based interface for managing Unix-like systems through a browser, eliminating the need to manually edit configuration files from the command line. It allows you to easily perform system administration tasks such as adding users, setting disk quotas, managing software packages, configuring networks, and controlling databases. Webmin is highly extensible, supporting a wide range of open-source tools to enhance server functionality. Installing Webmin on Debian 12, a stable and secure long-term support release, provides a user-friendly and efficient way to manage your server with greater control and flexibility.

This article explains how to install Webmin on Debian 12 and enable access to the web-based graphical interface. If you're working with a different Linux distribution, you might also find these guides helpful: How to Install Webmin on Ubuntu 24.04 and How to Install Webmin on Rocky Linux 9.

Prerequisites

Before you begin:

• Deploy a Debian 12 instance on Vultr.
• Create a domain name A record pointing to the instance's public IP address. For example, webmin.example.com.
• Access the instance using SSH as a non-root user with sudo privileges.
• Update the instance.

Install Webmin on Debian 12

Webmin is not available in the default package repositories on Debian 12. Follow the steps below to download the latest Webmin repository information script and install the application.

1. Download the latest Webmin repository setup script and save it as setup-repos.sh.

   console Copy

   $ curl -o setup-repos.sh https://raw.githubusercontent.com/webmin/webmin/master/setup-repos.sh
   

2. Run the script using the Bash interpreter.

   console Copy

   $ sudo bash setup-repos.sh
   

   Enter Y and press Enter when prompted to proceed with the repository installation. When successful, your output should be similar to the one below.

   Setup repository? (y/N) y
       Downloading Webmin key ..
       .. done
       Installing Webmin key ..
       .. done
       Setting up Webmin repository ..
       .. done
       Cleaning repository metadata ..
       .. done
       Downloading repository metadata ..
       .. done
   Webmin package can now be installed using apt-get install --install-recommends webmin command.

3. Update your system's package information index to apply the Webmin repository information.

   console Copy

   $ sudo apt update
   

4. Install Webmin and the default recommended packages.

   console Copy

   $ sudo apt install webmin --install-recommends -y
   

5. Enable the Webmin service to automatically start at system boot.

   console Copy

   $ sudo systemctl enable webmin
   

6. Start the Webmin service.

   console Copy

   $ sudo systemctl start webmin
   

7. View the Webmin system service status and verify it's running.

   console Copy

   $ sudo systemctl status webmin
   

   Output:

   ● webmin.service - Webmin server daemon
        Loaded: loaded (/lib/systemd/system/webmin.service; enabled; preset: enabled)
        Active: active (running) since Mon 2024-08-19 14:15:47 EDT; 42s ago
      Main PID: 4614 (miniserv.pl)
         Tasks: 1 (limit: 4572)
        Memory: 125.7M
           CPU: 2.060s
        CGroup: /system.slice/webmin.service
               └─25004614 /usr/bin/perl /usr/share/webmin/miniserv.pl /etc/webmin/miniserv.conf

   Webmin is active and running based on the above output information.

Secure Webmin

Webmin runs on the default TCP port 10000 and serves the web administration control panel using HTTP. Generate trusted SSL certficates to secure network connections to the Webmin interface using HTTPS. Follow the steps below to install the Certbot Let's Encrypt client and enable Webmin to use trusted SSL certificate files.

1. Allow HTTP traffic on the default port 80 to enable Let's Encrypt validations.

   console Copy

   $ sudo ufw allow 80/tcp
   

2. Restart UFW to apply the new changes.

   console Copy

   $ sudo ufw reload
   

3. Install the Certbot Let's Encrypt client tool.

   console Copy

   $ sudo apt install certbot -y
   

4. Generate a new SSL certificate for your domain. Replace webmin.example.com with your domain and webmin@example.com with your actual email address.

   console Copy

   $ sudo certbot certonly --standalone -d webmin.example.com -m webmin@example.com --agree-tos
   

   Your output should be similar to the one below when successful.

   ...
   Successfully received certificate.
   Certificate is saved at: /etc/letsencrypt/live/webmin.example.com/fullchain.pem
   Key is saved at:         /etc/letsencrypt/live/webmin.example.com/privkey.pem
   ...

   Certbot stores the SSL certificate and private key files in the /etc/letsencrypt/live/webmin.example.com/ directory based on the above output.

5. Combine the SSL certificate and private key contents into a single file such as webmin_key_cert.pem.

   console Copy

   $ sudo cat /etc/letsencrypt/live/webmin.example.com/fullchain.pem /etc/letsencrypt/live/webmin.example.com/privkey.pem > webmin_key_cert.pem
   

6. Move the file to the /etc/webmin/ Webmin data directory.

   console Copy

   $ sudo mv webmin_key_cert.pem /etc/webmin/
   

7. Open the /etc/webmin/miniserv.conf Webmin configuration file using a text editor like nano.

   console Copy

   $ sudo nano /etc/webmin/miniserv.conf
   

8. Find the keyfile directive and replace the value with your webmin_key_cert.pem SSL certificate path.

   ini Copy

   keyfile=/etc/webmin/webmin_key_cert.pem
   

9. Restart the Webmin service to apply the configuration changes.

   console Copy

   $ sudo systemctl restart webmin
   

Set Up Firewall Rules

Uncomplicated Firewall (UFW) is available and active on Vultr Debian instances by default. Follow the steps below to set up new firewall rules and allow network connections to the Webmin interface.

1. View the UFW status and verify that it's active.

   console Copy

   $ sudo ufw status
   

2. Allow network connections to the default Webmin port 10000.

   console Copy

   $ sudo ufw allow 10000/tcp
   

3. Allow incoming HTTPS connections.

   console Copy

   $ sudo ufw allow https
   

4. Deny incoming HTTP connections to disable insecure requests.

   console Copy

   $ sudo ufw deny http
   

5. Reload UFW to apply the firewall changes.

   console Copy

   $ sudo ufw reload
   

6. View the UFW status and verify the new connection rules are available.

   console Copy

   $ sudo ufw status
   

   Output:

   
   Status: active
   
   To                         Action      From
   --                         ------      ----
   443                        ALLOW       Anywhere
   80                         ALLOW       Anywhere
   80/tcp                     DENY        Anywhere
   OpenSSH                    ALLOW       Anywhere
   10000/tcp                  ALLOW       Anywhere
   443 (v6)                   ALLOW       Anywhere (v6)
   80 (v6)                    ALLOW       Anywhere (v6)
   80/tcp (v6)                DENY        Anywhere (v6)
   OpenSSH (v6)               ALLOW       Anywhere (v6)
   10000/tcp (v6)             ALLOW       Anywhere (v6)

Access Webmin

Webmin listens for incoming connection requests on the default port 10000 based on the /etc/webmin/miniserve.conf configuration. Follow the steps below to access the Webmin web administration interface on port 10000.

1. Access your domain on port 10000 using a web browser such as Chrome.

   https://webmin.example.com:10000

2. Enter your non-root sudo user credentials when prompted to log in to the Webmin interface.

   

3. Click Dashboard on the main navigation menu to access the system information summary.

   

Conclusion

You have installed Webmin on a Debian 12 and secured the control panel interface with trusted Let's Encrypt SSL certificates. Webmin lets you use a GUI to manage and monitor your system applications and services. For more information, please visit the Webmin documentation.