Overview¶

As you may have learned from the Asterisk Architecture section, the majority of Asterisk's features and functionality are separated outside of the core into various modules. Each module has distinct functionality, but sometimes relies on another module or modules.

Asterisk provides capability to automatically and manually load modules. Module load order can be configured before load-time, or modules may be loaded and unloaded during run-time.

Configuration¶

The configuration file for Asterisk's module loader is modules.conf. It is read from the typical Asterisk configuration directory. You can also view the sample of modules.conf file in your source directory at configs/modules.conf.sample or on GitHub at this link.

The configuration consist of one large section called "modules" with possible directives configured within.

There are several directives that can be used.

• autoload - When enabled, Asterisk will automatically load any modules found in the Asterisk modules directory.
• preload - Used to specify individual modules to load before the Asterisk core has been initialized. Often used for realtime modules so that config files can be pushed to a backend before the dependent modules are loaded.
• require - Set a required module. If a required module does not load, then Asterisk exits with status code 2.
• preload-require - A combination of preload and require.
• noload - Do not load the specified module.
• load - Load the specified module. Typically used when autoload is set to 'no'.

Let's show a few arbitrary examples below.

[modules]
;autoload = yes
;preload = res_odbc.so
;preload = res_config_odbc.so
;preload-require = res_odbc.so
;require = res_pjsip.so
;noload = pbx_gtkconsole.so
;load = res_musiconhold.so

CLI Commands¶

Asterisk provides a few commands for managing modules at run-time. Be sure to check the current usage using the CLI help with "core show help ".

• module show

Usage: module show [like keyword]
 Shows Asterisk modules currently in use, and usage statistics.

Usage: module load <module name>
 Loads the specified module into Asterisk.

Usage: module unload [-f|-h] <module_1> [<module_2> ... ]
 Unloads the specified module from Asterisk. The -f
 option causes the module to be unloaded even if it is
 in use (may cause a crash) and the -h module causes the
 module to be unloaded even if the module says it cannot, 
 which almost always will cause a crash.

Usage: module reload [module ...]
 Reloads configuration files for all listed modules which support
 reloading, or for all supported modules if none are listed.