How to enable or disable Apache modules

Apache is a modular system in a sense that its functionality could be extended by using modules. A module could be installed into the system and Apache would then be configured to load the module during its startup.

Some of the mostly used modules are PHP and SSL which is to enable support for hosting PHP applications and provide encrypted web traffic respectively.

Apache modules could be enabled and disabled where and when required.

Steps to enable or disable Apache modules:

1. Install required Apache module if not not already installed.

   How to install Apache modules

2. Check if desired module is already loaded or enabled (optional).

   $ apachectl -t -D DUMP_MODULES
   Loaded Modules:
    core_module (static)
    so_module (static)
    watchdog_module (static)
    http_module (static)
    log_config_module (static)
    logio_module (static)
    version_module (static)
    unixd_module (static)
    access_compat_module (shared)
    alias_module (shared)
    auth_basic_module (shared)
    authn_core_module (shared)
    authn_file_module (shared)
    authz_core_module (shared)
    authz_host_module (shared)
    authz_user_module (shared)
    autoindex_module (shared)
    deflate_module (shared)
    dir_module (shared)
    env_module (shared)
    filter_module (shared)
    mime_module (shared)
    mpm_event_module (shared)
    negotiation_module (shared)
    reqtimeout_module (shared)
    setenvif_module (shared)
    socache_shmcb_module (shared)
    status_module (shared)

   Apache binary name for different distribution

   You can also use the -M option instead which is just a shortcut to the above command.

   $ apachectl -M

3. Add desired modules into Apache configuration file using the LoadModule directive.

   LoadModule ssl_module /usr/lib/apache2/modules/mod_ssl.so

   Location for Apache LoadModule configuration

   • Ubuntu and other Debian derivatives along with openSUSE and SLES has a2enmod utility installed and could be used to easily load Apache modules without having to manually configure the LoadModule directive.

     $ sudo a2enmod ssl
     [sudo] password for user:
     Considering dependency setenvif for ssl:
     Module setenvif already enabled
     Considering dependency mime for ssl:
     Module mime already enabled
     Considering dependency socache_shmcb for ssl:
     Module socache_shmcb already enabled
     Enabling module ssl.
     See /usr/share/doc/apache2/README.Debian.gz on how to configure SSL and create self-signed certificates.
     To activate the new configuration, you need to run:
       systemctl restart apache2

   • CentOS, Fedora and Red Hat distributions will automatically load the module so no further action is required.

   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

4. Restart Apache service for the modules to be loaded.

   How to start, restart and stop Apache service

5. Check if module is now enabled.

   $ apachectl -M
   Loaded Modules:
    core_module (static)
    so_module (static)
    watchdog_module (static)
    http_module (static)
    log_config_module (static)
    logio_module (static)
    version_module (static)
    unixd_module (static)
    access_compat_module (shared)
    alias_module (shared)
    auth_basic_module (shared)
    authn_core_module (shared)
    authn_file_module (shared)
    authz_core_module (shared)
    authz_host_module (shared)
    authz_user_module (shared)
    autoindex_module (shared)
    deflate_module (shared)
    dir_module (shared)
    env_module (shared)
    filter_module (shared)
    mime_module (shared)
    mpm_event_module (shared)
    negotiation_module (shared)
    reqtimeout_module (shared)
    setenvif_module (shared)
    socache_shmcb_module (shared)
    ssl_module (shared)
    status_module (shared)

6. Remove the added LoadModule directive or comment out the line by adding # at the beginning to disable loading the module.

   #LoadModule ssl_module /usr/lib/apache2/modules/mod_ssl.so

   Users of Ubuntu and other Debian derivatives along with openSUSE and SLES can use a2dismod utility to disable Apache modules.

   $ sudo a2dismod ssl
   [sudo] password for user:
   Module ssl disabled.
   To activate the new configuration, you need to run:
     systemctl restart apache2

7. Restart Apache service for the modules to be unloaded.