Preface

Webmin is a web-based graphical Unix system administration tool written by Jamie Cameron in the Perl programming language that is designed to be lightweight, functional, and easily extensible. Webmin has been translated to over 20 languages and dialects at the time of this writing, and has been embraced by a number of hardware and operating system vendors as their default system administration tool. It is extremely portable, offering support for more than 35 different Unix-like Operating Systems and Linux distributions. And it is very easily extended to support new features and options, due to an open and well documented API.

Webmin also happens to be a fast and easy to use tool for general Unix system administration. This document attempts to introduce to you many of the concepts you will need to maintain a Unix system using Webmin. While no single volume can address every aspect of Unix system administration, a real effort has been made to provide both a solid introduction to many important tasks, and a nearly comprehensive reference to a typical Unix server and its parts. It is my hope that with nothing more than this book, a copy of Webmin, and the documentation that accompanies your server, you will be able to configure the system to provide the most popular services, create a reasonable security policy, and manage your users and normal system maintenence tasks. Advanced topics are often covered, but I hope that it will not be at the expense of preventing you from seeing the forest for the trees.

Conventions Used in This Guide

This book is divided into chapters, with each one being devoted to a particular module or section of Webmin. Often, a short introductory section is included at the start of a chapter, that explains the purpose and design of the module and also the function of the underlying software package that is configured by the module. Also, in most cases, one or more tutorials is provided at the end of a chapter to introduce the user to some common functions of the software and how to perform those functions with the Webmin interface.

Type faces have been chosen to indicate the purpose of a word or value. The following type faces have been used in the described manner. Note that some type faces are used for multiple purposes, but context will generally clarify the intention.

Type faces

Italics

Indicates an emphasized word or concept. Also used to indicate the first use of a term in a given context.

Bold

Used to specify a module name, or an individual option within a module. The full path to a given module will be represented by separating each level in the hierarchy seperated by colons in a bold face. For example, the Squid Access Controls module, located under the Servers tab, can be specified with Servers:Squid Proxy Server:Access Control. This form will be used throughout the book.

Fixed width

Indicates an option value, or a directive within a text configuration file. This type face is also used for filenames and directory pathnames, as well as example input on the command line. When text console examples are used, they will also be in this font, and set off from the rest of the text on the page.

When an item is of particular interest, or is of importance for security or compatibility reasons, it will be set off from the rest of the text. A small icon will indicate the type of information and why it has been separated from the normal text. Those icons are used as follows.

This is a note, used to indicate some item of interest or a reference to additional documentation on a subject. Notes may be informational, anecdotal, or referential. I.e. they might make a suggestion, tell a story, or refer you to more extensive documentation on the subject.

This is a warning, used to denote important security information or stability, compatibility, or other information on options that could lead to improper functioning of your server if configured incorrectly. Hopefully, the hammer will remind you that something could get broken if care is not taken.

This indicates a helpful tip. Usually a short recommendation for how to best use a feature or option to make your system easier to administer.