Managing Linux systems with Webmin: system administration and module development

810 Pages·2004·6.43 MB·English

by  Jamie Cameron

Managing Linux Systems
®
Webmin
with ™

Managing Linux Systems
®
Webmin
with
™
System Administration and Module Development
Jamie Cameron
PRENTICE HALL
PROFESSIONAL TECHNICAL REFERENCE
UPPER SADDLE RIVER, NJ 07458
WWW.PHPTR.COM
Library of Congress Cataloging-in-Publication Data
Cameron, Jamie.
Managing Linux systems with Webmin / Jamie Cameron.
p. cm.
ISBN 0-13-140882-8
1. Linux. 2. Operating systems (Computers). I. Title.
QA76.76.O63 C3545 2003
005.4’32—dc22
2003016330
Editorial and production services: TIPS Technical Publishing, Inc.
Cover design director: Jerry Votta
Cover design: Nina Scuderi
Manufacturing buyer: Maura Zaldivar
Executive Editor: Jill Harry
Editorial assistant: Brenda Mulligan
Marketing manager: Dan DePasquale
© 2004 by Jamie Cameron
Published by Pearson Education, Inc.
Publishing as Prentice Hall Professional Technical Reference
Upper Saddle River, New Jersey 07458
This material may be distributed only subject to the terms and conditions set forth in the Open Publication
License, v1.0 or later (the latest version is presently available at http://www.opencontent.org/openpub/).
Prentice Hall PTR offers excellent discounts on this book when ordered in quantity for bulk purchases
or special sales.þ For more information, please contact: U.S. Corporate and Government Sales,
1-800-382-3419, [email protected]. For sales outside of the U.S., please contact:
International Sales, 1-317-581-3793, [email protected].
Company and product names mentioned herein are the trademarks or registered trademarks
of their respective owners.
Printed in the United States of America
First Printing
ISBN 0-13-140882-8
Pearson Education LTD.
Pearson Education Australia PTY, Limited
Pearson Education Singapore, Pte. Ltd.
Pearson Education North Asia Ltd.
Pearson Education Canada, Ltd.
Pearson Educación de Mexico, S.A. de C.V.
Pearson Education—Japan
Pearson Education Malaysia, Pte. Ltd.
Contents at a Glance
I INTRODUCTION 33 Downloading Email with
Fetchmail..........................................378
1 Introduction to Webmin.......................1
34 Managing Majordomo Mailing
2 Installing Webmin................................6
Lists ................................................388
3 Securing Your Webmin Server..........14
35 The MySQL Database......................405
II SYSTEM MODULES 36 The PostgreSQL Database................428
4 Users and Groups...............................19 37 Configuring Sendmail......................448
5 Disk and Network Filesystems...........39 38 Configuring Qmail...........................476
6 NFS File Sharing................................53 39 Analyzing Log Files.........................491
7 Disk Quotas........................................60 40 The ProFTPD Server........................500
8 Partitions, RAID, and LVM...............68 41 The WU-FTPD Server......................525
9 Bootup and Shutdown........................84 42 SSH Server Configuration................544
10 Scheduled Commands........................93 43 Windows File Sharing with
11 Process Management..........................99 Samba...............................................554
12 Software Packages............................105 44 Configuring the Squid Proxy
Server................................................577
13 System Logs.....................................113
45 Filtering Email with Procmail..........605
14 Filesystem Backups..........................121
46 Creating SSL Tunnels......................615
15 Internet Services...............................129
47 Usermin Configuration.....................620
16 Network Configuration.....................144
17 Network Information Service...........154
IV CLUSTER MODULES
18 PPP Server Configuration.................165
48 Cluster Software Management.........643
19 Firewall Configuration.....................173
49 Cluster User Management................649
20 Setting the Date and Time................191
50 Cluster Webmin Configuration........660
21 Boot Loader Configuration...............195
V WEBMIN MODULES
22 Printer Administration......................205
51 Webmin Configuration.....................669
23 Voicemail Server Configuration.......215
52 Webmin Access Control...................688
24 Remote Shell Login..........................220
53 Webmin Servers...............................700
25 Running Custom Commands............224
54 Logging in Webmin..........................707
26 Webmin’s File Manager...................232
27 Perl Modules.....................................244 VI DEVELOPER’S GUIDE
28 Status Monitoring with Webmin......250 55 Webmin Module Development........710
56 Advanced Module Development......721
III SERVER MODULES
57 Inside the Scheduled Cron Jobs
29 Apache Web Server Configuration..264
Module..............................................734
30 DNS Server Configuration...............315
58 Creating Webmin Themes................741
31 CVS Server Configuration...............354
59 Inside the MSC Theme.....................747
32 DHCP Server Configuration.............361
60 The Webmin API..............................751

