Configuration Directives in httpd.conf
The Apache HTTP Server configuration file is
/etc/httpd/conf/httpd.conf. The
httpd.conf file is well-commented and mostly
self-explanatory. Its default configuration will work for most
situations, however you should become familiar some of the more important
configuration options.
If you need to configure the Apache HTTP Server, edit
httpd.conf and then either reload, restart, or stop and
start the httpd process. How to reload, stop and
start the Apache HTTP Server is covered in the Section called Starting and Stopping httpd.
Before you edit httpd.conf, you should first copy
the original file to something like httpd.conf-old,
for example. By creating a backup, you can recover potential mistakes
made while editing the new configuration file.
If you do make a mistake and your Web server does not work correctly,
first review what you have recently edited in
httpd.conf. Make sure there are no typos.
Next look in the Web server's error log
(/var/log/httpd/error_log). The error log may not
be easy to interpret, depending on your level of experience. If you have
just experienced a problem, however, the last entries in the error log
should provide information about what happened.
The next sections provide short descriptions of the directives included
in httpd.conf. These descriptions are not
exhaustive. If you need more information, refer to the Apache
documentation provided in HTML format at
http://localhoast/manual/ or the Apache group
documentation at http://httpd.apache.org/docs-2.0/.
For more information about mod_ssl directives,
refer to the documentation included in HTML format at
http://localhost/mod/mod_ssl.html or the Apache
group mod_ssl documentation at http://httpd.apache.org/docs-2.0/mod/mod_ssl.html.
ServerRoot
The ServerRoot is the top-level directory which
contains the server's files. Both your secure and non-secure servers
are set to use a ServerRoot of
"/etc/httpd".
LockFile
LockFile sets the path to the lockfile used when
httpd is compiled with either
USE_FCNTL_SERIALIZED_ACCEPT or
USE_FLOCK_SERIALIZED_ACCEPT.
LockFile should be left at its default value.
PidFile
PidFile names the file where the server records its
process ID (pid). Your Web server is set to record its pid in
/var/run/httpd.pid.
ScoreBoardFile
The ScoreBoardFile stores internal server process
information, which is used for communication between the parent server
process and its child processes. Red Hat Linux uses shared memory to store the
ScoreBoardFile, the default of
/etc/httpd/logs/apache_runtime_status is only
used as a fallback.
Timeout
Timeout defines, in seconds, the amount of time
that your server will wait for receipts and transmissions during
communications. Specifically, Timeout defines how
long your server will wait to receive a GET request, how long it will
wait to receive TCP packets on a POST or PUT request and how long it
will wait between ACKs responding to TCP packets.
Timeout is set to 300 seconds, which is appropriate
for most situations.
KeepAlive
KeepAlive sets whether your server will allow more
than one request per connection (in other words, it will allow
persistent connections). KeepAlive can be used to
prevent any one client from consuming too much of the server's
resources.
By default Keepalive is set to off. If Keepalive is set to on and the
server becomes very busy, the server can quickly spawn the maximum
number of child processes. In this situation, the server will slow
down significantly. If Keepalive is enabled, it is a good idea to set
the the KeepAliveTimeout low (see the Section called KeepAliveTimeout) and monitor the servers
/var/log/httpd/error_log. This log will report
when the server is running out of child processes.
MaxKeepAliveRequests
This directive sets the maximum number of requests allowed per
persistent connection. The Apache Group recommends a high setting,
which will improve your server's performance.
MaxKeepAliveRequests is set to
100 by default, which should be appropriate for
most situations.
KeepAliveTimeout
KeepAliveTimeout sets the number of seconds your
server will wait after a request has been served before it closes the
connection. Once the server receives a request, the
Timeout directive applies instead.
MinSpareServers and
MaxSpareServers
The Apache HTTP Server dynamically adapts to the perceived load by
maintaining an appropriate number of spare server processes based on
the traffic. The server checks the number of servers waiting for a
request and kills some if there are more than
MaxSpareServers or creates some if the number of
servers is less than MinSpareServers.
