Squid has hundreds of configuration directives to control it in various ways. It's not possible to discuss all of them here, we'll try to cover the important ones.
Although we generally start the Squid server as root, it never runs with the privileges of the root user. Right after starting, Squid changes its real UID (User ID)/GID (Group ID) to the user determined by the directive
cache_effective_user. By default, it is set to
nobody. We can create a separate user for running Squid and set the value of this directive accordingly. For example, on some operating systems, Squid is run as
squid user. The corresponding configuration line will be as follows: