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 |