apache.md

apache web server

free and open-source web server

• multiplatform: linux, windows, Unix, FreeBSD, etc

• uses daemon httpd

• apachectl: front end for apache server

  • allows you to:
    • change environment variables

• default directories:

  • Document Root: "/var/www/html"
  • config files:
    • /etc/apache2/ or /etc/httpd/
    • .htaccess

• types of pages

  • root page: page that is displayed when user enters the website
    • DocumentRoot: configuration line that defines the localization of root page
      • DocumentRoot "/var/www/html": apache will look for the root page in this path
  • subpages

example of directory structure if DocumentRoot is set to "/var/www/html":

/var/
  └── www/
      └── html/
          ├── index.html
          ├── about.html
          └── images/
              └── logo.png

• visiting http://yourserver/ will display index.html

• visiting http://yourserver/about.html will display about.html

• visiting http://yourserver/images/logo.png will serve logo.png

• command to start httpd in linux distributions (start can be replaced with restart, stop, etc):

  • red hat: service httpd start;
  • ubuntu: /etc/init.d/apache2 start

• start apache: sudo systemctl start apache2

• stop apache: sudo systemctl stop apache2

• start apache: sudo systemctl restart apache2

parameters

to learn more about parameters, use the terminal command $ man httpd:

• -d serveroot:
• -f config
• -k start|restart|graceful|stop|graceful-stop: signals httpd to start, restart or stop
• configtest:

config files

• httpd.conf or apache2.conf: main config file
  • default path: /etc/httpd/conf or /etc/apache2
• .htaccess: files that define configurations for each directory
• srm.conf: contains settings that define the behaviour of SRM (Storage Resource Management) software
  • default path: /etc/srm
  • defines behaviour for storage systems, for example:
    • paths, capacity and usage policies
• access.conf: contains settings that control document access

example:

# Example Apache configuration snippet
Listen 80                   # Port Apache listens to (default: 80 for HTTP)
ServerName www.example.com  # Domain name

DocumentRoot "/var/www/html"

virtual hosts: allow apache to serve multiple websites/domains from one server

# ubuntu/debian: /etc/apache2/sites-available/example.com.conf
# centos/rhel: /etc/httpd/conf.d/example.com.conf

<VirtualHost *:80>
  ServerName example.com
  ServerAlias www.example.com
  DocumentRoot "/var/www/example"
</VirtualHost>

modules

elements that extend the functionality of Apache HTTP server, allowing it to handle tasks beyond basic web serving

• types of modules:

  • static
    • compiled into apache HTTP server binary build time
    • cannot be loaded or unloaded dynamically without recompiling the server
  • dynamic
    • loaded into apache HTTP server at runtime, without needing to recompile the server
    • can be loaded or unloaded using configuration directives

• core

  • manages server configuration
  • provides HTTP request and responde handling

• mpm_common:

• worker:

• event:

• prefork:

• mpm_netware:

• mpmt_os2:

• mpm_winnt:

sections and directives

log files

testing apache server