Apache Cookbook

Apache Cookbook

Chapter 1. Installation
  Recipe 1.1. Installing from Red Hat Linux's Packages
  Section 1.2. Installing from Debian Packages
  Recipe 1.3. Installing Apache on Windows
  Recipe 1.4. Downloading the Apache Sources
  Recipe 1.5. Building Apache from the Sources
  Recipe 1.6. Installing with ApacheToolbox
  Recipe 1.7. Starting, Stopping, and Restarting Apache
  Recipe 1.8. Uninstalling Apache
  Section 1.9. Which Version of Apache to Use
  Recipe 1.10. Upgrading Using config.nice
  Recipe 1.11. Starting Apache at Boot
  Recipe 1.12. Useful configure Options
  Recipe 1.13. Finding Apache's Files

Chapter 2. Adding Common Modules
  Recipe 2.1. Installing a Generic Third-Party Module
  Recipe 2.2. Installing mod_dav on a Unixish System
  Recipe 2.3. Installing mod_dav on Windows
  Recipe 2.4. Installing mod_perl on a Unixish System
  Recipe 2.5. Installing mod_php on a Unixish System
  Recipe 2.6. Installing mod_php on Windows
  Recipe 2.7. Installing mod_ssl
  Recipe 2.8. Finding Modules Using modules.apache.org
  Recipe 2.9. Installing mod_security
  Recipe 2.10. Why Won't This Module Work?

Chapter 3. Logging
  Recipe 3.1. Getting More Details in Your Log Entries
  Recipe 3.2. Getting More Detailed Errors
  Recipe 3.3. Logging POST Contents
  Recipe 3.4. Logging a Proxied Client's IP Address
  Recipe 3.5. Logging Client MAC Addresses
  Recipe 3.6. Logging Cookies
  Recipe 3.7. Not Logging Image Requests from Local Pages
  Recipe 3.8. Rotating Logfiles at a Particular Time
  Recipe 3.9. Rotating Logs on the First of the Month
  Recipe 3.10. Logging Hostnames Instead of IP Addresses
  Recipe 3.11. Maintaining Separate Logs for Each Virtual Host
  Recipe 3.12. Logging Proxy Requests
  Recipe 3.13. Logging Errors for Virtual Hosts to Multiple Files
  Recipe 3.14. Logging Server IP Addresses
  Recipe 3.15. Logging the Referring Page
  Recipe 3.16. Logging the Name of the Browser Software
  Recipe 3.17. Logging Arbitrary Request Header Fields
  Recipe 3.18. Logging Arbitrary Response Header Fields
  Section 3.19. Logging Activity to a MySQL Database
  Section 3.20. Logging to syslog
  Section 3.21. Logging User Directories

Chapter 4. Virtual Hosts
  Recipe 4.1. Setting Up Name-Based Virtual Hosts
  Recipe 4.2. Designating One Name-Based Virtual Host as the Default
  Recipe 4.3. Setting Up Address-Based Virtual Hosts
  Recipe 4.4. Creating a Default Address-Based Virtual Host
  Recipe 4.5. Mixing Address-Based and Name-Based Virtual Hosts
  Recipe 4.6. Mass Virtual Hosting with mod_vhost_alias
  Recipe 4.7. Mass Virtual Hosting Using Rewrite Rules
  Recipe 4.8. Logging for Each Virtual Host
  Recipe 4.9. Splitting Up a Logfile
  Recipe 4.10. Port-Based Virtual Hosts
  Recipe 4.11. Displaying the Same Content on Several Addresses
  Section 4.12. Defining Virtual Hosts in a Database

Chapter 5. Aliases, Redirecting, and Rewriting
  Recipe 5.1. Mapping a URL to a Directory
  Recipe 5.2. Creating a New URL for Existing Content
  Recipe 5.3. Giving Users Their Own URLs
  Recipe 5.4. Aliasing Several URLs with a Single Directive
  Recipe 5.5. Mapping Several URLs to the Same CGI Directory
  Recipe 5.6. Creating a CGI Directory for Each User
  Recipe 5.7. Redirecting to Another Location
  Recipe 5.8. Redirecting Several URLs to the Same Destination
  Recipe 5.9. Permitting Case-Insensitive URLs
  Recipe 5.10. Showing Highlighted PHP Source without Symlinking
  Recipe 5.11. Replacing Text in Requested URLs
  Recipe 5.12. Rewriting Path Information to CGI Arguments
  Recipe 5.13. Denying Access to Unreferred Requests
  Recipe 5.14. Redirecting Unreferred Requests to an Explanation Page
  Recipe 5.15. Rewriting Based on the Query String
  Recipe 5.16. Redirecting All—or Part—of Your Server to SSL
  Recipe 5.17. Turning Directories into Hostnames
  Recipe 5.18. Redirecting All Requests to a Single Host
  Recipe 5.19. Turning Document Names into Arguments
  Recipe 5.20. Rewriting Elements between Path and Query String
  Recipe 5.21. Rewriting a Hostname to a Directory
  Recipe 5.22. Turning URL Segments into Query Arguments
  Recipe 5.23. Using AliasMatch, ScriptAliasMatch, and RedirectMatch

