Pro Apache

891 Pages·2004·22.357 MB·English

by  Peter Wainwright (auth.)

Praise for Pro Apache, Third Edition:
'L<ls a somewhat experienced Apache user, I definitely have to say that this is by far
the best 'know all, end all' reference, bar none. Whether you are a seasoned web
server guru, or just a weekend warrior looking for some installation and configura
tion information, Pro Apache, Third Edition is definitely the book for you."
-Eric Wolf (aka Nawlej), Codewalkers (www.codewalkers.com)
Praise for Previous Editions of Pro Apache:
"Professional Apache aims to take you beyond the realm ofo n-line documentation.
The in-depth, straight to the point approach is something we can all appreciate.
It's jam packed with undocumented information and real-world experience that
everyone can learn from. The easy to understand and read explanations take the
chore out of learning and truly make this book a pleasure.... All in all,
Professional Apache is complete and informative. I recommend it."
-Tyler DeGiacomo, LinuxLookup.com (www.linuxlookup.com)
"Professional Apache will answer all the questions you may have concerning the
Apache web server. It is a very good and interesting book for anybody who needs to
get the most out oft he Apache web server. I highly recommend reading it."
-Ibrahim E Haddad, Linux Journal (www.linuxjournal.com)
"There is something in this book for everyone. Peter Wainwright shows his in-depth
knowledge ofA pache and explains it clearly using good examples."
-Richard Gale, First Monday (www.firstmonday.dk)
"Its 896 pages are divided into 12 task-based chapters sequenced logically according
to the flow of the thought processes when implementing a web server, and 10
appendices. Despite the name of this book, it does not fully concentrate on Apache
2.0 alone but covers a wide range of topics including performance, security, and
third-party modules such as FastCGI, PHP, mod_perl, mod_dav, mod_python,
mod_snake, mod_tcl, mod_ ruby, two connector modules for Tomcat (mod_jk and
mod_webapp), and mod_ssl (including OpenSSL)."
-Min Min Tsan, Apache Week (www.apacheweek.com)
Pro Apache,
Third Edition
PETER WAINWRIGHT
LLC
APRESS MEDIA,
Pro Apache, Third Edition
Copyright ©2004 by Peter Wainwright
Originally published by APRESS in 2004
All rights reserved. No part of this work may be reproduced or transmitted in any form or by
any means, electronic or mechanical, including photocopying, recording, or by any information
storage or retrieval system, without the prior written permission of the copyright owner and the
publisher.
ISBN 978-1-59059-300-4 ISBN 978-1-4302-0658-3 (eBook)
DOI 10.1007/978-1-4302-0658-3
Thademarked names may appear in this book. Rather than use a trademark symbol with every
occurrence of a trademarked name, we use the names only in an editorial fashion and to the
benefit of the trademark owner, with no intention of infringement of the trademark.
Technical Reviewer and Contributing Author: Bradley Bartram
Editorial Board: Steve Anglin, Dan Appleman, Ewan Buckingham, Gary Cornell, Tony Davis,
Jason Gilmore, Chris Mills, Dominic Shakeshaft, Jim Sumser, Karen Watterson, John Zukowski
Assistant Publisher: Grace Wong
Project Manager: Thacy Brown Collins
Development Editor: Robert J. Denn
Copy Editor: Kim Wnnpsett
Production Manager: Karl Brooks
Production Editor: Laura Cheu
Proofreader: Nancy Sixsmith
Compositor: Diana Van Winkle, Van Wmkle Design Group
Indexer: Kevin Broccoli
Cover Designer: Kurt Krames
Manufacturing Manager: Tom Debolski
The information in this book is distributed on an "as is" basis, without warranty. Although every
precaution has been taken in the preparation of this work, neither the author(s) nor Apress shall
have any liability to any person or entity with respect to any loss or damage caused or alleged to
be caused directly or indirectly by the information contained in this work. •
Contents at a Glance
About the Author ............................................................................................... xix
About the Technical Reviewer and Contributing Author. ................ xxi
Chapter 1 Apache and the Internet. ...................................................... 1
Chapter 2 Getting Started with Apache ............................................ 37
Chapter 3 Building Apache the Hay You Hant It ........................ 101
Chapter 4 Configuring Apache the Hay You Hant It .................. 155
Chapter 5 Deciding Hhat the Client Needs ................................... 231
Chapter 6 Delivering Dynamic Content ............................................ 307
Chapter 7 Hosting More Than One Heb Site .................................. .405
Chapter 8 Improving Apache,s Performance .................................. .457
Chapter 9 Monitoring Apache ................................................................ 539
Chapter 10 Securing Apache .................................................................... 597
Chapter 11 Improving Heb Server Security ..................................... 673
Chapter 12 Extending Apache .................................................................. 727
Index ...................................................................................................................... 843
iii
Contents
About the Author ............................................................................................... xix
About the Technical Reviewer and Contributing Author ................. xxi
Chapter 1. Apache and the Internet .............................................. 1
Apache: The Anatomy of a Web Server ......................................................... 1
The Apache Source ............................................................................................. 1
The Apache license ............................................................................................ 1
Support for Apache ............................................................................................. 2
How Apache Works .............................................................................................. 3
The Hypertext Transfer Protocol .................................................................. 7
lfiTP Requests and Responses .......................................................................... 7
lfiTP Headers ................................................................................................... 12
Networking and TCPIIP ...................................................................................... 13
Definitions ......................................................................................................... 13
Packets and Encapsulation. .............................................................................. 14
ACKs, NAKs, and Other Messages .................................................................... 15
The TCP/IP Network Model ............................................................................. 16
Non-IP Protocols ............................................................................................... 19
IP Addresses and Network Classes. .................................................................. 19
Special IP Addresses .......................................................................................... 20
Nettnasks and Routing ...................................................................................... 21
Web Services: Well-Known Ports ...................................................................... 23
Internet Daemon: The Networking Super Server ........................................... 24
The Future: 1Pv6 ................................................................................................ 25
Networking Tools ............................................................................................... 26
Server Hardware ................................................................................................... 29
Supported Platforms ......................................................................................... 29
Basic Server Requirements ............................................................................... 30
Memory. ............................................................................................................. 31
Network Interface. ............................................................................................. 32
Internet Connection ......................................................................................... 32
