20/01/10

To configure, edit httpd.conf
  - Directives and comments
  - After editing, restart server to take effect

Basic set of directives

  - Listen: specifies IP address(es) and/or port number(s)

  - ServerName: in simplest case, specifies the hostname
    Why does the server need to know the server name?
    - clients can include the name in requests
      for name-based virtual hosts
    - server can inlude the name in responses
      for redirects.
    If omitted, server will automatically ask DNS to perform
    reverse DNS lookup: from server's IP address to hostname.
    But there may be problems with this (e.g. if server has
    more than one IP address, or if DNS is down).
    Hence, better to specify it explicitly.

  - User, Group
    E.g.
    User webserv
    Group webserv
    In practice, server is run as root. But this gives it
    full privileges, which is risky (e.g. if a module is
    buggy or malicious).
    So it starts as root, then creates child processes
    to handle requests.
    The child processes run as this User and Group (e.g.
    webserv), which has lower privileges.

  - ServerAdmin
    Email address that can be included in Apache error
    pages.

  - ServerRoot
    If Apache hasn't been installed in default location
    (/usr/local/apache/), this directive says where it 
    has been installed.

  - ErrorLog, TransferLog
    A relative pathname (relative to ServerRoot) where logs
    will be kept. 

  - DocumentRoot
    Common to move the web site out of ServerRoot to some
    other part of the filesystem.
    This directive says where it is.
    When a client request arrives, the pathname in the URL
    is translated into an actual pathname in the filesystem
    by prepending the DocuemtRoot.