Administrative Options

Administrative Options provides access to several of the behind-the-scenes options of Squid. This page allows you to configure a diverse set of options, including the user ID and group ID of the Squid process, cache hierarchy announce settings, and the authentication realm (Figure 12-17).

Figure 12-17: Administrative Options

Run as Unix user and group

The username and group name Squid will operate as. Squid is designed to start as root but very soon after drop to the user/group specified here. This allows you to restrict, for security reasons, the permissions that Squid will have when operating. Although Squid has proven itself to be quite secure through several years of use on thousands of sites, it is never a bad thing to take extra precautions to avoid problems. By default, Squid will operate as either nobody user and the nogroup group, or in the case of some Squids installed from RPM, as squid user and group. These options correlate to the cache_effective_user and cache_effective_group directives.

Proxy authentication realm

The realm that will be reported to clients when performing authentication. This option usually defaults to Squid proxy-caching web server, and correlates to the proxy_auth_realm directive. This name will likely appear in the browser popup window when the client is asked for authentication information.

Cache manager email address

The email address of the administrator of this cache. This option corresponds to the cache_mgr directive and defaults to either webmaster or root on RPM-based systems. This address will be added to any error pages that are displayed to clients.

Visible hostname

The host name that Squid will advertise itself on. This effects the host name that Squid uses when serving error messages. This option may need to be configured in cache clusters if you receive IP-forwarding errors. This option configures the visible_hostname.

Unique hostname

Configures the unique_hostname directive, and sets a unique host name for Squid to report in cache clusters in order to allow detection of forwarding loops. Use this if you have multiple machines in a cluster with the same visible hostname.

Cache announce host, port, and file

The host address and port that Squid will use to announce its availability to participate in a cache hierarchy. The cache announce file is simply a file containing a message to be sent with announcements. These options correspond to the announce_host, announce_port, and announce_file directives.

Announcement period

Configures the announce_period directive, and refers to the frequency at which Squid will send announcement messages to the announce host.