Reduce the default fact gather subset

This patch implements a new default subset of facts being gathered
to a much smaller set. This should improve performance in large
environments. Deployers who need a greater subset are able to use
the standard Ansible environment variables to override our default
value.

Change-Id: I741228ba03ad5081fbea5833143fdf1f1e8d3623

releasenotes/notes/ansible-fact-subset-08e582fcf7ba4e4e.yaml

@@ -0,0 +1,13 @@
+---
+features:
+  - In order to reduce the time taken for fact gathering, the default
+    subset gathered has been reduced to a smaller set than the Ansible
+    default. This may be changed by the deployer by setting the
+    ``ANSIBLE_GATHER_SUBSET`` variable in the bash environment prior
+    to executing any ansible commands.
+upgrade:
+  - In order to reduce the time taken for fact gathering, the default
+    subset gathered has been reduced to a smaller set than the Ansible
+    default. This may be changed by the deployer by setting the
+    ``ANSIBLE_GATHER_SUBSET`` variable in the bash environment prior
+    to executing any ansible commands.

scripts/openstack-ansible.rc

@@ -26,6 +26,8 @@ export ANSIBLE_ACTION_PLUGINS="${ANSIBLE_ACTION_PLUGINS:-/etc/ansible/roles/plug
 export ANSIBLE_CALLBACK_PLUGINS="${ANSIBLE_CALLBACK_PLUGINS:-/etc/ansible/roles/plugins/callback}"
 
 export ANSIBLE_GATHERING="${ANSIBLE_GATHERING:-smart}"
+export ANSIBLE_GATHER_SUBSET="${ANSIBLE_GATHER_SUBSET:-network,hardware,virtual}"
+
 export ANSIBLE_CACHE_PLUGIN="${ANSIBLE_CACHE_PLUGIN:-jsonfile}"
 export ANSIBLE_CACHE_PLUGIN_CONNECTION="${ANSIBLE_CACHE_PLUGIN_CONNECTION:-/etc/openstack_deploy/ansible_facts}"
 export ANSIBLE_CACHE_PLUGIN_TIMEOUT="${ANSIBLE_CACHE_PLUGIN_TIMEOUT:-86400}"

scripts/run-playbooks.sh

@@ -49,14 +49,14 @@ function playbook_run {
   # First we gather facts about the hosts to populate the fact cache.
   # We can't gather the facts for all hosts yet because the containers
   # aren't built yet.
-  ansible -m setup -a "gather_subset=!facter,!ohai" hosts
+  ansible -m setup -a "gather_subset=network,hardware,virtual" hosts
 
   for root_include in $(awk -F'include:' '{print $2}' setup-everything.yml); do
     # Once setup-hosts is complete, we should gather facts for everything
     # (now including containers) so that the fact cache is complete for the
     # remainder of the run.
     if [[ "${root_include}" == "setup-infrastructure.yml" ]]; then
-      ansible -m setup -a "gather_subset=!facter,!ohai" all
+      ansible -m setup -a "gather_subset=network,hardware,virtual" all
     fi
     for include in $(awk -F'include:' '{print $2}' "${root_include}"); do
       echo "[Executing \"${include}\" playbook]"