How to enable or disable Apache modules

Apache is a widely used web server that supports a modular architecture. This allows administrators to add or remove specific functionalities by enabling or disabling modules. Managing these modules effectively is crucial for optimizing the performance and security of your Apache server. The process varies depending on the Linux distribution in use.

On Debian-based systems like Ubuntu, the a2enmod and a2dismod commands are available for managing modules. These commands simplify the process by automatically adjusting the configuration files. For distributions like RedHat and CentOS, module management requires manually editing the configuration files to add or remove LoadModule directives.

Understanding the differences in these methods ensures that you can effectively manage your Apache server in any environment. Whether through command-line utilities or manual configuration, these techniques allow you to control which modules are active, thereby tailoring the server to your specific needs.

Options	Debian, Ubuntu	openSUSE and SLES	Fedora Core, CentOS, RHEL	macOS	homebrew	xampp
a2enmod support	yes	yes	no	no	no	no
Loadmodule directive	n/a			LoadModule <module_name>_module <module_location>/mod_<module_name>.so

Steps to enable or disable Apache modules using a2enmod and a2dismod:

The a2enmod command is used to enable an Apache module, while a2dismod is used to disable a module. These commands are specific to Debian-based systems such as Ubuntu. They work by creating or removing symbolic links in the Apache configuration directory. This method is quick and straightforward, making it a preferred choice for many administrators.

To manage Apache modules using these commands, first, ensure that the desired module is installed. Then, use a2enmod to enable the module or a2dismod to disable it. Finally, restart the Apache service to apply the changes.

List available modules.

$ ls /etc/apache2/mods-available/
access_compat.load    dir.conf                  proxy_express.load
actions.conf          dir.load                  proxy_fcgi.load
actions.load          dump_io.load              proxy_fdpass.load
alias.conf            echo.load                 proxy_ftp.conf
alias.load            env.load                  proxy_ftp.load
allowmethods.load     expires.load              proxy_hcheck.load
asis.load             ext_filter.load           proxy_html.conf
auth_basic.load       file_cache.load           proxy_html.load
auth_digest.load      filter.load               proxy_http2.load
auth_form.load        headers.load              proxy_http.load
authn_anon.load       heartbeat.load            proxy.load
authn_core.load       heartmonitor.load         proxy_scgi.load
authn_dbd.load        http2.conf                proxy_uwsgi.load
authn_dbm.load        http2.load                proxy_wstunnel.load
##### snipped

List enabled modules.

$ ls /etc/apache2/mods-enabled/
access_compat.load  authz_user.load  filter.load       proxy_http.load
alias.conf          autoindex.conf   mime.conf         proxy.load
alias.load          autoindex.load   mime.load         reqtimeout.conf
auth_basic.load     deflate.conf     mpm_event.conf    reqtimeout.load
authn_core.load     deflate.load     mpm_event.load    setenvif.conf
authn_file.load     dir.conf         negotiation.conf  setenvif.load
authz_core.load     dir.load         negotiation.load  status.conf
authz_host.load     env.load         proxy.conf        status.load

Install module if not already installed.

Related: How to install Apache modules

Enable module using a2enmod utility.

$ sudo a2enmod rewrite
Enabling module rewrite.
To activate the new configuration, you need to run:
  systemctl restart apache2

Disable module using a2enmod utility.

$ sudo a2dismod status
Module status disabled.
To activate the new configuration, you need to run:
  systemctl restart apache2

Reload or restart the Apache service to apply the changes.
```
$ sudo systemctl restart apache2
```
Related: How to manage the Apache web server service

Check if modules are loaded.

$ sudo a2query -m rewrite
[sudo] password for user: 
rewrite (enabled by site administrator)

Steps to enable or disable Apache modules manually:

For systems that do not support a2enmod and a2dismod, module management requires manual editing of the Apache configuration files. This method is universal and works across all Linux distributions. It involves adding or removing LoadModule directives in the appropriate configuration files.

To manually enable or disable a module, open the configuration file where the LoadModule directive is located. Add the directive to enable the module, or comment it out to disable it. After making changes, restart the Apache service to apply them.

Open the terminal.
Install module if not already installed.

Related: How to install Apache modules

Check for existing LoadModule directives.

$ sudo grep -nr LoadModule /etc/{httpd,apache2}
/etc/httpd/conf/httpd.conf:53:# have to place corresponding `LoadModule' lines at this location so the
/etc/httpd/conf/httpd.conf:59:# LoadModule foo_module modules/mod_foo.so
/etc/httpd/conf.modules.d/00-base.conf:6:LoadModule access_compat_module modules/mod_access_compat.so
/etc/httpd/conf.modules.d/00-base.conf:7:LoadModule actions_module modules/mod_actions.so
/etc/httpd/conf.modules.d/00-base.conf:8:LoadModule alias_module modules/mod_alias.so
/etc/httpd/conf.modules.d/00-base.conf:9:LoadModule allowmethods_module modules/mod_allowmethods.so
/etc/httpd/conf.modules.d/00-base.conf:10:LoadModule auth_basic_module modules/mod_auth_basic.so
/etc/httpd/conf.modules.d/00-base.conf:11:LoadModule auth_digest_module modules/mod_auth_digest.so
/etc/httpd/conf.modules.d/00-base.conf:12:LoadModule authn_anon_module modules/mod_authn_anon.so
/etc/httpd/conf.modules.d/00-base.conf:13:LoadModule authn_core_module modules/mod_authn_core.so
/etc/httpd/conf.modules.d/00-base.conf:14:LoadModule authn_dbd_module modules/mod_authn_dbd.so
/etc/httpd/conf.modules.d/00-base.conf:15:LoadModule authn_dbm_module modules/mod_authn_dbm.so

Open the Apache configuration file containing the LoadModule directive of the module that you want to enable or disable using your preferred text editor.
```
$ sudo vi /etc/httpd/conf.modules.d/00-base.conf
```
Comment out the LoadModule directive associated with the module to disable a module.
```
#LoadModule rewrite_module modules/mod_rewrite.so
```
Uncomment a commented LoadModule directive to re-enable a module.
```
LoadModule rewrite_module modules/mod_rewrite.so
```
Manually add a LoadModule directive for module that is installed but without a pre-configured LoadModule directive such as in homebrew.
```
LoadModule php_module /opt/homebrew/opt/php/lib/httpd/modules/libphp.so "Mohd Shakir Zakaria"
```
Related: Location for Apache modules
Save and close the configuration file.
Restart the Apache service to apply the changes.
```
$ sudo systemctl restart apache2
```
Related: How to manage the Apache web server service
Check if module is loaded or unloaded.
```
$ httpd -M | grep rewrite
 rewrite_module (shared)
```
Related: Apache binary name for different distribution
Related: How to view a list of modules in Apache

Author: Mohd Shakir Zakaria
Mohd Shakir Zakaria is an experienced cloud architect with a strong development and open-source advocacy background. He boasts multiple certifications in AWS, Red Hat, VMware, ITIL, and Linux, underscoring his expertise in cloud architecture and system administration.

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