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.TH "SYSTEMD\-USERDBD\&.SERVICE" "8" "" "systemd 255" "systemd-userdbd.service"
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.SH "NAME"
systemd-userdbd.service, systemd-userdbd \- JSON User/Group Record Query Multiplexer/NSS Compatibility
.SH "SYNOPSIS"
.PP
systemd\-userdbd\&.service
.PP
/usr/lib/systemd/systemd\-userdbd
.SH "DESCRIPTION"
.PP
\fBsystemd\-userdbd\fR
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\&.
.PP
Most of
\fBsystemd\-userdbd\fR\*(Aqs functionality is accessible through the
\fBuserdbctl\fR(1)
command\&.
.PP
The user and group records this service provides access to follow the
\m[blue]\fBJSON User Records\fR\m[]\&\s-2\u[1]\d\s+2
and
\m[blue]\fBJSON Group Record\fR\m[]\&\s-2\u[2]\d\s+2
definitions\&. This service implements the
\m[blue]\fBUser/Group Record Lookup API via Varlink\fR\m[]\&\s-2\u[3]\d\s+2, and multiplexes access other services implementing this API, too\&. It is thus both server and client of this API\&.
.PP
This service provides three distinct
\m[blue]\fBVarlink\fR\m[]\&\s-2\u[4]\d\s+2
services:
\fBio\&.systemd\&.Multiplexer\fR
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\&.
\fBio\&.systemd\&.NameServiceSwitch\fR
provides compatibility with classic UNIX/glibc NSS user records, i\&.e\&. converts
\fBstruct passwd\fR
and
\fBstruct group\fR
records as acquired with APIs such as
\fBgetpwnam\fR(1)
to JSON user/group records, thus hiding the differences between the services as much as possible\&.
\fBio\&.systemd\&.DropIn\fR
makes JSON user/group records from the aforementioned drop\-in directories available\&.
.SH "SEE ALSO"
.PP
\fBsystemd\fR(1),
\fBnss-systemd\fR(8),
\fBuserdbctl\fR(1),
\fBsystemd-homed.service\fR(8)
.SH "NOTES"
.IP " 1." 4
JSON User Records
.RS 4
\%https://systemd.io/USER_RECORD
.RE
.IP " 2." 4
JSON Group Record
.RS 4
\%https://systemd.io/GROUP_RECORD
.RE
.IP " 3." 4
User/Group Record Lookup API via Varlink
.RS 4
\%https://systemd.io/USER_GROUP_API
.RE
.IP " 4." 4
Varlink
.RS 4
\%https://varlink.org/
.RE