|author||Michał Górny <firstname.lastname@example.org>||2019-05-29 12:16:17 +0200|
|committer||Michał Górny <email@example.com>||2019-06-18 14:23:48 +0200|
|parent||glep-0073: Deferred due to inactivity. (diff)|
glep-0081: User and group management via dedicated packages
Bug: https://bugs.gentoo.org/687420 Signed-off-by: Michał Górny <firstname.lastname@example.org>
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+Title: User and group management via dedicated packages
+Author: Michał Górny <email@example.com>,
+ Michael Orlitzky <firstname.lastname@example.org>
+Type: Standards Track
+A new approach for user/group management is proposed. Regular packages
+in dedicated categories are used to represent and create user and group
+accounts. Dependencies are used to request users and group from within
+regular packages, and to track their usage.
+User management in Gentoo is currently ad-hoc. Users and groups are
+created through calling system tools directly in packages needing them.
+There is no systematic way of tracking which packages need specific
+users or groups, and determining which ones are obsolete. Coordinating
+properties of users and groups used by multiple packages must be done
+manually by developers.
+GLEP 27 originally attempted to address the problem. Posted in 2004,
+it never had reached the reference implementation state, and became
+A good system user and group management proposal should address:
+1. Tracking usage of users and groups, and determining which ones
+ are obsolete.
+2. Sharing users and groups reliably between different packages.
+3. Maintaining fixed UIDs/GIDs that are consistent between different
+4. Providing local overrides for user/group properties.
+5. Ensuring that users and groups are not created unnecessarily
+ at build time.
+6. Providing support for centralized account management (e.g. LDAP).
+At the same time, the proposal should avoid unnecessary complexity
+to avoid sharing the fate of GLEP 27. This proposal aims to address
+those points without requiring a new EAPI or any changes in the package
+Following the acceptance of this GLEP, all new users and groups must
+be created via user/group packages as defined in this GLEP. The old
+method may still be used for existing users/groups, in existing
+All new users and groups must have unique UIDs/GIDs assigned
+by developers. The developer adding them is responsible for checking
+Before adding a new user and/or group, the developer must send a RFC
+to the ``gentoo-dev`` mailing list.
+In this proposal, system users and groups are represented by regular
+packages. Those packages logically represent the ownership of
+the respective users and group, and technically implement their
+User packages are placed in ``acct-user`` category. Each user package
+defines the properties of the particular user, and must be named after
+the user it creates. It must depend at build and run time on the groups
+the user belongs to.
+Group packages are placed in ``acct-group`` category. Each group
+package defines the properties of the particular group, and must be
+named after the group it creates.
+All user and group packages must define preferred fixed UIDs/GIDs,
+and they must be unique within the repository. The packages should
+indicate whether the value needs to be strictly enforced, or whether
+another UID/GID is acceptable when the user exists already or requested
+UID/GID is taken.
+Packages needing a specific user or group use dependencies to pull
+the required user/group packages. If the user is needed at build time,
+a build time dependency (``DEPEND``) must be used. If the user is
+needed at install and/or run time, a run time dependency (``RDEPEND``)
+must be used.
+The primary technical function of user and group packages is to create
+the users and groups. This is done via invoking the respective system
+tools at ``pkg_preinst`` phase. This is done only if the user/group
+does not exist on the system already.
+If the user or group exists already, the package performs necessary
+modifications in order to meet requested properties. This includes
+updating user's home directory path (but not moving the directory
+itself), shell and/or group membership. However, UID/GID is not
+The package must not remove users/groups. When the account is no longer
+needed, the tooling must ensure that it is locked from access.
+Appropriately, the packages must be able to reenable users when they
+are installed again.
+Additional tools may be provided to help users remove groups and users.
+However, such actions need to be explicitly confirmed by the system
+Home directory ownership
+If the user in question uses a regular home directory (i.e. not
+``/dev/null``), the user package should maintain the directory
+via ``keepdir`` command. This allows for clean removal of the home
+directory if it is no longer needed. The package manager will also
+apply correct permissions if the directory does not exist yet.
+Note that since the user is not created until ``pkg_preinst``,
+the permissions to home directory should not be applied earlier than
+Requiring mailing list RFC
+The policy explicitly requires RFCs for new users and groups, as they
+have global scopes and effects of mistakes while adding them are hard
+to fix. Wider review should decrease the risk of major design mistakes.
+To provide one example, right now we have two different packages
+creating ``git`` user and requiring a different home directory for
+the user. As a result, the first package being installed defines
+the actual home directory, and both technically can not be installed
+at the same time.
+Tracking of user/group usage is done through dependencies. As long
+as any installed package depends on a specific user/group package,
+the respective user/group is assumed to be used. If no package
+requiring the specific user/group is left, the package manager
+automatically prunes the package clearly indicating it is no longer
+Each user and group has a single respective package creating it.
+If multiple packages need it, they depend on the same package. This
+ensures that all properties are kept in a single location, and do not
+need to be synced.
+Having a single location with all predefined user/group ranges makes it
+possible to maintain fixed UID/GID definitions. This GLEP makes
+allocating them obligatory. While this isn't enforced for existing
+users, it provides a way forward for new installations.
+Local overrides can be trivially implemented via local repository,
+through overriding the respective user/group ebuilds. The proposal also
+respects direct sysadmin modifications.
+Avoiding unnecessary user/group creation at build time is implemented
+via correct dependency types. While this was possible with the status
+quo, the dependency model should be more natural to developers and cause
+The original proposal attempted to remove user/groups automatically
+when the respective package was unmerged. This required verifying that
+no files are owned by the user/group in question which was both
+expensive in terms of I/O, and fragile.
+This GLEP follows the best practice of leaving obsolete user/groups
+accounts while ensuring that they are locked out properly. This
+guarantees that no files with stale ownership are left
+e.g. on unmounted filesystems) and that the same UID/GID is not reused
+for another user/group.
+This GLEP preserves backwards compatibility with the existing method
+of user/group management. Both methods can coexist as long as necessary
+for the transition period, and the same user/group can be governed
+by both in parallel.
+However, some of the advantages will only be reliable once the old
+method is phased out, and only on new installations. This particularly
+applies to fixed UIDs/GIDs.
+The reference implementation has been submitted to review on gentoo-dev
+mailing list. The version at the time of writing is v4. [#REFIMPL]_
+.. [#GLEP27] GLEP 27: Portage Management of UIDs/GIDs
+.. [#REFIMPL] [gentoo-dev] [PATCH v4 0/9] User/group packages
+This work is licensed under the Creative Commons Attribution-ShareAlike 3.0
+Unported License. To view a copy of this license, visit