User manual

10 Chapter 1 Web Technologies Overview
Hosting More Than One Website
You can host more than one website simultaneously on your web server. Depending
on how you configure your sites, they may share the same domain name, IP address, or
port. The unique combination of domain name, IP address, and port identifies each
separate site. Your domain names must be registered with a domain name authority
such as InterNIC. Otherwise, the website associated with the domain won’t be visible
on the Internet. (There is a fee for each additional name you register.)
If you configure websites using multiple domain names and one IP address, older
browsers that do not support HTTP 1.1 or later (that don’t include the “Host” request
header), will not be able to access your sites. This is an issue only with software
released prior to 1997 and does not affect modern browsers. If you think your users will
be using very old browser software, you’ll need to configure your sites with one
domain name per IP address.
Understanding WebDAV
If you use WebDAV to provide live authoring on your website, you should create realms
and set access privileges for users. Each site you host can be divided into a number of
realms, each with its own set of users and groups that have either browsing or
authoring privileges.
Defining Realms
When you define a realm, which is typically a folder (or directory), the access privileges
you set for the realm apply to all the contents of that directory. If a new realm is
defined for one of the folders within the existing realm, only the new realm privileges
apply to that folder and its contents. For information about creating realms and setting
access privileges, see “Setting Access for WebDAV-Enabled Sites” on page 31.
Setting WebDAV Privileges
The Apache process running on the server needs to have access to the website’s files
and folders. To provide this access, Mac OS X Server installs a user named “www” and a
group named “www” in the server’s Users & Groups List. The Apache processes that
serve webpages run as the www user and as members of the www group. You need to
give the www group read access to files within websites so that the server can transfer
the files to browsers when users connect to the sites. If you’re using WebDAV, the www
user and www group both need write access to the files and folders in the websites. In
addition, the www user and group need write access to the /var/run/davlocks directory.
Understanding WebDAV Security
WebDAV lets users update files in a website while the site is running. When WebDAV is
enabled, the web server must have write access to the files and folders within the site
users are updating. This has significant security implications when other sites are
running on the server, because individuals responsible for one site may be able to
modify other sites.
LL2350.book Page 10 Friday, August 22, 2003 2:32 PM