| SUSE LINUX Documentation Chapter 46. The Apache Web Server / 46.3. Configuration | ||||
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 | 46.2. Installation | 46.4. Virtual Hosts |  | |
| SUSE LINUX Documentation Chapter 46. The Apache Web Server / 46.3. Configuration | ||||
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| 46.2. Installation | 46.4. Virtual Hosts | | |
Apache in SUSE Linux can be configured in two different ways: with YaST or manually. Manual configuration offers a higher level of detail, but lacks the convenience of the YaST GUI.
![[Important]](admon/important.png) | Configuration Changes |
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Changes to some configuration values for Apache only take effect after Apache is restarted. This happens automatically when finishing the configuration using YaST with checked for the . Manual restart is described in Section 46.3.3, “Activating, Starting, and Stopping Apache”. Most configuration changes only require a reload with rcapache2 reload. | |
With YaST, you can turn a host in your network into a Web server. To configure such a server, start YaST and select +. When starting the module for the first time, the HTTP Server Wizard starts, prompting you to make just a few basic decisions concerning administration of the server.
The HTTP Server Wizard consists of five steps or dialogs. In the last step of the dialog, you are given the opportunity to enter the expert configuration mode to make even more specific settings.
Here, specify the network interfaces and ports Apache uses to listen for incoming requests. You can select any combination of existing network interfaces and their respective IP addresses. Ports from all three ranges (well-known ports, registered ports, and dynamic or private ports) that are not reserved by other services can be used.
The default setting is to listen on all network interfaces (IP addresses) on port 80. When the firewall is enabled, you can check whether to enable Apache ports on the firewell.
Check to open the ports
in the firewall that the Web server listens on. This is necessary to make the
Web server available on the network, which can be a LAN, WAN, or the
public Internet. Keeping the Listen port closed
is useful in test situations where no external access to the Web server is
necessary. If you are satisfied with the default settings or if
you have made any changes, click to continue with
configuration.
The SUSE Linux Apache package comes with a wide variety of Apache modules. Modules extend Apache's functionality and are available for a wide range of tasks. The configuration option allows for the loading and unloading of various Apache modules at when the server is started. For a more detailed explanation of modules, refer to Section 46.5, “Apache Modules”. Click to continue.
This option pertains to the default Web server. As
explained in Section 46.4, “Virtual Hosts”, Apache can
serve multiple domains from a single physical machine. The
first declared domain (or
VirtualHost) in the configuraton file is commonly
referred to as the Default Host. To edit the host
settings, choose
the appropriate entry in the table then click .
To add a new host, click . To delete a host,
select it and click .
In this step, you can decide to add an SSL (secure sockets layer) option and value to the host settings. You can read more about this in Section 46.3.1.3, “Adding SSL Support”.
Here is list of the default settings of the server:
As described in Section 46.2.3.4, “Document Root”,
/srv/www/htdocs is the default location from which
Apache serves Web pages.
/srv/www/htdocs is the location of the Web pages.
With the help of Alias directives, URLs can be mapped
to physical file system locations. This means that a certain path even
outside the Document Root in the file
system can be accessed via a URL aliasing that path.
The default SUSE Linux Alias /icons
points to /usr/share/apache2/icons for the Apache
icons displayed in the directory index view.
/usr/shareapache2/icons is the location of the
Alias directory.
Similar to the Alias directive, the ScriptAlias
directive maps a URL to a file system location. The difference is that
ScriptAlias designates the target directory as a CGI location,
meaning that CGI scripts should be executed in that location.
/srv/www/cgi-bin is the location of the ScriptAlias
directory.
/etc/apache2/conf.d/*.conf is the directory containing
the configuration files that come with certain packages.
/etc/apache2/conf.d/apache2-manual?conf is the
directory containing all apache2-manual
configuration files.
This option refers to Section 46.4, “Virtual Hosts”.
lets a
VirtualHost answer on a request to its server name
(see Section 46.4.1, “Name-Based Virtual Hosts”).
makes Apache select the requested host by the HTTP header information the client sends. See Section 46.4.2, “IP-Based Virtual Hosts” for more details on IP-based virtual hosts.
This specifies the default URL used by clients to contact the Web
server. Usa a FQDN (see Domain) to
reach the Web server at http://
or its IP address.
FQDN
Provide the Web server administrator's e-mail address for .
After finishing with the step, click to continue with the configuration dialog.
In this step, the wizard displays a list of already configured virtual hosts (see Section 46.4, “Virtual Hosts”). One of the hosts is marked as default (with an asterisk next to the server name). To set a default host, select the server and click .