Hard Disk and Controller ................................................................................. 33
Operating System Checklist ............................................................................. 33
Redundancy and Backup .................................................................................. 34
Specific Hardware Solutions ............................................................................ 35
Get Someone Else to Do It ............................................................................. 36
Summary .................................................................................................................... 36
v
Contents
Chapter 2 Getting Started with Apache ................................. 37
Installing Apache .............................................................................................. 38
Getting Apache .................................................................................................. 38
Installing Apache from Binary Distribution. ................................................... 39
Installing Apache from Source ......................................................................... 41
Installing Apache from Prebuilt Packages ....................................................... 41
Installing Apache by Hand ............................................................................... 45
Upgrading Apache. ............................................................................................ 47
Other Issues ....................................................................................................... 49
Basic Configuration .......................................................................................... 50
Decisions ............................................................................................................ 50
Introducing the Master Configuration File ..................................................... 55
Other Basic Configuration Directives .............................................................. 56
Starting, Stopping, and Restarting the Server ................................. 57
Starting Apache on Unix ................................................................................... 58
Starting Apache on Wmdows ........................................................................... 59
Invocation Options ........................................................................................... 60
Restarting the Server ......................................................................................... 73
Stopping the Server ........................................................................................... 75
Starting the Server Automatically .................................................................... 76
Testing the Server ............................................................................................ 81
Testing with a Browser ...................................................................................... 82
Testing from the Command Line or a Terminal Program .............................. 82
Testing the Server Configuration Without Starting It ..................................... 85
Getting the Server Status from the Command Line ....................................... 86
Using Graphical Configuration Tools ....................................................... 86
Comanche. ......................................................................................................... 87
TkApache ........................................................................................................... 91
LinuxConf .......................................................................................................... 91
Webmin .............................................................................................................. 91
ApacheConf ....................................................................................................... 97
Other Configuration Tools ................................................................................ 99
Summary .................................................................................................................. 100
Chapter 3 Building Apache the Way You Want It. .......... 1o1
Why Build Apache Yourself? ......................................................................... 101
Verifying the Apache Source Archive ............................................................. 10 3
Building Apache from Source ...................................................................... 105
Configuring and Building Apache ................................................................. 106
Determining Which Modules to Include ....................................................... 111
Building Apache As a Dynamic Server .......................................................... 116
vi
Contents
Changing the Module Order (Apache 1.3) .................................................... 118
Checking the Generated Configuration ........................................................ 120
Building Apache from Source As an RPM (Apache 2) .................................. 122
Advanced Configuration ................................................................................. 124
Configuring Apache's Layout. ......................................................................... 124
Choosing a Layout Scheme ............................................................................ 124
Choosing a Multiprocessing Module (Apache 2) .......................................... 132
Rules (Apache 1.3) ........................................................................................... 135
Building Apache with suExec support ........................................................... 137
Configuring Apache's Supporting Files and Scripts ..................................... 139
Configuring Apache 2 for Cross-Platform Builds ......................................... 140
Configuring Apache for Production or Debug Builds .................................. 142
Configuring Apache for Binary Distribution. ................................................ 143
Configuring Apache's Library and Include Paths. ......................................... 143
Configuring the Build Environment ......................................................... 144
Building Modules with configure and apxs .......................................... 146
Adding Third-Party Modules with configure ................................................ 146
Building Modules with apxs ........................................................................... 148
Installing Modules with apxs .......................................................................... 150
Generating Module Templates with apxs ...................................................... 151
Overriding apxs Defaults and Using apxs in makefiles ................................ 152
Summary .................................................................................................................. 153
Chapter 4 Configuring Apache the Way You Want It ... 155
Where Apache Looks for Its Configuration .......................................... 155
Configuration File Syntax ............................................................................... 156
Configuration for Virtual Hosts ...................................................................... 156
Including Multiple Configuration Files ......................................................... 157
Per-Directory Configuration .......................................................................... 159
Conditional Configuration ............................................................................. 160
How Apache Structures Its Configuration ............................................ 163
Apache's Container Directives ........................................................................1 64
Directive Types and Locations ....................................................................... 168
Where Directives Can Go ................................................................................ 171
Container Scope and Nesting. ........................................................................ 172
How Apache Combines Containers and Their Contents ............................. 174
Legality of Directives in Containers ............................................................... 175
Options and Overrides .................................................................................... 176