Contents
I INTRODUCTION Before and After Commands34
Module Access Control34
1 Introduction to Webmin 1 Other Operating Systems37
Summary38
What is Webmin?1
Who Should Use Webmin?2
5 Disk and Network Filesystems 39
How and Why Was it Developed?3
What is this Book About?4 Introduction to Filesystems39
Who Should Read this Book?4 The Disk and Network Filesystems
Conventions Used in this Book5 Module40
Acknowledgments5 Mounting an NFS Network Filesystem40
Mounting an SMBFS Windows
2 Installing Webmin 6 Networking Filesystem43
Mounting a Local ext2 or ext3 Hard Disk
Downloading Webmin for Your System6
Filesystem44
Installing the RPM Package7
Mounting a Local Windows Hard Disk
Installing the tar.gz Package8
Filesystem45
Installing the Solaris Package10
Adding Virtual Memory46
The Webmin User Interface10
Automounter Filesystems47
Uninstalling Webmin13
Editing or Removing an Existing
Summary13
Filesystem48
Listing Users of a Filesystem48
3 Securing Your Webmin Server 14
Module Access Control49
Network Security14 Configuring the Disk and Network
SSL Encryption15 Filesystems Module50
Requesting a Valid SSL Certificate17 A Comparison of Filesystem Types50
Summary18 Other Operating Systems51
Summary52
6 NFS File Sharing 53
II SYSTEM MODULES
Introduction to File Sharing with NFS53
4 Users and Groups 19 The NFS Exports Module54
Exporting a Directory54
Introduction to UNIX Users and Groups19
Editing or Deleting an NFS Export55
The Users and Groups Module20
NFS on Solaris56
Creating a New User21
NFS on BSD, MacOS X and
Editing an Existing User23
OpenServer57
Deleting a User24
NFS on Irix59
Creating a New Group25
Summary59
Editing an Existing Group26
Deleting a Group27
7 Disk Quotas 60
Viewing Recent and Current Logins27
Reading Users’ Email28 Introduction to Disk Quotas60
Creating Users from Batch Files28 The Disk Quotas Module61
Configuring the Users and Groups Enabling Quotas for a Filesystem62
Module30 Disabling Quotas for a Filesystem62
viii Contents
Setting Quotas for a User or Group63
10 Scheduled Commands 93
Copying Quotas to Multiple Users63
Setting Grace Times64 Introduction to Cron Jobs93
Setting Default Quotas for New Users65 The Scheduled Cron Jobs Module93
Other Operating Systems66 Creating a New Cron Job94
Configuring the Disk Quotas Module66 Editing a Cron Job95
Module Access Control66 Controlling Users’ Access to Cron96
Summary67 Module Access Control Options96
Configuring the Scheduled Cron Jobs
8 Partitions, RAID, and LVM 68 Module96
Introduction to Hard Disk Partitions68 Other Operating Systems97
The Scheduled Commands Module97
The Partitions on Local Disks Module69
Creating a New Scheduled Command98
Adding and Formatting a New Partition70
Creating a New Filesystem70 Summary98
Partition Labels71
Deleting or Changing a Partition72 11 Process Management 99
Module Access Control73 Introduction to Processes99
Other Operating Systems74
The Running Processes Module99
Introduction to RAID74
Viewing, Killing, or Reprioritizing a
The Linux RAID Module75
Process101
Introduction to LVM77
Searching for Processes102
The Logical Volume Management
Running a Process103
Module78
Module Access Control Options103
Creating a New Volume Group79
Other Operating Systems104
Adding and Removing a Physical
Summary104
Volume80
Creating and Deleting a Logical
12 Software Packages 105
Volume80
Resizing a Logical Volume81 Introduction to Packages105
Creating a Snapshot82
The Software Packages Module107
Summary83
Installing a New Package107
Finding and Removing a Package109
9 Bootup and Shutdown 84
Updating on Debian Linux110
Introduction to the Linux Boot Process84 Updating on Red Hat Linux111
The Bootup and Shutdown Module85 Other Operating Systems111
Configuring an Action to Start at Summary112
Bootup85
Starting and Stopping Actions86 13 System Logs 113
Adding a New Action87
Introduction to Logging113
Rebooting or Shutting Down Your
System89 The System Logs Module115
Configuring the Bootup and Shutdown Adding a New Log File115
Module89 Editing or Deleting a Log File117
Other Operating Systems89 Module Access Control118
The SysV Init Configuration Module91 Other Operating Systems119
Summary92 Summary120
Contents ix
Setting Up an NIS Master Server157
14 Filesystem Backups 121
Editing NIS Tables159
Introduction to Backups with Dump121
Securing Your NIS Server160
The Filesystem Backup Module121
Setting Up an NIS Slave Server163
Adding a New Backup122
Configuring the NIS Client and Server
Making a Backup124
Module163
Editing or Deleting a Backup125
NIS on Solaris163
Restoring a Backup125
Summary164
Configuring the Filesystem Backup
Module126
18 PPP Server Configuration 165
Other Operating Systems128
Summary128 Introduction to PPP on Linux165
Configuring a PPP Server166
15 Internet Services 129
Managing PPP Accounts169
Introduction to Internet Services129 Restricting Access by Caller ID171
The Internet Services and Protocols Module Access Control172
Module130 Summary172
Enabling an Internet Service133
Creating Your Own Internet Service133 19 Firewall Configuration 173
Creating and Editing RPC Programs135
Configuring the Internet Services and Introduction to Firewalling with
Protocols Module136 IPtables173
Other Operating Systems138 The Linux Firewall Module175
The Extended Internet Services Allowing and Denying Network
Module139 Traffic177
Enabling or Editing an Extended Internet Changing a Chain’s Default Action181
Service140
Editing Firewall Rules182
Creating an Extended Internet Service141
Creating Your Own Chain182
Editing Default Options142
Setting Up Network Address
Summary143
Translation183
Setting Up a Transparent Proxy184
16 Network Configuration 144
Setting Up Port Forwarding185
Introduction to Linux Networking144
Firewall Rule Conditions186
Viewing and Editing Network Configuring the Linux Firewall
Interfaces146 Module189
Adding a Network Interface147
Summary189
Configuring Routing149
Changing the Hostname or DNS Client
20 Setting the Date and Time 191
Settings150
Editing Host Addresses151 The System Time Module191
Module Access Control152 Changing the System Time192
Other Operating Systems153 Change the Hardware Time192
Summary153
Synchronizing Times with Another
Server193
17 Network Information Service 154
Module Access Control193
Introduction to NIS154 Other Operating Systems193
Becoming an NIS Client155 Summary194