Your server's default MinSpareServers is
5; your server's default
MaxSpareServers is 20. These
default settings should be appropriate in most situations. You should
not increase the MinSpareServers to a large
number. Doing so will create a heavy processing load on your server
even when traffic is light.
StartServers
StartServers sets how many server processes are
created upon startup. Since your Web server dynamically kills and
creates server processes based on traffic load, you will not need to
change this parameter. Your Web server is set to start eight server
processes at startup.
MaxClients
MaxClients sets a limit on the total number of
server processes, or simultaneously connected clients, that can run
at one time. You should keep MaxClients at a high
number (your server's default is set to 150), because no one else will
be allowed to connect once that number of simultaneously connected
clients is reached. You can not set MaxClients to
higher than 256 without recompiling Apache. The main reason for
having MaxClients is to keep a runaway Web server from
crashing your operating system.
MaxRequestsPerChild
MaxRequestsPerChild sets the total number of
requests each child server process serves before the child dies. The
main reason for setting MaxRequestsPerChild is to
avoid long-lived process induced memory leaks. The default
MaxRequestsPerChild for your server is
1000.
Listen
The Listen command identifies the ports on which
your Web server will accept incoming requests. Your Web server is set
to listen to port 80 for non-secure Web communications and (in the
virtual host tags that define the secure server) to port 443 for
secure Web communications.
If you set the Apache HTTP Server to listen to a port under 1024, you must be root to
start it. For port 1024 and above, httpd can be
started as a regular user.
Listen can also be used to specify particular IP
addresses over which the server will accept connections.
Include
Include allows other configuration files to be
included at runtime.
The path to these configuration files can be absolute or relative to
the ServerRoot.
 | Important |
|---|
| | In order for the server to use individually packaged modules, such
as mod_ssl, mod_perl, and
php, the following directive must be in
Section 1: Global Environment of
http.conf:
|
IfDefine
The <IfDefine> and
</IfDefine> tags surround configuration
directives that are applied if the "test" stated in the
<IfDefine> tag is true. The directives are
ignored if the test is false.
The test in the <IfDefine> tags is a
parameter name (for example, HAVE_PERL). If the
parameter is defined, meaning that it is provided as an argument to
the server's start-up command, then the test is true. In this case,
when your Web server is started, the test is true and the directives
contained in the IfDefine tags are applied.
By default, <IfDefine HAVE_SSL> tags surround
the virtual host tags for your secure server. <IfDefine
HAVE_SSL> tags also surround the
LoadModule and AddModule
directives for the ssl_module.
ExtendedStatus
The ExtendedStatus directives controls whether
Apache generates basic (off) or detailed server
status information (on), when the
server-status handler is
called. Server-status is called using
Location tags. More information on calling
server-status is included in the Section called Location.
User
The User directive sets the userid used by the
server to answer requests. User's setting
determines the server's access. Any files inaccessible to this user
will also be inaccessible to your website's visitors. The default for
User is apache.
The User should only have privileges so that it can
access files which are supposed to be visible to the outside world.
The User is also the owner of any CGI processes
spawned by the server. The User should not be
allowed to execute any code which is not intended to be in response to
HTTP requests.
 | Note |
|---|
| | For security reasons, the Apache HTTP Server will refuse to run as User
root. Using root as the User will
create large security holes for your Web server.
|
The parent httpd process first runs as root during
normal operations but is then immediately handed off to the apache
user. The server must start as root because it needs to bind to a
port below 1024 (the default port for secure Web communications is
port 443; the default port for non-secure Web communications is port
80). Ports below 1024 are reserved for system use, so they can not be
used by anyone but root. Once the server has attached itself to its
port, however, it hands the process off to the User
before it accepts any connection requests.
Group
The Group directive is similar to the
User. The Group sets the group
under which the server will answer requests. The default
Group is apache.
ServerAdmin
ServerAdmin should be the email address of the Web
server's administrator. This email address will show up in error
messages on server-generated webpages, so users can report a problem
by sending email to the server
administrator. ServerAdmin is set by default to
root@localhost.
