NSS-MYHOSTNAME(8) nss-myhostname NSS-MYHOSTNAME(8)
NAME
nss-myhostname - Provide hostname resolution for the locally configured system hostname.
SYNOPSIS
nss-myhostname.la
DESCRIPTION
nss-myhostname is a plugin for the GNU Name Service Switch (NSS) functionality of the GNU C Library (glibc) providing hostname resolution
for the locally configured system hostname as returned by gethostname(2). Various software relies on an always-resolvable local hostname.
When using dynamic hostnames, this is usually achieved by patching /etc/hosts at the same time as changing the host name. This however is
not ideal since it requires a writable /etc file system and is fragile because the file might be edited by the administrator at the same
time. nss-myhostname simply returns all locally configured public IP addresses, or, if none are configured, the IPv4 address 127.0.0.2
(which is on the local loopback) and the IPv6 address ::1 (which is the local host) for whatever system hostname is configured locally.
Patching /etc/hosts is thus no longer necessary.
To activate the NSS modules, myhostname has to be added to the line starting with "hosts:" in /etc/nsswitch.conf
It is recommended to put myhostname last in the nsswitch.conf line to make sure that this mapping is only used as fallback, and any DNS or
/etc/hosts based mapping takes precedence.
EXAMPLE
# /etc/nsswitch.conf
passwd: compat
group: compat
shadow: compat
hosts: files 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), systemd-logind.service(8), logind.conf(5), loginctl(1), pam.conf(5), pam.d(5), pam(8), pam_loginuid(8)
systemd 208 NSS-MYHOSTNAME(8)
