This file /etc/cloud/templates/hosts.suse.tmpl is only utilized
if enabled in cloud-config. Specifically, in order to enable it
you need to add the following to config:
# Your system has configured 'manage_etc_hosts' as True.
# As a result, if you wish for changes to this file to persist
# then you will need to either
# a.) make changes to the master file in /etc/cloud/templates/hosts.suse.tmpl
# b.) change or remove the value of 'manage_etc_hosts' in
# /etc/cloud/cloud.cfg or cloud-config from user-data
# The following lines are desirable for IPv4 capable hosts
# The following lines are desirable for IPv6 capable hosts
::1 localhost ipv6-localhost ipv6-loopback