Typically, a good way to set up ServerAdmin is to
set it to webmaster@your_domain.com. Then alias
webmaster to the person responsible for the Web
server in /etc/aliases. Finally, run
/usr/bin/newaliases to add the new alias.
ServerName
Use ServerName to set a hostname and port number
(matching the Listen directive) for the server. The
ServerName does not need to match the machine's actual hostname. For
example, you might want to use www.your_domain.com when your server's
real name is actually foo.your_domain.com. Note that the
ServerName must be a valid Domain Name Service
(DNS) name that you have the right to use — do not just make something
up. For example:
ServerName www.your_domain.com:80 |
If you do specify a ServerName, be sure its IP
address and server name pair are included in your
/etc/hosts file.
DocumentRoot
The DocumentRoot is the directory which contains
most of the HTML files which will be served in response to requests.
The default DocumentRoot for both the non-secure
and secure Web servers is the /var/www/html
directory. For example, the server might receive a request for the
following document:
http://your_domain/foo.html |
The server will look for the following file in the default directory:
If you want to change the DocumentRoot so that it
is not shared by the secure and the non-secure Web servers, see the Section called Using Virtual Hosts.
Directory
<Directory /path/to/directory> and
</Directory> tags are used to enclose a group
of configuration directives that are meant to apply only to that
directory and all of its subdirectories. Any directive which is
applicable to a directory may be used within
<Directory>
tags. <File> tags can be used in the same
way, to apply to a specific file or files.
By default, very restrictive parameters are applied to the root
directory, using the Options (see the Section called Options) and
AllowOverride (see the Section called AllowOverride) directives. Under this
configuration, any directory on your system which needs more
permissive settings has to be explicitly given those settings.
Using Directory tags, the
DocumentRoot is defined to have less rigid
parameters, so that HTTP requests can be served from it.
The cgi-bin directory is set up to allow the
execution of CGI scripts, with the ExecCGI
option. If you need to execute a CGI script in another directory, you
will need to set ExecCGI for that directory. For
example, if your cgi-bin is
/var/www/cgi-bin, but you want to execute CGI
scripts from within /home/my_cgi_directory, add an
ExecCGI directive to a set of
Directory directives like the following to your
httpd.conf file:
<Directory /home/my_cgi_directory>
Options +ExecCGI
</Directory> |
To allow CGI script execution in
/home/my_cgi_directory, you will need to take a
few extra steps besides setting ExecCGI. You will
also need to have the AddHandler directive
uncommented to identify files with the .cgi
extension as CGI scripts. See the Section called AddHandler
for instructions on setting AddHandler. Permissions
for CGI scripts, and the entire path to the scripts, must be set to
0755.
Options
The Options directive controls which server
features are available in a particular directory. For example, under
the restrictive parameters specified for the root directory,
Options is set to only
FollowSymLinks. No features are enabled, except
that the server is allowed to follow symbolic links in the root
directory.
By default, in your DocumentRoot directory,
Options is set to include
Indexes, Includes and
FollowSymLinks. Indexes permits
the server to generate a directory listing for a directory if no
DirectoryIndex (for example,
index.html) is
specified. Includes means that server-side includes
are permitted. FollowSymLinks allows the server to
follow symbolic links in that directory.
You will also need to include Options statements for
directories within virtual hosts directives, if you want your virtual
hosts to recognize those Options.
For example, server side includes are already enabled inside the
/var/www/html directory, because of the
Options Includes line within the
<Directory "/var/www/html"> directives
section. However, if you want a virtual host to recognize server
side includes,
you will need to include a section like the following within your
virtual host's tags:
<Directory /var/www/html>
Options Includes
</Directory> |
AllowOverride
The AllowOverride directive sets whether or not any
Options can be overridden by the declarations in an
.htaccess file. By default, both the root
directory and the DocumentRoot are set to allow no
.htaccess overrides.
Order
The Order directive simply controls the order in
which allow and deny directives
are evaluated. Your server is configured to evaluate the
Allow directives before the Deny
directives for your DocumentRoot directory.
