NSS-MYHOSTNAME(8)nss-myhostnameNSS-MYHOSTNAME(8)NAMEnss-myhostname - Provide hostname resolution for the locally configured
DESCRIPTIONnss-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.
hosts: files dns myhostname
protocols: db files
services: db files
ethers: db files
rpc: db files
To test, use glibc's getent tool:
$ getent ahosts `hostname`
::1 STREAM omega
In this case the local hostname is omega.
SEE ALSOsystemd(1), systemd-logind.service(8), logind.conf(5), loginctl(1),
pam.conf(5), pam.d(5), pam(8), pam_loginuid(8)systemd 212NSS-MYHOSTNAME(8)