Provided by: libnss-systemd_245.4-4ubuntu3_amd64
nss-systemd, libnss_systemd.so.2 - Provide UNIX user and group name resolution for user/group lookup via Varlink
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, 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.
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
systemd(1), systemd.exec(5), nss-resolve(8), nss-myhostname(8), nss-mymachines(8), nsswitch.conf(5), getent(1)
1. User/Group Record Lookup API via Varlink https://systemd.io/USER_GROUP_API