Allow
Allow specifies which requester can access a given
directory. The requester can be all, a domain
name, an IP address, a partial IP address, a network/netmask pair, and
so on. Your DocumentRoot directory is configured
to Allow requests from all
meaning everyone has access.
Deny
Deny works just like Allow, but
you are specifying who is denied access. Your
DocumentRoot is not configured to
Deny requests from anyone by default.
UserDir
UserDir is the name of the subdirectory within each
user's home directory where they should place personal HTML files
which are to be served by the Web server.
By default, the subdirectory is public_html. For
example, the server might receive the following request:
http://your_domain/~username/foo.html |
The server would look for the file:
/home/username/public_html/foo.html |
In the above example, /home/username/ is the
user's home directory (note that the default path to users' home
directories may be different on your system).
Make sure that the permissions on the users' home directories are set
correctly. Users' home directories must be set to 0711. The read (r)
and execute (x) bits must be set on the users'
public_html directories (0755 will also work).
Files that will be served in users' public_html
directories must be set to at least 0644.
This directive is set to disable by default.
DirectoryIndex
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.
When a user requests the page
http://your_domain/this_directory/,
they will get either the DirectoryIndex
page if it exists, or a server-generated directory list. The default
for DirectoryIndex is
index.html index.htm
index.shtml index.php
index.php4 index.php3
index.cgi. The server will try to find any one of
these files, and will return the first one it finds. If it does not
find any of these files and Options Indexes is set
for that directory, the server will generate and return a listing, in
HTML format, of the subdirectories and files in the directory.
AccessFileName
AccessFileName names the file which the server
should use for access control information in each directory. By
default, your Web server is set to use .htaccess,
if it exists, for access control information in each directory.
Immediately after the AccessFileName directive, a
set of Files tags apply access control to any file
beginning with a .ht. These directives deny Web
access to any .htaccess files (or other files
which begin with .ht) for security reasons.
CacheNegotiatedDocs
By default, your Web server asks proxy servers not to cache any
documents which were negotiated on the basis of content (that is, they
may change over time or because of the input from the requester). If
you set CacheNegotiatedDocs to on,
you are disabling that function and proxy servers will be allowed to
cache documents.
UseCanonicalName
UseCanonicalName is set by default to
on. UseCanonicalName allows the
server to construct an URL that references itself, using
ServerName and Port. When the
server refers to itself in response to requests from clients, it uses
this URL. If you set UseCanonicalName to
off, the server will instead use the value that
came in the request from the client to refer to itself.
TypesConfig
TypesConfig names the file which sets the default
list of MIME type mappings (filename extensions to content types).
The default TypesConfig file is
/etc/mime.types. Instead of editing
/etc/mime.types, the recommended way to add MIME
type mappings is to use the AddType directive.
For more information about AddType, refer to
the Section called AddType.
DefaultType
DefaultType sets a default content type for the Web
server to use for documents whose MIME types can not be determined.
Your Web server defaults to assume a plain text content type for any
file with an indeterminate content type.
IfModule
<IfModule> and
</IfModule> tags surround directives that are
conditional. The directives contained within the
IfModule tags are processed under one of two
conditions. The directives are processed if the module contained
within the starting <IfModule> tag is loaded
in to httpd. Or, if an "!" (an exclamation point) is
included before the module name, the directives are processed only if
the module in the starting <IfModule> tag is
not compiled in.
The mod_mime_magic.c file is included in these
IfModule tags. The mod_mime_magic module can be
compared to the UNIX file command, which looks at a
few bytes of a file's contents, then uses "magic numbers" and other
hints in order to figure out the MIME type of the file.
If the mod_mime_magic module is compiled in to the Apache HTTP Server, these
IfModule tags tell the mod_mime_magic module where
the hints definition file is: /usr/share/magic in this
case.
The mod_mime_magic module is not compiled in by default. If you would
like to use it, see the Section called Adding Modules to Your Server, for
instructions on how to add modules to your server.
