SYSTEMD−USERDBD.SERVICE
NAME
SYNOPSIS
DESCRIPTION
SEE ALSO
NOTES
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.
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 Record [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 two 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.NameSeviceSwitch 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.
SEE ALSO
systemd(1), nss-systemd(8), userdbctl(1), systemd-homed.service(8)
NOTES
1. |
JSON User Record |
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/