nss-myhostname man page

nss-myhostname, libnss_myhostname.so.2 — Provide hostname resolution for the locally configured system hostname.

Synopsis

libnss_myhostname.so.2

Description

nss-myhostname is a plug-in module for the GNU Name Service Switch (NSS) functionality of the GNU C Library (glibc), primarily providing hostname resolution for the locally configured system hostname as returned by gethostname(2). The precise hostnames resolved by this module are:

Various software relies on an always-resolvable local hostname. When using dynamic hostnames, this is traditionally achieved by patching /etc/hosts at the same time as changing the hostname. This is problematic since it requires a writable /etc file system and is fragile because the file might be edited by the administrator at the same time. With nss-myhostname enabled, changing /etc/hosts is unnecessary, and on many systems, the file becomes entirely optional.

To activate the NSS modules, add "myhostname" to the line starting with "hosts:" in /etc/nsswitch.conf.

It is recommended to place "myhostname" last in the nsswitch.conf' "hosts:" line to make sure that this mapping is only used as fallback, and that any DNS or /etc/hosts based mapping takes precedence.

Example

Here is an example /etc/nsswitch.conf file that enables nss-myhostname 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

To test, use glibc's getent tool:

$ getent ahosts `hostname`
::1       STREAM omega
::1       DGRAM
::1       RAW
127.0.0.2       STREAM
127.0.0.2       DGRAM
127.0.0.2       RAW

In this case, the local hostname is omega.

See Also

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

Referenced By

nss-mymachines(8), nss-resolve(8), nss-systemd(8), systemd.directives(7), systemd.index(7).

libnss_myhostname.so.2(8) is an alias of nss-myhostname(8).

systemd 233 nss-myhostname