Apache, one of the most widely used web servers, offers a modular architecture that allows users to extend its functionality by enabling or disabling specific modules. These modules can range from security enhancements to performance optimizations and additional functionalities. Depending on the Linux distribution, Apache provides different methods to manage these modules.

The two primary methods to manage Apache modules are using the a2enmod and a2dismod commands, and manually editing the configuration files to load or unload modules. The former is a more straightforward approach, typically available on Debian-based systems, while the latter offers more control and is universal across all Apache installations. RedHat-based distributions do not have a2enmod and a2dismod, but provides a configuration file with LoadModule directive for every installed Apache modules.

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 (Apache 2 Enable Module) and a2dismod (Apache 2 Disable Module) commands are utilities provided by Debian and its derivatives, like Ubuntu, to simplify the process of enabling and disabling Apache modules. These commands automatically create symbolic links to the module configuration files, making the process seamless.

  1. 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
  2. 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
  3. Install module if not already installed.
  4. Enable module using a2enmod utility.
    $ sudo a2enmod rewrite
    Enabling module rewrite.
    To activate the new configuration, you need to run:
      systemctl restart apache2
  5. Disable module using a2enmod utility.
    $ sudo a2dismod status
    Module status disabled.
    To activate the new configuration, you need to run:
      systemctl restart apache2
  6. Reload or restart the Apache service to apply the changes.
    $ sudo systemctl restart apache2
  7. 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 have the a2enmod and a2dismod utilities, or for administrators who prefer a hands-on approach, modules can be enabled or disabled by manually editing the Apache configuration files. This method involves adding or removing the LoadModule directive for the desired module.

  1. Open the terminal.
  2. Install module if not already installed.
  3. 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
  4. 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
  5. Comment out the LoadModule directive associated with the module to disable a module.
    #LoadModule rewrite_module modules/mod_rewrite.so
  6. Uncomment a commented LoadModule directive to re-enable a module.
    LoadModule rewrite_module modules/mod_rewrite.so
  7. 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"
  8. Save and close the configuration file.
  9. Restart the Apache service to apply the changes.
    $ sudo systemctl restart apache2
  10. Check if module is loaded or unloaded.
    $ httpd -M | grep rewrite
     rewrite_module (shared)
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