Apache server configuration

Apache is controlled by a series of configuration files: httpd.conf, access.conf. and srm.conf (there's actually also a mime.types file, but you have to deal with that only when you're adding or removing MIME types from your server, which shouldn't be too often). The files contain instructions, called directives, that tell Apache how to run. Several companies offer GUI-based Apache front-ends, but it's easier to edit the configuration files by hand.
Remember to make back-up copies of all your Apache configuration files, in case one of the changes you make while experimenting renders the Web server inoperable.
Also, remember that configuration changes you make don't take effect until you restart Apache. If you've configured Apache to run as an inetd server, then you don't need to worry about restarting, since inetd will do that for you.
Download the reference card
As with other open-source projects, Apache users share a wealth of information on the Web. Possibly the single most useful piece of Apache-related information--apart from the code itself, of course--is a two-page guide created by Andrew Ford.
Called the Apache Quick Reference Card, it's a PDF file (also available in PostScript) generated from a database of Apache directives. There are a lot of directives, and Ford's card gives you a handy reference to them.
While this may not seem like a tip on how to run Apache, it will make your Apache configuration go much smoother because you will have the directives in an easy-to-access format.
One quick note--we found that the PDF page was a bit larger than the printable area of our printer (an HP LaserJet 8000 N). So we set the Acrobat reader to scale-to-fit and the pages printed just fine.
Use one configuration file
The typical Apache user has to maintain three different configuration files--httpd.conf, access.conf, and srm.conf. These files contain the directives to control Apache's behavior.
The tips in this story keep the configuration files separate, since it's a handy way to compartmentalize the different directives. But Apache itself doesn't care--if you have a simple enough configuration or you just want the convenience of editing a single file, then you can place all the configuration directives in one file. That one file should be httpd.conf, since it is the first configuration file that Apache interprets. You'll have to include the following directives in httpd.conf:
AccessConfig /dev/null
ResourceConfig /dev/null
That way, Apache won't cough up an error message about the missing access.conf and srm.conf files. Of course, you'll also need to copy the directives from srm.conf and access.conf into your new httpd.conf file.
Restrict access
Say you have document directories or files on your Web server that should be visible only to a select group of computers. One way to protect those pages is by using host-based authentication. In your access.conf file, you would add something like this:

order deny,allow
deny from all
allow from 10.10.64

The directive is what's called a sectional directive. It encloses a group of directives that apply to the specified directory. The Apache Quick Reference Card includes a listing of sectional directives.