Chapter 6. Security
  Recipe 6.1. Using System Account Information for Web Authentication
  Recipe 6.2. Setting Up Single-Use Passwords
  Recipe 6.3. Expiring Passwords
  Recipe 6.4. Limiting Upload Size
  Recipe 6.5. Restricting Images from Being Used Off-Site
  Recipe 6.6. Requiring Both Weak and Strong Authentication
  Recipe 6.7. Managing .htpasswd Files
  Recipe 6.8. Making Password Files for Digest Authentication
  Recipe 6.9. Relaxing Security in a Subdirectory
  Recipe 6.10. Lifting Restrictions Selectively
  Recipe 6.11. Authorizing Using File Ownership
  Recipe 6.12. Storing User Credentials in a MySQL Database
  Recipe 6.13. Accessing the Authenticated Username
  Recipe 6.14. Obtaining the Password Used to Authenticate
  Recipe 6.15. Preventing Brute-Force Password Attacks
  Recipe 6.16. Using Digest Versus Basic Authentication
  Recipe 6.17. Accessing Credentials Embedded in URLs
  Recipe 6.18. Securing WebDAV
  Recipe 6.19. Enabling WebDAV Without Making Files Writable by the Web User
  Recipe 6.20. Restricting Proxy Access to Certain URLs
  Recipe 6.21. Protecting Files with a Wrapper
  Recipe 6.22. Protecting Server Files from Malicious Scripts
  Recipe 6.23. Setting Correct File Permissions
  Recipe 6.24. Running a Minimal Module Set
  Recipe 6.25. Restricting Access to Files Outside Your Web Root
  Recipe 6.26. Limiting Methods by User
  Recipe 6.27. Restricting Range Requests
  Section 6.28. Rebutting DoS Attacks with mod_evasive
  Section 6.29. Chrooting Apache with mod_security
  Section 6.30. Migrating to 2.2 Authentication
  Recipe 6.31. Blocking Worms with mod_security
  Recipe 6.32. Mixing Read-Only and Write Access to a Subversion Repository
  Recipe 6.33. Using Permanent Redirects to Obscure Forbidden URLs

Chapter 7. SSL
  Recipe 7.1. Installing SSL
  Section 7.2. Installing SSL on Windows
  Recipe 7.3. Generating Self-Signed SSL Certificates
  Recipe 7.4. Generating a Trusted CA
  Recipe 7.5. Serving a Portion of Your Site via SSL
  Recipe 7.6. Authenticating with Client Certificates
  Section 7.7. SSL Virtual Hosts
  Section 7.8. Wildcard Certificates

Chapter 8. Dynamic Content
  Recipe 8.1. Enabling a CGI Directory
  Recipe 8.2. Enabling CGI Scripts in Non-ScriptAliased Directories
  Recipe 8.3. Specifying a Default Document in a CGI Directory
  Recipe 8.4. Using Windows File Extensions to Launch CGI Programs
  Recipe 8.5. Using Extensions to Identify CGI Scripts
  Recipe 8.6. Testing that CGI Is Set Up Correctly
  Recipe 8.7. Reading Form Parameters
  Recipe 8.8. Invoking a CGI Program for Certain Content Types
  Recipe 8.9. Getting SSIs to Work
  Recipe 8.10. Displaying Last Modified Date
  Recipe 8.11. Including a Standard Header
  Recipe 8.12. Including the Output of a CGI Program
  Recipe 8.13. Running CGI Scripts as a Different User with suexec
  Recipe 8.14. Installing a mod_perl Handler from CPAN
  Recipe 8.15. Writing a mod_perl Handler
  Recipe 8.16. Enabling PHP Script Handling
  Recipe 8.17. Verifying PHP Installation
  Recipe 8.18. Parsing CGI Output for Server Side Includes
  Recipe 8.19. Parsing ScriptAlias Script Output for Server-Side Includes
  Recipe 8.20. Getting mod_perl to Handle All Perl Scripts
  Recipe 8.21. Enabling Python Script Handling

Chapter 9. Error Handling
  Recipe 9.1. Handling a Missing Host Field
  Recipe 9.2. Changing the Response Status for CGI Scripts
  Recipe 9.3. Customized Error Messages
  Recipe 9.4. Providing Error Documents in Multiple Languages
  Recipe 9.5. Redirecting Invalid URLs to Some Other Page
  Recipe 9.6. Making Internet Explorer Display Your Error Page
  Recipe 9.7. Notification on Error Conditions

Chapter 10. Proxies
  Recipe 10.1. Securing Your Proxy Server
  Recipe 10.2. Preventing Your Proxy Server from Being Used as an Open Mail Relay
  Recipe 10.3. Forwarding Requests to Another Server
  Recipe 10.4. Blocking Proxied Requests to Certain Places
  Recipe 10.5. Proxying mod_perl Content to Another Server
  Recipe 10.6. Configuring a Caching Proxy Server
  Recipe 10.7. Filtering Proxied Content
  Recipe 10.8. Requiring Authentication for a Proxied Server
  Section 10.9. Load Balancing with mod_proxy_balancer
  Section 10.10. Proxied Virtual Host
  Section 10.11. Refusing to Proxy FTP

