Chapter 2. Logging In

Logging in with Netscape or Internet Explorer

Logging into Webmin is easy. Open a web browser, such as Netscape or Internet Explorer, on any machine that has network access to the server on which you wish to login. Browse to port 10000 on the IP or host name of the server, as shown in figure 2-1.

Figure 2.1. Entering the URL

Webmin will then respond with either an authentication window, or an authentication web form, in which you can enter the adminstrator user name (usually “root” or “admin”) and password. After successful authentication, you will be greeted with the Webmin index page. The type of login form you receive (either on a web page or in a popup window) depends on the configuration of the Webmin server. The differences between session authentication (Figure 2.2, “Session Authentication”) and standard HTTP authentication are discussed later in the book.

Figure 2.2. Session Authentication

Note

Many systems are configured with Webmin running in SSL encrypted mode. On these systems, you will log in using a URL beginning with https:// rather than http://. Also, at least one Linux distribution that includes Webmin, specifically Caldera, installs it on port 1000 rather than 10000. This is theoretically a more secure arrangement, however, be aware that some firewalls will prevent you from accessing your Webmin-enabled server from outside of the local network if Webmin runs on a port below 1024.

Logging in with Lynx

Sometimes, it may be desirable or necessary to administer your system from the command line without the benefit of a GUI. Luckily, one does not have to give up Webmin entirely in these circumstances. Using Lynx, or a similarly capable text-mode web browser, one can login and use most of the Webmin modules much the same as using a graphical browser. Logging in when Webmin is using session authentication is identical to logging in with a graphical browser, but logging in when Webmin is configured to use traditional HTTP authentication is slightly different. Lynx requires that authentication information be included on the command line when starting up:

[joe@delilah joe]$ lynx -auth root:passwd http://delilah:10000

Caution

If you plan to administer your system via a text mode browser, you will want to choose an alternate theme rather than the new default MSC.Linux theme. The old default theme, or the Swell Technology theme have a simpler icon and table layout, allowing Lynx and other text-mode browsers to display them more effectively. The MSC.Linux theme, while attractive in a GUI browser, uses a complex layout that leads many areas of Webmin to be difficult to read and impossible to use in a text mode browser.

Another limitation of using a command line client is that SSL is not well supported by all versions of Lynx and other text-mode browsers. This means you may need to run your Webmin server without encryption; therefore, more extreme measures should be taken to insure the security of your server. Securing a Webmin installation will be discussed in detail in later chapters.

A First Look

Webmin is divided into a number of modules that each allow you to administer a single aspect of your system. Modules exist for most common, and many uncommon, system administration tasks. The standard modules provide a graphical interface for: Apache, Squid, Bind, NFS, man pages, Sendmail, Postfix, Samba, and much more. There also exist a wide array of third party modules that provide even more extensive functionality. This book focuses on the standard modules, but may expand to encompass other modules in time.

Upon first logging in, you'll see a row of tabs and a number of icons (Figure 2.3, “A First Look”). The tabs are labeled Webmin, System, Servers, Hardware, Cluster, and Others. You may also have, depending on your OS and version, one or two additional tabs. The selected tab when first logging in is always Webmin. This category is where all of the Webmin-related configuration details are located.

Figure 2.3. A First Look

The view from Lynx is actually pretty similar if using one of the traditional themes (Figure 2.4, “A first look from Lynx”). The MSC.Linux theme makes many links inaccessible when using Lynx; overall usage is quite difficult when you're working in a text-mode browser, so be sure to switch to a more conventional theme if you'll be administering your system from the command line. On my server using the Swell Technology theme, Webmin is quite useable entirely from a text console, making Webmin useful even when no browser is available. The MSC.Linux theme can also be rather heavy-weight when administering a server across a WAN link with a graphical browser. This is because the number and size of images makes browsing the pages rather slow even via a fast connection.

Figure 2.4. A first look from Lynx

Because Webmin is web-based, interacting with the GUI will probably be immediately comfortable, though for beginners it may take a few minutes to locate specific modules or features. In the following chapters, the discussion will focus on specific Webmin modules and the services that the modules configure. It proceeds through the category tabs from left to right, beginning with Webmin and ending with Others.