To add a host, click and a dialog appears in which to
enter basic information about the host. includes the server name, server contents
root, and administrator
e-mail. The help text in the left frame of the window explains each of these
items in detail. is used
to determine how a host is identified. You can specify whether to determine
a request server from HTTP headers or by server IP address by selecting the
respective option. The other possibility is to determine the virtual host by
the IP address used by the client when connecting to the server. You can also
choose to enable SSL support by checking that option. The certificate
file path can also be specified. By clicking ,
the default directory /etc/apache2/ssl.crt is displayed.
After all information has been entered, click to continue
to the final step of configuration.
This is the final step of the wizard. Here, determine how and when the Apache server is started: when booting or manually. The port selected earlier is also displayed along with the default and virtual hosts. If you are satisfied with your settings, click to complete configuration.
The HTTP Server module also lets you make even more adjustments to the configuration. Click to see more configuration options. The following changes can then be made:
Selecting the setting and clicking opens a new window in which you can add, delete, or edit entries.
By selecting the settings and clicking , you can change the status of Apache2 modules by clicking . Click to add a new module.
Selecting and clicking lets you edit host settings. You can also add, edit, or delete options.
By selecting and clicking , you can add, delete, edit, or select a host as the default.
In all of the preceding dialogs, you can click to view the error log and access log. Click to complete configuration and return to the YaST Control Center.
To add an SSL option to the host, click from step three (default host) of the HTTP Server Wizard. If your server has already been set up and you no longer have access to the wizard, you can set up an SSL option by selecting from the HTTP Server Configuration dialog or clicking , and . In both cases, a pop-up window appears in which you scroll to an option and confirm with . You are then asked to enter a value for the option selected. This may be as simple as setting the value to on or off, however, the dialog may require that you enter an appropriate value. If uncertain, refer to documentation for value parameters when configuring SSL. After you click , the option and value appear in the host configuration list. Clicking takes you to the next step in the configuration dialog.
If appears in the host configuration list, click to open the SSL configuration dialog. If it is not displayed, click , select, and and the dialog opens automatically. Here, add, delete, or edit SSL options. Click to return to the HTTP Server Wizard.
Configuring Apache manually involves editing the plain text configuration
files as the user root.
| No SuSEconfig Module for Apache2 |
|---|---|
The SuSEconfig module for Apache2 has been removed
from SUSE Linux. It is no longer necessary to run
| |
/etc/sysconfig/apache2 controls some global settings of
Apache, like modules to load, additional configuration files to
include, flags with which the server should be started, and flags that should
be added
to the command line. Every configuration option in
this file is extensively documented and therefore not
mentioned here. For a general-purpose Web server,
/etc/sysconfig/apache2 should be sufficient for any
configuration needs. If a specific configuration is needed, refer
to Section 46.3.2.2, “Apache Directives in /etc/apache2/httpd.conf: Global Environment
”.
| Files Created Automatically on Server Start |
|---|---|
Do not edit these files manually. Instead, edit the corresponding
settings in | |
For fine-grained configuration tweaks, look at the files in
/etc/apache2/*, specifically for changes on manual
configuration of virtual hosts, the global environment, or the main server.
SUSE Linux uses /etc/apache2/httpd.conf as a
central point of reference for other configuration files. Edit the file
only to enable features that are not available in
/etc/sysconfig/apache2.
The directives in the Global
Environment section of httpd.conf
affect the overall operation of Apache.
The following sections describe some of the directives that are not
available in YaST. Core directives like Document Root
(Document Root) are
essential and required both in Global
Environment and for VirtualHost.
The following parameters and directives are ordered by logical affiliation
and configuration scope. All of these should be set in
/etc/apache2/httpd.conf.
The LoadModule directive specifies an Apache module
to load at runtime. module_identifier is
the name of the module according to its documentation.
/path/to/module can be an absolute or
relative path pointing to the file.
Example 46.1. LoadModule Directive
LoadModule rewrite_module /usr/lib/apache2-prefork/mod_rewrite.so
On SUSE Linux, it is not necessary to use LoadModule
statements directly. Instead, APACHE_MODULE is used in
/etc/sysconfig/apache2.
The maximum number of clients Apache can handle concurrently. MaxClients must be large enough to handle as many simultaneous requests as the Web site expects to receive, but small enough to assure that there is enough physical RAM for all processes.
The directives in the Main Server section apply when
client requests are not handled by any VirtualHost and
therefore need to be processed by a default or main server. Additionally,
the parameters defined in this context
are the defaults for all configured virtual hosts.
As a consequence, all of the directives in the Main
Server can also be set in the VirtualHost
context, overwriting the defaults.
Set which files Apache should search to complete a URL lacking a file
specification. The default setting is index.html.
