Webmin is a web-based interface for system administration on any UNIX machine. The interface can be used with any modern web browser. As long as you have access to the server Webmin is installed on, you can administer that machine.
When Webmin was released years ago, it filled the spot of the Linuxconf tool that was being phased out, and the tool was a smash hit. Webmin is still one of the most powerful administration tools you will find for a UNIX environment.
Built-in modules and features
Webmin includes built-in modules for the following and more:
- Bandwidth Monitoring
- CD Burner
- Disks and network filesystems
- File manager
- Mail filter/forwarder
- FTP Proxy
- Boot loader
- HTTP Tunnel
- IPsec VPN
- Log filesystems
- MIME Types
- MON Service
For a complete list of services available to Webmin, check out the Standard Modules page.
Webmin also features:
- A built-in update tool
- Quick access to system information
- An easy to use interface
- Expansion via easy to install modules
It’s incredibly easy to install Webmin. Binary packages have been created and are available for download on the Webmin download page, where you will find the following packages:
- RPM — for RedHat, Fedora, CentOS, SUSE, or Mandrake Linux
- DEB — for Debian, Ubuntu, and other derivatives
- PKG — for Solaris
- TAR — for UNIX
- ZIP — for Windows
After you download the file you need for your platform, you need to issue the command associated with the installation. For example, the installation command for the DEB package on a Ubuntu machine is sudo dpkg -i webmin-XXX_all.deb (XXX is the release number).
On the Ubuntu installation (installed on an 11.10 machine), there was an issue with a missing dependency. To resolve this issue, it was just a matter of following these steps:
- Open Synaptic.
- Go to Edit | Fix Broken Packages.
- Click Apply.
After Webmin is installed, it can be reached by pointing a browser to the https://ADDRESS_TO_SERVER:10000 address (ADDRESS_TO_SERVER is the address of the machine Webmin is installed on).
Logging in and security issues
To log in, you need to use credentials that have administrative rights. This can cause problems on a Ubuntu machine because anyone with sudo permissions can log in. To avoid this issue, you can configure only a specific user’s permission to log in. Here’s how:
- Expand the Webmin menu in the left nav.
- Click the Webmin user’s entry.
- Click Unix User Authentication.
- On the resulting page, click the checkbox for Allow Unix Users Listed Below To Log In (Figure A).
- From the Allow drop-down, select Unix User.
- In the User text area, enter the username.
- In the As Webmin User drop-down, select root.
For added security, in the lower section of the page, you can deny users permission to log in to Webmin. (Click the image to enlarge.)
Using a module
From the left navigation, you can expand a section to reveal the delights Webmin has to offer. I encourage you to expand each section to get familiar with what each one offers. Most sections are fairly easy to find. For instance, you will find Apache, SSH, and MySQL Server under Servers, and Bandwidth Monitoring and Firewalls are under Networking.
To configure any aspect of the Webmin system, look under the Webmin entry in the navigation. Webmin | Webmin Configuration holds the majority of the configuration options for the Webmin application (Figure B). From this page you can Upgrade Webmin, Manage Blocked Hosts And Users, Control Access Via IP Address, and Add New Modules.
Below this section, you will find options to set Webmin to start at boot, as well as a button to restart the Webmin daemon. (Click the image to enlarge.)
From the Webmin Configuration panel, it is possible to install new modules for Webmin. (You can find plenty of third-party modules on the Webmin page.) This is the process for installing new modules:
- Download the .wbm.gz file you want to install.
- Go to the Webmin Modules page (click Webmin Configuration | Webmin Modules).
- From the Webmin Modules page, check From Local File (Figure C).
- Click the “…” button associated with From Local File.
- Navigate to the file just downloaded.
- Click OK in the navigation window.
You can also install from a remote source if you have the address of the .wbm.gz file. (Click the image to enlarge.)
After you installed a module, you’ll receive an installation success notification and instructions on where to locate the new module.
In future DIY posts, I’ll dig deeper into how to use some of Webmin’s various modules. Until then, I hope you enjoy familiarizing yourself with your new administration tool.