nss-systemd - Man Page

Provide UNIX user and group name resolution for user/group lookup via Varlink

Synopsis

libnss_systemd.so.2

Description

nss-systemd is a plug-in module for the GNU Name Service Switch (NSS) functionality of the GNU C Library (glibc), providing UNIX user and group name resolution for services implementing the User/Group Record Lookup API via Varlink[1], such as the system and service manager systemd(1) (for its DynamicUser= feature, see systemd.exec(5) for details) or systemd-homed.service(8).

This module also ensures that the root and nobody users and groups (i.e. the users/groups with the UIDs/GIDs 0 and 65534) remain resolvable at all times, even if they aren't listed in /etc/passwd or /etc/group, or if these files are missing.

This module preferably utilizes systemd-userdbd.service(8) for resolving users and groups, but also works without the service running.

To activate the NSS module, add "systemd" to the lines starting with "passwd:" and "group:" in /etc/nsswitch.conf.

It is recommended to place "systemd" after the "files" or "compat" entry of the /etc/nsswitch.conf lines so that /etc/passwd and /etc/group based mappings take precedence.

Example

Here is an example /etc/nsswitch.conf file that enables nss-systemd correctly:

passwd:         compat mymachines systemd
group:          compat [SUCCESS=merge] mymachines [SUCCESS=merge] systemd
shadow:         compat

hosts:          files mymachines resolve [!UNAVAIL=return] dns myhostname
networks:       files

protocols:      db files
services:       db files
ethers:         db files
rpc:            db files

netgroup:       nis

See Also

systemd(1), systemd.exec(5), nss-resolve(8), nss-myhostname(8), nss-mymachines(8), nsswitch.conf(5), getent(1)

Notes

1.

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

Referenced By

nss-myhostname(8), nss-mymachines(8), nss-resolve(8), systemd.directives(7), systemd.exec(5), systemd.index(7), systemd-userdbd.service(8), userdbctl(1).

The man page libnss_systemd.so.2(8) is an alias of nss-systemd(8).

systemd 245