HostnameLookups
HostnameLookups can be set to
on, off or
double. If you allow
HostnameLookups (by setting it to
on), 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 set
HostnameLookups to double, 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 HostnameLookups set to
off, because the DNS requests add a load to your
server and may slow it down. If your server is busy, the effects of
HostnameLookups will be noticeable.
HostnameLookups 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 good of the Internet as a whole, you should leave
HostnameLookups set to off.
If you like to see the hostnames in your log files, consider
running one of the many log analyzer tools that perform the DNS lookups
more efficiently and in bulk when you come to rotate your log
files.
ErrorLog
ErrorLog names the file where server errors are
logged. As this directive indicates, the error log file for your Web
server is /var/log/httpd/error_log.
The error log is a good place to look if your Web server generates any
errors or fails, and you are not sure what happened.
LogLevel
LogLevel sets how verbose the error messages in the
error logs will be. LogLevel can be set (from
least verbose to most verbose) to emerg,
alert, crit,
error, warn,
notice, info or
debug. The default LogLevel is
warn.
LogFormat
The LogFormat directives in your
httpd.conf file set up a format for the messages
in your access log. The actual LogFormat used will
depend on the settings given in the CustomLog
directive (see the Section called CustomLog).
CustomLog
CustomLog identifies the log file and the log file
format. In your Web server's default configuration,
CustomLog defines the log file in which accesses to
your Web server are recorded:
/var/log/httpd/access_log. You will need to know
the location of this file if you want to generate any access-based
server performance statistics for your Web server.
CustomLog also sets the log file format
to combined. The common logfile format looks like this:
remotehost rfc931 authuser [date] "request" status bytes referer user-agent |
- remotehost
The remote hostname. If the hostname is not available from DNS,
or if HostnameLookups is set to
Off, then
remotehost
will be the IP address of the remote host.
- rfc931
Not used. You will see a - in the log file in
its place.
- authuser
If authentication was required, this is the username with which
the user identified herself. Usually, this is not used, so
you will see a - in its place.
- [date]
The date and time of the request.
- "request"
The request string exactly as it came from the browser or
client.
- status
The HTTP status code which was returned to the browser or
client.
- bytes
The size of the document.
- referer
This can give the URL of the webpage which linked to the
the current request.
- user-agent
This gives the name of the browser or client making the
request.
ServerSignature
The ServerSignature directive adds a line
containing the Apache server version and the
ServerName of the serving host to any
server-generated documents (for example, error messages sent back to
clients). ServerSignature is set to
on by default. You can change it to
off, so no signature line will be added, or you can
change it to EMail. EMail will
add a mailto:ServerAdmin HTML tag to the signature
line.
Alias
The Alias setting allows directories to be outside
the DocumentRoot directory and yet still accessible
to the Web server. Any URL ending in the alias will automatically
resolve to the alias' path. By default, one alias is already set up.
An icons directory can be accessed by the Web
server, but the directory is not in the
DocumentRoot. The icons
directory, an alias, is actually
/var/www/icons/, not
/var/www/html/icons/.
ScriptAlias
The ScriptAlias setting defines where CGI scripts
(or other types of scripts) can be found. Generally, you do not want
to leave CGI scripts within the DocumentRoot. If
CGI scripts are in DocumentRoot, they could
potentially be viewed as text documents. Even if you do not care if
people can see and then use your CGI scripts, revealing how they
work creates opportunities for unscrupulous people to exploit any
security holes in the script and may create a security risk for your
server. By default, the cgi-bin directory is a
ScriptAlias of /cgi-bin/ and
is actually located in /var/www/cgi-bin/.
Your /var/www/cgi-bin directory has
Options ExecCGI set, meaning that execution of CGI
scripts is permitted within that directory.
See the Section called AddHandler and the Section called Directory for instructions on how to
execute CGI scripts in directories other than the
cgi-bin.
