Web servers

Web servers serve web pages to users.

Apache

The configurations described here are unique to Ubuntu:

Webservers display the webpage at the server IP addr by default
config files are in /etc/apache2
- main config at /etc/apache2/apache2.conf
uses plugins for …
serves content from document root, /var/html/www by default
always reload so site doesnt go down. only restart when enabling a plugin or there are issues

You can run multiple websites on single server with virtual hosts

each virtual host has its own config file to make it unique
to host multiple sites, create .conf file in /etc/apache2/sites-available dir with unique <VirtualHost> stanza for each host
To run one site, you can just replace the default index.html from /var/www/html

Virtual Host setup steps:

Create website content
Upload files to server in document root?, usually /var/www but can be custom location
Make sure www-data owns all files in Document Root
Create site config file and copy into /etc/apache2/sites-available. For example, mysite.com.conf
Enable site with a2ensite (disable with a2dissite) - Ubuntu-specific?
1. a2ensite creates a symlink to your site config file and stores in /etc/apache2/sites-enabled
2. a2dissite deletes the symlink
Reload Apache to refresh config

apt install apache2             # 1. Install
systemctl status apache2        # 2. Verify its running

# ---  --- #
a2ensite mysite.com.conf        # Enable site and reload (abs path not required)
systemctl reload apache2

a2dissite mysite.com.conf       # Disable site and reload (abs path not required)
systemctl reload apache2

Config files

Important config file info:

/etc/apache2/apache2.conf:
- IncludeOptional is where Apache looks for site .conf files
VirtualHost .conf files are stored in /etc/apache2/sites-available and symlinked in /etc/apache2/sites-enabled
- Each site needs its own document root
- Default log files are fine with one site, but create custom files when serving multiple sites
- Name-based Virtualhosts only get one IP addr, so you have to provide the ServerName in the config file
  - Config file example name: 000-virtual-hosts.conf
  - Server filters incoming requests using ServerName, points reqs to DocumentRoot
  - Add as many sites as you want, just make sure your server has enough resources to handle reqs

Research A names, domain names and how to set up Apache

# --- /etc/apache2/apache2.conf --- #
...
# Include the virtual host configurations:
IncludeOptional sites-enabled/*.conf


# --- 000-default.conf --- #
<VirtualHost *:80>                                      # listen to everything (*) on port 80
	...
	ServerAdmin webmaster@localhost                     # email addr displayed in site error messages
	DocumentRoot /var/www/html                          # serve content from this dir
	...
    # APACHE_LOG_DIR set in /etc/apache2/envvars - /var/log/ by default
	ErrorLog ${APACHE_LOG_DIR}/error.log                # Logs site errors
	CustomLog ${APACHE_LOG_DIR}/access.log combined     # Logs incoming HTTP requests
    ...
</VirtualHost>

# --- Sample VirtualHost .conf multiple interfaces --- #
<VirtualHost 10.20.30.40:80>                                        # IP addr IDs the correct network interface
    ...
	ServerAdmin webmaster@localhost
	DocumentRoot /var/www/mysitename                                # Unique DocumentRoot for each site
    ...
	ErrorLog ${APACHE_LOG_DIR}/mysitename.com-error.log             # Unique log file name    
	CustomLog ${APACHE_LOG_DIR}/mysitename.com-access.log combined  # Unique log file name
    ...
</VirtualHost>

# --- Sample name-based VirtualHost .conf single IP addr (VPS) --- #
<VirtualHost *:80>                                                  # All traffic on port 80
    ...
    ServerName firstsite.com                                        # Links incoming reqs to DocumentRoot
	ServerAdmin webmaster@localhost
	DocumentRoot /var/www/firstsite.com                             # Unique DocumentRoot for each site
    ...
	ErrorLog ${APACHE_LOG_DIR}/firstsite.com-error.log              # Unique log file name    
	CustomLog ${APACHE_LOG_DIR}/firstsite.com-access.log combined   # Unique log file name
    ...
</VirtualHost>

<VirtualHost *:80>                                                  # All traffic on port 80
    ...
    ServerName second.com                                           # Links incoming reqs to DocumentRoot
	ServerAdmin webmaster@localhost
	DocumentRoot /var/www/second.com                                # Unique DocumentRoot for each site
    ...
	ErrorLog ${APACHE_LOG_DIR}/second.com-error.log                 # Unique log file name    
	CustomLog ${APACHE_LOG_DIR}/second.com-access.log combined      # Unique log file name
    ...
</VirtualHost>