Allow to add extra records to /etc/hosts

Add variable, that would allow to provide extra records for /etc/hosts
file. That might be useful for ppl who still have not adopted proper
DNS or want to do DNS RR, but not for internal VIP and manage internal
VIP with /etc/hosts file, where each host group would resolve FQDN to
a local address.

Change-Id: I89f8cdebf9322c0451b5600b073c82b7773af164

defaults/main.yml

@@ -38,6 +38,12 @@ openstack_hosts_package_state: "latest"
 openstack_host_manage_hosts_file: true
 ## Enable/disable /etc/hosts file management on OSA deploy host
 openstack_host_manage_deploy_hosts_file: true
+## Provide extra records to /etc/hosts file that would be added
+## to all hosts, if openstack_host_manage_hosts_file is true
+## Example:
+## openstack_host_custom_hosts_records:
+##   - '192.168.1.1 my.fqdn'
+openstack_host_custom_hosts_records: []
 
 ## kernel modules for specific group hosts
 openstack_host_specific_kernel_modules: []

releasenotes/notes/custom_hosts_records-06236cf62a238fc2.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    Added variable ``openstack_host_custom_hosts_records`` that allows
+    deployer to add custom records to /etc/hosts file. It's structure
+    a simple list where each element is a string wich should be placed
+    to /etc/hosts.

tasks/openstack_update_hosts_file.yml

@@ -17,7 +17,7 @@
   run_once: true
   set_fact:
     _etc_hosts_content: |-
-      {% set records = [] %}
+      {% set records = openstack_host_custom_hosts_records %}
       {% for item in groups['all'] %}
       {%   set record = [] %}
       {%   set _target_rfc_name = item|replace('_', '-') %}