grep -r localhost /etc
/etc/hosts:127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
/etc/hosts:::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
/etc/pki/tls/certs/Makefile:KEY=$(TLSROOT)/private/localhost.key
/etc/pki/tls/certs/Makefile:CSR=$(TLSROOT)/certs/localhost.csr
/etc/pki/tls/certs/Makefile:CRT=$(TLSROOT)/certs/localhost.crt
/etc/pki/tls/certs/make-dummy-cert:	echo localhost.localdomain
/etc/pki/tls/certs/make-dummy-cert:	echo root@localhost.localdomain
/etc/sysconfig/network-scripts/network-functions:        '(none)' | 'localhost' | 'localhost.localdomain')
/etc/sysconfig/network-scripts/network-functions:        # ['(none)', 'localhost' or 'localhost.localdomain' are not valid]
/etc/lvm/archive/lv_00000-480904520.vg:creation_host = "localhost.localdomain"	# Linux localhost.localdomain 3.10.0-862.el7.x86_64 #1 SMP Fri Apr 20 16:44:24 UTC 2018 x86_64
/etc/lvm/backup/lv:creation_host = "localhost.localdomain"	# Linux localhost.localdomain 3.10.0-862.el7.x86_64 #1 SMP Fri Apr 20 16:44:24 UTC 2018 x86_64
/etc/lvm/lvm.conf:	#     System IDs beginning localhost are not permitted.
/etc/security/pam_env.conf:# to "localhost" rather than not being set at all
/etc/security/pam_env.conf:#REMOTEHOST	DEFAULT=localhost OVERRIDE=@{PAM_RHOST}
/etc/security/pam_env.conf:#NNTPSERVER	DEFAULT=localhost
/etc/kdump.conf:#           - List of cluster node(s) except localhost, separated by spaces,
/etc/libvirt/qemu.conf:# setting "localhost" will not work.  By default, the host's configured
/etc/pulse/client.conf:; auto-connect-localhost = no
/etc/postfix/main.cf:#inet_interfaces = $myhostname, localhost
/etc/postfix/main.cf:inet_interfaces = localhost
/etc/postfix/main.cf:# The default is $myhostname + localhost.$mydomain.  On a mail domain
/etc/postfix/main.cf:mydestination = $myhostname, localhost.$mydomain, localhost
/etc/postfix/main.cf:#mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
/etc/postfix/main.cf:#mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain,
/etc/postfix/master.cf:#   lmtp    cmd="lmtpd -a" listen="localhost:lmtp" proto=tcp4
/etc/postfix/master.cf:#  mailbox_transport = lmtp:inet:localhost
/etc/postfix/master.cf:#  virtual_transport = lmtp:inet:localhost
/etc/sudoers:# %users  localhost=/sbin/shutdown -h now
/etc/hostname:localhost.localdomain