Redirect
When a webpage is moved, Redirect can be used to
map the old URL to a new URL. The format is as follows:
Redirect /path/foo.html http://new_domain/path/foo.html |
So, if an HTTP request is received for a page which used to be found
at
http://your_domain/path/foo.html,
the server will send back the new URL
(http://new_domain/path/foo.html)
to the client, which should attempt to fetch the document from the new
URL.
For more advanced Redirection you can use the
mod_rewrite module included with the server.
IndexOptions
IndexOptions controls the appearance of server
generated directing listings, by adding icons, file descriptions, and
so on. If Options Indexes is set (see the Section called Options), your Web server may generate a
directory listening when your Web server receives an HTTP request like
the following:
http://your_domain/this_directory/
First, your Web server looks in that directory for a file from the
list after the DirectoryIndex directive (usually,
index.html). If your Web server does not find one
of those files, it creates an HTML directory listing of the
subdirectories and files in the directory. You can modify the
appearance of this directory listing using certain directives in
httpd.conf, including
IndexOptions.
Your default configuration sets FancyIndexing on.
If FancyIndexing is turned on, clicking on the
column headers in the directory listing will sort the order of the
display by that header. Another click on the same header will switch
from ascending to descending order and
back. FancyIndexing also shows different icons for
different files, depending upon file extensions. If you use the
AddDescription directive and turn
FancyIndexing on, then a short description of a
file will be included in the server generated directory listing.
IndexOptions has a number of other parameters which
can be set to control the appearance of server generated directories.
Parameters include IconHeight and
IconWidth, to make the server include HTML
HEIGHT and WIDTH tags for the
icons in server generated webpages; IconsAreLinks,
for making the icons act as part of the HTML link anchor along with
the filename and others.
AddIconByEncoding
This directive names icons which will be displayed by files with
MIME encoding, in server generated directory listings. For example,
by default, your Web server shows the
compressed.gif icon next to MIME encoded
x-compress and x-gzip files in server generated directory listings.
AddIconByType
This directive names icons which will be displayed next to files with
MIME types in server generated directory listings. For example, your
server is set to show the icon text.gif next to
files with a mime-type of "text," in server generated directory
listings.
AddIcon
AddIcon tells the server which icon to show in
server generated directory listings for certain file types or for
files with certain extensions. For example, your Web server is set to
show the icon binary.gif for files with
.bin or .exe extensions.
DefaultIcon
DefaultIcon names the icon to show in server
generated directory listings for files which have no other icon
specified. The unknown.gif image file is the
DefaultIcon for those files by default.
AddDescription
You can use AddDescription to show text that you
specify for certain files, in server generated directory listings
(you will also need to enable FancyIndexing as an
IndexOptions). You can name specific files,
wildcard expressions or file extensions to specify the files which
this directive should apply to. For example, you could use the
following line:
AddDescription "A file that ends in .ni" .ni |
In server generated directory listings, all files with extensions of
.ni would have the description A file
that ends in .ni after the filename. Note that you will also
need FancyIndexing turned on.
ReadmeName
ReadmeName names the file which (if it exists in
the directory) will be appended to the end of server generated
directory listings. The Web server will first try to include the file
as an HTML document and then try to include it as plain text. By
default, ReadmeName is set to
README.
HeaderName
HeaderName names the file which (if it exists in
the directory) will be prepended to the start of server generated
directory listings. Like ReadmeName, the server
will try to include it as an HTML document if possible, or in
plain text if not.
IndexIgnore
IndexIgnore lists file extensions, partial
filenames, wildcard expressions or full filenames. The Web server
will not include any files which match any of those parameters in
server generated directory listings.
AddEncoding
AddEncoding names filename extensions which should
specify a particular encoding type. AddEncoding
can also be used to instruct some browsers (not all) to uncompress
certain files as they are downloaded.
AddLanguage
AddLanguage associates filename extensions with
specific content languages. This directive is mostly useful for
content negotiation, when the server returns one of several documents
based on the client's language preference as set in their browser.
LanguagePriority
LanguagePriority allows you to set precedence for
different languages in which to serve files, which will be in effect
if the client expressed no preference for language in their browser.