For example, if the client requests the URL
http://www.example.com/foo/ and the directory
foo contains a file called
index.html, Apache delivers this page to the
client.
Declare multiple files by
separating them with spaces.
This directive can only be used inside a
<Directory></Directory>
declaration. See
Directory.
AllowOverride specifies what access and display
options a .htaccess file (or other files
specified by AccessFileName as described in
Section 46.3.2.3.3, “AccessFileName filenames
”)
can override.
Possible values are:
All
All options can be overridden by a .htaccess
file.
None
No option can be overridden by a .htaccess file.
AuthConfig
Directories can be password protected with the help of a
.htaccess file.
FileInfo
Allows the use of directives controlling document types within a
.htaccess file. A typical example for this is to
configure custom error pages with ErrorDocument
(see http://httpd.apache.org/docs-2.0/mod/core.html#errordocument).
Indexes
In the event that no DirectoryIndex document
is found, this parameter allows Apache to control the display of
directory contents.
Limit
Controls access to a directory or to certain files for clients. The
directives Allow, Deny, and
Order are used within a
.htaccess file for this purpose. For usage of
these directives, see the access
module documentation
(http://httpd.apache.org/docs-2.0/mod/mod_access.html).
Options
Allow the usage of the Options and
XBitHack directives within a
.htaccess file. The Options
directive
(http://httpd.apache.org/docs-2.0/mod/core.html#options)
controls which server features are
available in a particular directory. The XBitHack directive
(http://httpd.apache.org/docs-2.0/mod/mod_include.html#xbithack)
allows files with the execute bit set to be parsed as SSI
(see Section 46.5.1.1, “Server-Side Includes with mod_include
”).
| Important |
|---|---|
These settings are applied recursively to the current directory and its
subdirectories.
These options, except | |
AccessFileName sets the name for the files that can
override the global access permissions and other settings for
directories (see
Directory).
The default setting is .htaccess.
Declare multiple files by separating them with spaces.
Specifies the name of the file to which Apache logs error messages.
Alternatively, Apache can also log to a command or script.
The default setting is /var/log/apache2/error_log.
This sets the verbosity of the log messages to record. In
ascending order of level of verbosity (and descending severity of
messages), level can be
emerg
alert
crit
error
warn
notice
info
debug
The default setting is warn, which is recommended for
everyday operation. For debugging purposes, info
and debug provide helpful information.
To maintain multiple domains or hostnames on one physical machine,
VirtualHost containers are needed. They are declared
in Virtual Hosts sections of the configuration.
For more details on the syntax for and functionality of virtual hosts,
refer to Section 46.4, “Virtual Hosts”.
To activate the Apache Web server at boot time, use YaST's runlevel editor. To start it, select + in YaST. Then navigate to the entry. Choose to have Apache start automatically when the machine is booted. Experienced users may want to use the chkconfig tool to achieve the same on the command line: /sbin/chkconfig -a apache2.
To start or stop Apache, use the /usr/sbin/rcapache2
script as the root
user. /usr/sbin/rcapache2 takes the following
parameters for starting and stopping the Apache Web server:
start
Starts the Apache Web Server.
startssl
Starts the Apache Web Server with SSL support. For information about
configuring Apache
with SSL, refer to
Section 46.3.1.3, “Adding SSL Support”
and Section 46.5.2.2, “Secure Sockets Layer and Apache: mod_ssl”.
stop
Stops the Apache Web server.
configtest
Tests the Apache configuration without actually stopping, starting, or restarting the Web server. Because this test is forced everytime the server is started, reloaded, or restarted, it is usually not necessary to run the test explicitly.
restart
First stops then starts the Web server again.
try-restart
Restarts the Web server if it is running.
restart-hup
Restarts the Apache Web server by sending it a
SIGHUP signal. This is normally not used.
graceful and reload
Stops the Web server by advising all forked Apache processes to first finish their request before shutting down. As each process dies, it is replaced by a newly started one, resulting in complete "restart" of Apache.
![[Tip]](admon/tip.png) | Tip |
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rcapache2 | |
status
Checks the runtime status of the Apache Web server.
Example 46.7. Example Output When Starting and Stopping Apache
tux@sun # rcapache2 status
Checking for httpd2: unused
tux@sun # rcapache2 configtest
Syntax OK
tux@sun # rcapache2 start
Starting httpd2 (prefork) done
tux@sun # rcapache2 status
Checking for httpd2: running
tux@sun # rcapache2 graceful
Reload httpd2 (graceful restart) done
tux@sun # rcapache2 status
Checking for httpd2: running
A malformed configuration file can result in Apache not starting correctly or not starting at all. When not starting at all, there might not even be any message displayed. Always check the main error log for every start and restart.
