nss-systemd

Index · Directives systemd 234

## Name

nss-systemd, libnss_systemd.so.2 — Provide UNIX user and group name resolution for dynamic users and groups.

## 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 dynamic users and groups allocated through the `DynamicUser=` option in systemd unit files. See systemd.exec(5) for details on this option.

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.

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 mymachines 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)