ext_unix_group_acl(8)

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version 7.7 · 7 versions
, in alpine 3.23, alpine 3.24, arch rolling, fedora 43, fedora 44, nixos 26.05, nixpkgs unstable, ubuntu resolute, ubuntu stonking

💖 ext_unix_group_acl — Squid UNIX Group ACL helper 💖

okay so bestie, you know squid? the proxy? yeah. this is one of its little helper besties, ext_unix_group_acl(8) from the System Manager's Manual, and she is so useful, no cap.

✨ NAME ✨

ext_unix_group_acl — the Squid UNIX Group ACL helper 🎀

✨ SYNOPSIS ✨

ext_unix_group_acl [-d] [-g group ] [-g group  ...] [-p] [-s]

✨ DESCRIPTION ✨

So basically, ext_unix_group_acl lets Squid base its access controls on whether a user is a member of a UNIX group. that's it, that's the whole vibe. it's giving "who's allowed in the group chat" energy 💅

✨ OPTIONS ✨

  • -d — writes debug info to stderr. very "tell me everything" of her 🙈
  • -g group — names a group to match. you can stack these up, -g group ... style, one per group, slay
  • -p — also matches the user's primary group from /etc/passwd. yes, the primary one, not just the side quests ✨
  • -s — strips the NT domain name component off user names (the / or \ separated part). bye felicia to the domain prefix 👋

✨ CONFIGURATION ✨

here's a squid.conf moment that defines two Squid acls. usergroup1 matches users in group1, and usergroup2 matches users in group2 or group3:

external_acl_type unix_group %LOGIN
/usr/local/squid/libexec/ext_unix_group_acl -p
acl usergroup1 external unix_group group1
acl usergroup2 external unix_group group2 group3

okay and important: by default up to 11 groups can be matched in one acl (and yes, that count includes the groups you specified on the commandline). this limit is defined by MAX_GROUPS in the source code. so like, know your limits bestie 💀

✨ KNOWN ISSUES ✨

She does not understand GID aliased groups — you know, the ones people sometimes use to work around group size limitations. so if you're out here using GID aliased groups, you have to specify each alias by name. no shortcuts, sorry 🫶

✨ AUTHOR ✨

This program was written by Rodrigo Campos <rodrigo@geekbunker.org> 👑

This manual was written by Henrik Nordstrom <hno@squid-cache.org> ✨

 * Copyright (C) 1996-2026 The Squid Software Foundation and
contributors
 *
 * Squid software is distributed under GPLv2+ license and includes
 * contributions from numerous individuals and organizations.
 * Please see the COPYING and CONTRIBUTORS files for details.

This program and documentation is copyright to the authors named above.

Distributed under the GNU General Public License (GNU GPL) version 2 or later (GPLv2+).

✨ QUESTIONS ✨

Got questions about how to use this program? send them to the Squid Users mailing list <squid-users@lists.squid-cache.org> 💌

✨ REPORTING BUGS ✨

Bug reports need to be made in English. See https://wiki.squid-cache.org/SquidFaq/BugReporting for the deets on what you need to include with your bug report. like, pls include the stuff, it helps 😭

Report bugs or bug fixes using https://bugs.squid-cache.org/

Report serious security bugs to Squid Bugs <squid-bugs@lists.squid-cache.org> 🔥

Report ideas for new improvements to the Squid Developers mailing list <squid-dev@lists.squid-cache.org> 🌈

Additionally bugs or bug-fixes can be reported to Rodrigo Campos <rodrigo@geekbunker.org> 🫶

✨ SEE ALSO ✨

squid(8), group(5), passwd(5), GPL(7), The Squid FAQ wiki https://wiki.squid-cache.org/SquidFaq The Squid Configuration Manual http://www.squid-cache.org/Doc/config/

and that's the whole page bestie!! this one's dated 12 August 2002 and she's the ext_unix_group_acl(8) girlie forever. go forth and ACL responsibly 💖✨🎀🦋

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