Trying to address everything you can do with Webmin would constitute a year's worth of these columns. Suffice it to say that if it has anything to do with administering your system, odds are pretty good Webmin has it in its clean, consistent, and friendly interface. Figure 3 shows Webmin in action setting up some anti-SPAM rules in sendmail.
Figure 3 Sendmail administration in Webmin.
The default admin options include modules for a wide range of administration functions. From the included modules, you can add users, create and administer printers and queues, modify your Apache server config, set disk quotas, maintain disks and partitions, tweak your DNS, configure sendmail, define SAMBA or NFS shares, configure your PosgreSQL or MySQL server, and ... well, you get the idea. Heck, you can even shutdown or reboot the system. There's even a handy interface for syncing system time with hardware time via a network time server.
One of the greatest features for the overworked administrator is Webmin's self-update feature that makes keeping up to date with the latest version of Webmin completely painless. From the Webmin configuration menu, click Upgrade Webmin and choose the type of update you wish. This can be either a complete upgrade to the latest Webmin or an update of changes.
These changes may be additional modules or patches that have been added since the latest release. To test this feature, I installed a clean version of Webmin 0.92 on a Linux system (the one I used to write this article) and chose this patch update feature. You can view the result by looking at Figure 4. For instance, my bind8 module was updated to version 0.922 and my proftpd module went to level 0.921.
Figure 4 Using the Update feature.
You can make this whole update/upgrade process even easier. The same page lets you schedule automatic updates of your Webmin installation and then have it email you a report of the process. It's a great way to stay on top of changes, particularly when security is an issue and when isn't security an issue? Speaking of which, you can define what addresses are allowed to access Webmin, thus restricting access to trusted hosts if you so wish.
It can be very nice to find all the functions you need in one convenient location, but what about access to other servers? If you have other Webmin servers on your network, Webmin can scan for them and provide access from the Webmin Servers menu just click on Broadcast for Servers if the hosts are local to your network; if not, specify the subnet and click Scan for Servers.
The smart administrator is one who knows when to share the load. At some point, it makes sense to let someone else handle at least some of the administrative duties (even if you do retain executive control). Simply select Webmin Users from the menu and choose Create Webmin user. Decide on a user name, provide a password, and then choose from the extensive list of Webmin modules. Would you like to turn over all duties related to printers and printing to "subadmin1"? Just click the appropriate checkbox. DHCP administration? Same thing.
As you can see, Webmin is a powerful tool. That doesn't mean we can't have some fun with it. For those times when the interface gets just a little too familiar, it's themeable. Select Webmin Themes from the configuration menu and put a fresh face on your favorite admin tool. Personally, I like the default "MSC Linux" theme.
Webmin is a dynamic and exciting project with new features and support being added all the time. If the administrative function you are looking for isn't there, don't despair. A number of people have written third party modules for Webmin. A visit to http://webmin.thirdpartymodules.com won't fail to impress. If what you are looking for isn't there (and you just happen to be a capable programmer), the nice folks developing Webmin would love to hear from you.
I'd like to wrap this up by saying that I hope I've given you plenty of reason why Webmin should be part of your administrative toolkit. This is a wonderful, mature tool that will make your life easier. No sysadmin should be without it. Best of all, with its BSD license, Webmin won't cost you any more than the price of a download.