Apache

Overview

• Apache2 server like Nginx, operates in Layer 7/Application Layer. It understands http, https...etc
• It is the first webserver that was deployed over the web.
• Apache2 is extended using modules. Actually module is a shared library.

root@vector:/etc/apache2# a2query 
Usage: /usr/sbin/a2query -q -m [MODULE] -s [SITE] -c [CONF] -a -v -M -d -h 
-q              suppress any output. Useful for invocation from scripts
-m [MODULE]     checks whether the module MODULE is enabled, lists all enabled
                modules if no argument was given
-s [SITE]       checks whether the site SITE is enabled, lists all sites if no
                argument was given
-c [CONF]       checks whether the configuration CONF is enabled, lists all
                configurations if no argument was given
-a              returns the current Apache 2 module magic version
-v              returns the current Apache 2 version
-M              returns the enabled Apache 2 MPM
-d              returns the Apache 2 module directory
-h              display this help
root@vector:/etc/apache2# a2query -d
/usr/lib/apache2/modules/
root@vector:/etc/apache2# 

- Here we can see /usr/lib/apache2/modules/ is the place where modules are installed.