Add hostname resolution to deploy host

This addresses an issue with delegation to containers noticed
as a result of https://github.com/ansible/ansible/issues/72776
which causes the container host to be accessed by its hostname.

Where a separate deploy host is used, up to now this has not had
its hosts file modified. This patch applies the same /etc/hosts
entries to the deploy host which are used elsewhere.

Change-Id: I82b48ba5cfe6e533426e7098c455b729084b2d51

defaults/main.yml

@@ -34,10 +34,12 @@ openstack_host_sysstat_statistics_hour: 23
 # Options are 'present' and 'latest'
 openstack_hosts_package_state: "latest"
 
-## Enable/disable /etc/hosts file management
+## Enable/disable /etc/hosts file management on OSA managed hosts
 ## You should make other arrangements for name resolution
-## of OSA containers and hosts if disabling this
+## of OSA containers and hosts if disabling these
 openstack_host_manage_hosts_file: true
+## Enable/disable /etc/hosts file management on OSA deploy host
+openstack_host_manage_deploy_hosts_file: true
 
 ## kernel modules for specific group hosts
 openstack_host_specific_kernel_modules: []

releasenotes/notes/deploy-hosts-file-657a385568f3df9c.yaml

@@ -0,0 +1,13 @@
+---
+features:
+  - |
+    In deployments where a separate host is used to manage the OpenStack
+    Ansible configuration, the '/etc/hosts' file on that host will now include
+    a section adding hostname to IP resolution for all hosts in the inventory.
+    This can be enabled/disabled via 'openstack_host_manage_deploy_hosts_file'.
+issues:
+  - |
+    Where a single OSA deploy host is used to manage multiple deployments, some
+    delegated Ansible tasks are performed using hostnames rather than IP
+    addresses due to Ansible issue 72776. Hostnames such as 'infra1' will be
+    ambiguous, so use of separate hosts for each deployment is recommended.

tasks/main.yml

@@ -50,10 +50,10 @@
 # Configure host files should apply to all nodes
 - name: Configure etc hosts files
   import_tasks: openstack_update_hosts_file.yml
-  when:
-    - openstack_host_manage_hosts_file | bool
   tags:
     - openstack_hosts-config
+  when:
+    - (openstack_host_manage_hosts_file | bool) or (openstack_host_manage_deploy_hosts_file | bool)
 
 - name: Remove the blacklisted packages
   package:

tasks/openstack_update_hosts_file.yml

@@ -42,3 +42,16 @@
     dest: /etc/hosts
     block: "{{ _etc_hosts_content | join('\n') }}"
     marker: "### {mark} OPENSTACK-ANSIBLE MANAGED BLOCK ###"
+  when:
+    - openstack_host_manage_hosts_file | bool
+
+- name: Update hosts file on deploy host
+  blockinfile:
+    dest: /etc/hosts
+    block: "{{ _etc_hosts_content | join('\n') }}"
+    marker: "### {mark} OPENSTACK-ANSIBLE {{ lookup('env', 'OSA_CONFIG_DIR') }} MANAGED BLOCK ###"
+  run_once: True
+  delegate_to: localhost
+  become: True
+  when:
+    - openstack_host_manage_deploy_hosts_file | bool