мультиплексор запросов на запись пользователя / группы JSON / Совместимость с NSS (JSON User/Group Record Query Multiplexer/NSS Compatibility)
Имя (Name)
systemd-userdbd.service, systemd-userdbd - JSON User/Group Record
Query Multiplexer/NSS Compatibility
Синопсис (Synopsis)
systemd-userdbd.service
/usr/lib/systemd/systemd-userdbd
Описание (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 drop-in
files in /etc/userdb/, /run/userdb/, /run/host/userdb/ and
/usr/lib/userdb/.
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.
Смотри также (See also)
systemd(1), nss-systemd(8), userdbctl(1),
systemd-homed.service(8)
Примечание (Note)
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/