After defining the Server Name, Webmaster email address, and Available
Addresses, click the Virtual Hosts tab and click
the Edit Default Settings button. The window
shown in Figure 14-3 will
appear. Configure the default settings for your Web server in this
window. If you add a virtual host, the settings you configure for the
virtual host take precedence for that virtual host. For a directive not
defined within the virtual host settings, the default value is used.
The default values for the Directory Page Search
List and Error Pages will work for
most servers. If you are unsure of these settings, do not modify
them.
The entries listed in the Directory Page Search
List define the DirectoryIndex
directive. The DirectoryIndex is the
default page served by the server when a user requests an index of a
directory by specifying a forward slash (/) at the end of the
directory name.
For example, when a user requests the page
http://your_domain/this_directory/,
they are going to get either the DirectoryIndex
page if it exists, or a server-generated directory list. The server
will try to find one of the files listed in the DirectoryIndex
directive and will return the first one it finds.
If it doesn't find any of these files and if Options
Indexes is set for that directory, the server will generate
and return a list, in HTML format, of the subdirectories and files in
the directory.
Use the Error Code section to configure Apache to
redirect the client to a local or external URL if the event of a
problem or error. This option corresponds to the ErrorDocument
directive. If a problem or error occurs when a client tries
to connect to the Apache Web server, the default action is to display
the short error message shown in the Error Code
column. To override this default configuration, select the error code
and click the Edit button. Choose
to display the default short error
message. Choose to redirect the client
to an external URL and enter a complete URL including the http:// in
the Location field. Choose
to redirect the client to an internal
URL and enter a file under the Document Root for the Web server. The
location must begin the a slash (/) and be relative to the Document
Root.
For example, to redirect a 404 Not Found error code to a Web page that
you created in a file called 404.html, copy
404.html to
DocumentRoot/errors/404.html.
In this case, DocumentRoot is the Document
Root directory that you have defined (the default is
/var/www/html). Then, choose
as the Behavior for 404 -
Not Found error code and enter
/errors/404.html as the
.
From the Default Error Page Footer menu, you can
choose one of the following options:
Show footer with email address —
Display the default Apache footer at the bottom of all error
pages along with the email address of the website maintainer
specified by the ServerAdmin
directive. Refer to the section called General Options for information
about configuring the ServerAdmin directive.
Show footer — Display just the
default Apache footer at the bottom of error pages.
No footer — Do not display a footer
at the bottom of error pages.
By default, Apache writes the transfer log to the file
/var/log/httpd/access_log and the error log to
the file /var/log/httpd/error_log.
The transfer log contains a list of all attempts to access the Web
server. It records the IP address of the client that is attempting to
connect, the date and time of the attempt, and the file on the Web
server that it is trying to retrieve. Enter the name of the path and
file in which to store this information. If the path and filename does
not start with a slash (/), the path is relative to the server root
directory as configured. This option corresponds to the TransferLog
directive.
You can configure a custom log format by checking Use custom
logging facilities and entering a custom log string in
the Custom Log String field. This configures
the LogFormat
directive. Refer to http://httpd.apache.org/docs/mod/mod_log_config.html#formats
for details on the format of this directive.
The error log contains a list of any server errors that occur. Enter
the name of the path and file in which to store this information. If
the path and filename does not start with a slash (/), the path is
relative to the server root directory as configured. This option
corresponds to the ErrorLog
directive.
Use the Log Level menu to set how verbose the
error messages in the error logs will be. It can be set (from least
verbose to most verbose) to emerg, alert, crit, error, warn, notice,
info or debug. This option corresponds to the LogLevel
directive.
The value chosen with the Reverse DNS Lookup menu
defines the HostnameLookups
directive. Choosing No Reverse Lookup
sets the value to off. Choosing Reverse Lookup
sets the value to on. Choosing Double Reverse
Lookup sets the value to double.
If you choose Reverse Lookup, your server will
automatically resolve the IP address for each connection which
requests a document from your Web server. Resolving the IP address
means that your server will make one or more connections to the DNS in
order to find out the hostname that corresponds to a particular IP
address.
If you choose Double Reverse Lookup, your server
will perform a double-reverse DNS. In other words, after a reverse
lookup is performed, a forward lookup is performed on the result. At
least one of the IP addresses in the forward lookup must match the
address from the first reverse lookup.
Generally, you should leave this option set to No Reverse
Lookup, because the DNS requests add a load to your server
and may slow it down. If your server is busy, the effects of trying
to perform these reverse lookups or double reverse lookups may be
quite noticeable.
Reverse lookups and double reverse lookups are also an issue for the
Internet as a whole. All of the individual connections made to look
up each hostname add up. Therefore, for your own Web server's
benefit, as well as for the Internet's benefit, you should leave this
option set to No Reverse Lookup.
Apache can use the mod_env module to configure the
environment variables which are passed to CGI scripts and SSI
pages. Use the Environment Variables page to
configure the directives for this Apache module.
Use the Set for CGI Scripts section to set an
environment variable that is passed to CGI scripts and SSI pages. For
example, to set the environment variable MAXNUM
to 50, click the Add
button inside the Set for CGI Script section as
shown in the section called Environment Variables and type
MAXNUM in the Environment
Variable text field and 50 in the
Value to set text field. Click
OK. The Set for CGI
Scripts section configures the SetEnv
directive.
Use the Pass to CGI Scripts section to pass the
value of an environment variable when Apache was first started to CGI
scripts. To see this environment variable, type the command
env at a shell prompt. Click the
Add button inside the Pass to CGI
Scripts section and enter the name of the environment
variable in the resulting dialog box. Click OK.
The Pass to CGI Scripts section configures the PassEnv
directive.
If you want to remove an environment variable so that the value is not
passed to CGI scripts and SSI pages, use the Unset for CGI
Scripts section. Click Add in the
Unset for CGI Scripts section, and enter the name
of the environment variable to unset. This corresponds to the UnsetEnv
directive.
Use the Directories page to configure options for
specific directories. This corresponds to the <Directory>
directive.
Click the Edit button in the top right-hand
corner to configure the Default Directory Options
for all directories that are not specified in the
Directory list below it. The options that you
choose are listed as the Options
directive within the <Directory> directive. You can configure the following
options:
ExecCGI — Allow execution of CGI
scripts. CGI scripts are not executed if this option is not
chosen.
FollowSymLinks — Allow symbolic links
to be followed.
Includes — Allow server-side includes.
IncludesNOEXEC — Allow server-side
includes, but disable the #exec and
#include commands in CGI scripts.
Indexes — Display a formatted list of
the directory's contents, if no DirectoryIndex (such as
index.html) exists in the requested
directory.
Multiview — Support
content-negotiated multiviews; this option is disabled by
default.
SymLinksIfOwnerMatch — Only follow
symbolic links if the target file or directory has the same
owner as the link.
To specify options for specific directories, click the
Add button beside the
Directory list box. The window shown in Figure 14-7 appears. Enter the directory to
configure in the Directory text field at the
bottom of the window. Select the options in the right-hand list, and
configure the Order
directive with the left-hand side options. The Order
directive controls the order in which allow and deny directives are
evaluated. In the Allow hosts from and
Deny hosts from text field, you can specify one
of the following:
Allow all hosts — Type all to allow
access to all hosts.
Partial domain name — Allow all hosts whose names match or
end with the specified string.
Full IP address — Allow access to a specific IP address.
A subnet — Such as
192.168.1.0/255.255.255.0
A network CIDR specification — such as
10.3.0.0/16
If you check the Let .htaccess files override directory
options, the configuration directives in the
.htaccess file take precedence.