Enabling and Disabling Features with Options ............................................ 176
Overriding Directives with Per-Directory Configuration ............................. 179
vii
Contents
Restricting Access with allow and deny .............................................. 182
ControllingAccess byName. .......................................................................... 183
Controlling Access by IP Address ................................................................... 184
Controlling Subnet Access by Network and Netmask .................................. 185
Controlling Access by HTIP Header ............................................................. 186
Combining Host-Based Access with User Authentication. .......................... 187
Overriding Host-Based Access ....................................................................... 188
Directory Listings .......................................................................................... 188
Enabling and Disabling Directory Indices .................................................... 189
How mod_autoindex Generates the HTML Page ......................................... 190
Controlling Which Files Are Seen with Indexlgnore ..................................... 196
Controlling the Sort Order .............................................................................. 197
Assigning Icons ................................................................................................ 199
Assigning Descriptions ................................................................................... 202
Apache's Envir.onment ...................................................................................... 203
Setting, Unsetting, and Passing Variables from the Shell ............................. 204
Setting Variables Conditionally ...................................................................... 205
Special Browser Variables ............................................................................... 207
Detecting Robots with BrowserMatch ........................................................... 209
Passing Variables to CGI ................................................................................. 209
Conditional Access Control ............................................................................ 210
Caveats with SetEnvlfvs. SetEnv. ................................................................... 210
Setting Variables with mod_rewrite ...............................................................2 11
Controlling Request and Response Headers .......................................... 211
Setting Custom Response Headers ................................................................ 213
Setting Custom Request Headers ................................................................... 215
Inserting Dynamic Values into Headers ........................................................2 16
Setting Custom Headers Conditionally .........................................................2 17
Retrieving Response Headers from Metadata Files ...................................... 217
Setting Expiry Times .......................................................................................2 19
Sending Content As-Is .................................................................................... 222
Controlling the Server Identification Header ................................. 223
Sending a Content Digest ............................................................................. 224
Handling the Neighbors ................................................................................. 225
Controlling Robots with robots. txt ................................................................2 26
Controlling Robots in HTML .......................................................................... 227
Controlling Robots with Access Control... ..................................................... 227
Attracting Robots ............................................................................................. 228
Making Sure Robots Index the Right Information ........................................ 228
Known Robots, Bad Robots, and Further Reading ....................................... 229
Sununary .................................................................................................................. 229
viii
Contents
Chapter 5 Deciding What the Client Needs ........................ 231
Content Handling and Negotiation ........................................................... 231
File Types ......................................................................................................... 232
File Encoding ................................................................................................... 236
File Languages ................................................................................................. 243
File Character Sets ........................................................................................... 245
Handling URLs with Extra Path Information ................................................ 247
Content Negotiation ....................................................................................... 248
Content Negotiation with MultiViews ........................................................... 250
File Permutations and Valid URLs with MultiViews ..................................... 256
Magic MIME Types .......................................................................................... 260
Error and Response Handling ...................................................................... 264
How Apache Handles Errors ........................................................................... 265
Error and Response Codes ............................................................................. 265
The ErrorDocument Directive ....................................................................... 266
Limitations ofErrorDocument ...................................................................... 270
Aliases and Redirection ............................................................................... 271
Aliases and ScriptAliases. ............................................................................... 271
Redirections ..................................................................................................... 273
Rewriting URLs with mod_rewrite ................................................................. 277
Server-Side Image Maps ................................................................................. 300
Matching Misspelled URLS ............................................................................ 305
Summary .................................................................................................................. 306
Chapter 6 Delivering Dynamic Content .................................. 307
Server-Side Includes ......................................................................................
30B
Enabling SSI ..................................................................................................... 309
Format of SSI Commands. .............................................................................. 311
The SSI Command Set .................................................................................... 312
SSI Variables ..................................................................................................... 312
Passing Trailing Path Information to SSis
(and Other Dynamic Documents) ................................................................. 315
Setting the Date and Error Format. ................................................................ 316
Templating with SSis ....................................................................................... 317
Caching Server-Parsed Documents ............................................................... 319
Identifying Server-Parsed Documents by Execute Permission ................... 320
CGI: The Common Gateway Interface .........................................................
321
CGI and the Environment .............................................................................. 321
Configuring Apache to Recognize CGI Scripts ............................................. 323
Setting Up a CGI Directory with ExecCGI: A Simple Way ............................ 327
'Iiiggering CGI Scripts on Events ................................................................... 330
ix