Chapter 11. Performance
  Recipe 11.1. Determining How Much Memory You Need
  Recipe 11.2. Benchmarking Apache with ab
  Recipe 11.3. Tuning KeepAlive Settings
  Recipe 11.4. Getting a Snapshot of Your Site's Activity
  Recipe 11.5. Avoiding DNS Lookups
  Recipe 11.6. Optimizing Symbolic Links
  Recipe 11.7. Minimizing the Performance Impact of .htaccess Files
  Recipe 11.8. Disabling Content Negotiation
  Recipe 11.9. Optimizing Process Creation
  Recipe 11.10. Tuning Thread Creation
  Recipe 11.11. Caching Frequently Viewed Files
  Recipe 11.12. Distributing Load Evenly Between Several Servers
  Recipe 11.13. Caching Directory Listings
  Recipe 11.14. Speeding Up Perl CGI Programs with mod_perl
  Section 11.15. Caching Dynamic Content

Chapter 12. Directory Listings
  Recipe 12.1. Generating Directory/Folder Listings
  Section 12.2. Display a Standard Header and Footer on Directory Listings
  Recipe 12.3. Applying a Stylesheet
  Recipe 12.4. Hiding Things from the Listing
  Recipe 12.5. Searching for Certain Files in a Directory Listing
  Recipe 12.6. Sorting the List
  Section 12.7. Allowing a Client-Specified Sort Order
  Recipe 12.8. Specifying How the List Will Be Formatted
  Recipe 12.9. Allowing the Client to Specify the Formatting
  Recipe 12.10. Adding Descriptions to Files
  Recipe 12.11. Autogenerated Document Titles
  Recipe 12.12. Changing the Listing Icons
  Recipe 12.13. Listing the Directories First
  Recipe 12.14. Ordering by Version Number
  Recipe 12.15. Allowing the End User to Specify Version Sorting
  Section 12.16. Complete User Control of Output
  Section 12.17. Don't Allow the End User to Modify the Listing
  Recipe 12.18. Suppressing Certain Columns
  Section 12.19. Showing Forbidden Files
  Recipe 12.20. Aliases in Directory Listings

Chapter 13. Miscellaneous Topics
  Recipe 13.1. Placing Directives Properly
  Recipe 13.2. Renaming .htaccess Files
  Recipe 13.3. Generating Directory/Folder Listings
  Recipe 13.4. Solving the "Trailing Slash" Problem
  Recipe 13.5. Setting the Content-Type According to Browser Capability
  Recipe 13.6. Handling Missing Host: Header Fields
  Recipe 13.7. Alternate Default Document
  Recipe 13.8. Setting Up a Default "Favicon"
  Recipe 13.9. Directory Listings in ScriptAliased Directories
  Recipe 13.10. Enabling .htaccess Files
  Recipe 13.11. Converting IBM/Lotus Server-Side Includes to Apache

Appendix A. Using Regular Expressions in Apache
  Section A.1. What Directives Use Regular Expressions?

Appendix B. Troubleshooting
  Section B.1. Troubleshooting Methodology
  Section B.2. Debugging the Configuration
  Section B.3. Debugging Premature End of Script Headers
  Section B.4. Common Problems on Windows
  Section B.5. Fixing Build-Time Error Messages
  Section B.6. Getting Server-Side Includes to Work
  Section B.7. Debugging Rewrites That Result in "Not Found" Errors
  Section B.8. .htaccess Files Having No Effect
  Section B.9. Address Already in Use

The Apache Web server is a remarkable piece of software. The basic package distributed by the Apache Software Foundation is quite complete and very powerful, and a lot of effort has gone into keeping it from suffering software bloat. One facet of the package makes it especially remarkable: it includes extensibility by design. In short, if the Apache package right out of the box does not do what you want, you can generally extend it so that it does. Dozens of extensions (called modules) are included as part of the package distributed by the Apache Software Foundation. And if one of these doesn't meet your needs, with several million users out there, there is an excellent chance someone else has already done your work for you, someone who has concocted a recipe of changes or enhancements to the server that will satisfy your requirements.

This book is a collection of these recipes. Its sources include tips from the firehose of the Usenet newsgroups, the Apache FAQ, Apache-related mailing lists, mail containing "how-to" questions, questions and problems posed on IRC chat channels, and volunteered submissions.

All of the items in this book come from real-life situations, encountered either by us or by other people who have asked for our help. The topics range from basic compilation of the source code to complex problems involving the treatment of URLs that require SSL encryption.

We've collected more than a hundred different problems and their solutions, largely based on how often they occurred, and have grouped them roughly by subject as shown in Section P.1.

Primarily, these recipes are useful to webmasters who are responsible for the entire server; however, many are equally applicable to users who want to customize the behavior in their own Web directories through the use of .htaccess files.

We've written the Apache Cookbook to be a practical reference, rather than a theoretical discourse: reading it recipe by recipe, chapter by chapter, isn't going to reveal a plot ("Roy Fielding in the Library with an RFC!"[1] ). It's intended to provide point solutions to specific problems, located through the table of contents or the index.