systemd-userdbd.service(8) — Linux manual page

SYSTEMD-U....SERVICE(8)  systemd-userdbd.service SYSTEMD-U....SERVICE(8)

NAME

       systemd-userdbd.service, systemd-userdbd - JSON User/Group Record
       Query Multiplexer/NSS Compatibility

SYNOPSIS

       systemd-userdbd.service

       /usr/lib/systemd/systemd-userdbd

DESCRIPTION

       systemd-userdbd is a system service that multiplexes user/group
       lookups to all local services that provide JSON user/group record
       definitions to the system. In addition it synthesizes JSON
       user/group records from classic UNIX/glibc NSS user/group records
       in order to provide full backwards compatibility. It may also
       pick up statically defined JSON user/group records from files in
       /etc/userdb/, /run/userdb/, /run/host/userdb/ and
       /usr/lib/userdb/ with the ".user" extension.

       Most of systemd-userdbd's functionality is accessible through the
       userdbctl(1) command.

       The user and group records this service provides access to follow
       the JSON User Records[1] and JSON Group Record[2] definitions.
       This service implements the User/Group Record Lookup API via
       Varlink[3], and multiplexes access other services implementing
       this API, too. It is thus both server and client of this API.

       This service provides three distinct Varlink[4] services:
       io.systemd.Multiplexer provides a single, unified API for
       querying JSON user and group records. Internally it talks to all
       other user/group record services running on the system in
       parallel and forwards any information discovered. This simplifies
       clients substantially since they need to talk to a single service
       only instead of all of them in parallel.
       io.systemd.NameServiceSwitch provides compatibility with classic
       UNIX/glibc NSS user records, i.e. converts struct passwd and
       struct group records as acquired with APIs such as getpwnam(1) to
       JSON user/group records, thus hiding the differences between the
       services as much as possible.  io.systemd.DropIn makes JSON
       user/group records from the aforementioned drop-in directories
       available.

SEE ALSO

       systemd(1), nss-systemd(8), userdbctl(1),
       systemd-homed.service(8)

NOTES

        1. JSON User Records
           https://systemd.io/USER_RECORD

        2. JSON Group Record
           https://systemd.io/GROUP_RECORD

        3. User/Group Record Lookup API via Varlink
           https://systemd.io/USER_GROUP_API

        4. Varlink
           https://varlink.org/

COLOPHON

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have
       a bug report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2024-06-13.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

systemd 257~devel                                SYSTEMD-U....SERVICE(8)

Pages that refer to this page: userdbctl(1), systemd.directives(7), systemd.index(7), nss-systemd(8)

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