AddType
Use the AddType directive to define MIME type and
file extension pairs. For example, if you are using PHP4, your Web
server is using the AddType directive to make your
Web server recognize files with PHP extensions
(.php4, .php3
.phtml .php) as PHP MIME
types. The following directive tells the Apache HTTP Server to
recognize the .shtml file extension:
AddType text/html .shtml
AddHandler server-parsed .shtml |
You will need to include the above line within the virtual host tags for
any virtual hosts which should allow server side includes.
AddHandler
AddHandler maps file extensions to specific
handlers. For example, the cgi-script handler can
be used matched with the extension .cgi to
automatically treat a file ending with .cgi as a
CGI script. This will work, even for files outside of the
ScriptAlias directory, as long as you follow the
instructions provided here.
You have a CGI AddHandler line in your
httpd.conf file:
AddHandler cgi-script .cgi |
You will have to uncomment the line. Then Apache will execute CGI
scripts for files ending in .cgi, even if they
are outside of the ScriptAlias, which is set by
default to locate your /cgi-bin/ directory in
/var/www/cgi-bin/.
You will also need to set ExecCGI as an
Options for any directory containing a CGI
script. See the Section called Directory for more
information about setting ExecCGI for a
directory. Additionally, you will need to make sure the permissions are
set correctly for the CGI scripts and the directories containing CGI
scripts. CGI scripts and the entire directory path to the scripts
must be set to 0755.
You will need to add the same AddHandler line to your
VirtualHost setup, if you are using virtual hosts
and you want them to also recognize CGI scripts outside the
ScriptAlias.
In addition to CGI scripts, your Web server also uses
AddHandler to process server-parsed HTML and
imagemap files.
Action
Action allows you to specify a MIME content type
and CGI script pair, so that whenever a file of that media type is
requested, a particular CGI script will be executed.
MetaDir
MetaDir specifies the name of a directory where
your Web server should look for files containing meta information
(extra HTTP headers) to include when serving documents.
MetaSuffix
MetaSuffix specifies the filename suffix for the
file that contains meta information (extra HTTP headers), which should
be located in the MetaDir directory.
ErrorDocument
By default, in the event of a problem or error, your Web server
outputs a simple and usually cryptic error message back to the
requesting client. Instead of using the default, you can use
ErrorDocument to configure your Web server so that
it outputs a customized message or redirects the client to a local or
external URL. The ErrorDocument directive simply
associates a HTTP response code with a message or a URL which will be
sent back to the client.
| Important |
|---|
| | You must enclose the error message in a pair of
double quotes for it to be valid.
|
BrowserMatch
The BrowserMatch directive allows your server to
define environment variables and take appropriate actions based on the
User-Agent HTTP header field — which identifies the client's
browser. By default, your Web server uses
BrowserMatch to deny connections to specific
browsers with known problems and also to disable keepalives and HTTP
header flushes for browsers that are known to have problems with those
actions.
Location
<Location> and
</Location> tags allow you to specify access
control based on URL.
If you want to allow people connecting from your domain to see server
status reports, you should uncomment the next section of directives:
#<Location /server-status>
# SetHandler server-status
# Order deny,allow
# Deny from all
# Allow from .your_domain.com
#</Location> |
You must replace .your_domain.com with your second
level domain name.
If you want to provide server configuration reports (including
installed modules and configuration directives) to requests from
inside your domain, you will need to uncomment the following lines:
#<Location /server-info>
# SetHandler server-info
# Order deny,allow
# Deny from all
# Allow from .your_domain.com
#</Location> |
Again, you must fill in .your_domain.com.
ProxyRequests
If you uncomment the IfModule tags surrounding the
ProxyRequests directives, your Apache HTTP Server will
also function as a proxy server. You will also need to load the
mod_proxy module. For instructions on how to load
in modules, see the Section called Adding Modules to Your Server.
ProxyVia
The ProxyVia command controls whether or not an
HTTP Via: header line is sent along with requests or replies which go
through the Apache proxy server. The Via: header will show the
hostname if ProxyVia is set to
On, the hostname and the Apache HTTP Server version for
Full, any Via: lines will be passed along unchanged
for Off, and Via: lines will be removed for
Block.
Cache Directives
A number of cache directives are commented out in the proxy
IfModule tags mentioned above. If you are using
the proxy server functionality and you want to also enable the proxy
cache, you should uncomment the cache directives as described. The
default settings for your cache directives should be appropriate for
most configurations.
CacheRoot sets the name of the directory which will
contain cached files. The default CacheRoot is
/var/cache/httpd.
CacheSize sets how much space the cache can use, in
KB. The default CacheSize is 5
KB.
CacheGcInterval sets a number of hours. After that
number of hours, files in the cache will be deleted if the cache is
using more space than allowed by CacheSize. The
default for CacheGcInterval is four hours.
Cached HTML documents will be retained (without a reload from the
originating Web server) in the cache for a maximum number of hours set
by CacheMaxExpire. The default is
24 hours.
The CacheLastModifiedFactor affects the creation of
an expiry (expiration) date for a document which did not come from its
originating server with its own expiry set. The default
CacheLastModifiedFactor is set to
0.1, meaning that the expiry date for such
documents equals one-tenth of the amount of time since the document
was last modified.
CacheDefaultExpire is the expiry time in hours for
a document that was received using a protocol that does not support
expiry times. The default is set to one hour.
Any document that is retrieved from a host or domain that matches
one set in NoCache will not be cached. If you know
of hosts or domains from which you do not want to cache documents,
uncomment NoCache and set their domains or
hostnames here.
NameVirtualHost
You will need to use the NameVirtualHost directive
for the IP address and port number, if necessary, of any name-based
virtual hosts you are setting up. The name-based virtual hosts
configuration is used when you want to set up different virtual hosts
for different domains, but you do not have or do not want to use
different IP addresses for all of the different domain names for which
your Web server serves documents.
| Note |
|---|
| | Any name-based virtual hosts you set up will only work with
non-secure HTTP connections as you cannot use name-based virtual
hosts with a secure server. If you need to use virtual hosts with a
secure server, you will need to use IP address-based virtual hosts.
|
If you are using name-based virtual hosts, uncomment the
NameVirtualHost configuration directive and add the
correct IP address for your server after
NameVirtualHost. Then add more information about
the different domains using the VirtualHost tags
which surround the ServerName for each virtual
host, plus any other configuration directives which are only
applicable to that virtual host.
VirtualHost
<VirtualHost> and
</VirtualHost> tags surround any
configuration directives which are intended to apply to a virtual
host. Most configuration directives can be used within virtual host
tags, and then they only apply to that particular virtual host.
A set of commented out VirtualHost tags surround
some example configuration directives and placeholders for the
information you would need to fill in to set up a virtual host. Please
see the Section called Using Virtual Hosts, for more
information about virtual hosts.
| Note |
|---|
| | All SSL virtual hosts contexts have been moved into the file
/etc/httpd/conf.d/ssl.conf.
|
SetEnvIf
The Apache configuration directive SetEnvIf can be
used to set environment variables based on headers in the request. In
the supplied httpd.conf file, it is used to
disable HTTP keepalive and to allow SSL to close the connection
without a close notify alert from the client browser. This setting is
necessary for certain browsers that do not reliably shut down the SSL
connection.
SSL Configuration Directives
The SSL directives in /etc/httpd/conf.d/ssl.conf
file can be configured to enable secure Web communications using SSL and
TLS.
For more information on SSL directives, please point your browser to
http://localhost/manual/mod/mod_ssl.html or the Apache
group mod_ssl documentation at http://httpd.apache.org/docs-2.0/mod/mod_ssl.html.
For information about setting up an Apache HTTP Secure Server see the
chapter titled Apache HTTP Secure Server
Configuration in the Official Red Hat Linux Customization Guide.
| Note |
|---|
| | Do not modify your SSL directives unless you are absolutely sure about
what you are doing. In most cases, the SSL directives are configured
appropriately as installed.
|
