Add default-node-count role

This patch adds this new role created from:
- validations/default-node-count.yaml

Change-Id: I5d032004585285764b1e6585da03145b3d312d53
Implements: blueprint validation-framework
Signed-off-by: Gael Chamoulaud <gchamoul@redhat.com>

playbooks/default-node-count.yaml

@@ -0,0 +1,12 @@
+---
+- hosts: undercloud
+  vars:
+    metadata:
+      name: Verify hypervisor statistics
+      description: >
+        This validation checks that the nodes and hypervisor statistics
+        add up.
+      groups:
+      - pre-deployment
+  roles:
+    - default-node-count

roles/default-node-count/meta/main.yml

@@ -0,0 +1,27 @@
+galaxy_info:
+  author: TripleO Validations Team
+  company: Red Hat
+  license: Apache
+  min_ansible_version: 2.4
+
+  platforms:
+  - name: CentOS
+    versions:
+    - 7
+  - name: RHEL
+    versions:
+    - 7
+
+  categories:
+    - cloud
+    - baremetal
+    - system
+  galaxy_tags: []
+    # List tags for your role here, one per line. A tag is a keyword that describes
+    # and categorizes the role. Users find roles by searching for tags. Be sure to
+    # remove the '[]' above, if you add tags to this list.
+    #
+    # NOTE: A tag is limited to a single word comprised of alphanumeric characters.
+    #       Maximum 20 tags per role.
+
+dependencies: []

roles/default-node-count/tasks/main.yml

@@ -0,0 +1,39 @@
+---
+- name: Retrieve the hypervisor statistics
+  set_fact:
+    statistics: "{{ lookup('nova_hypervisor_statistics', wantlist=True) }}"
+
+- name: Get default role counts
+  set_fact:
+    roles_info: "{{ lookup('roles_info', wantlist=True) }}"
+
+- name: Set requested count
+  set_fact:
+    requested_count: "{{ roles_info|sum(attribute='count') }}"
+
+- name: Get associated nodes
+  set_fact:
+    associated_nodes: "{{ lookup('ironic_nodes', 'associated', wantlist=True) }}"
+
+- name: Get available nodes
+  set_fact:
+    available_nodes: "{{ lookup('ironic_nodes', 'provision_state', ['available'], wantlist=True) }}"
+
+- name: Set count of available nodes
+  set_fact:
+    available_count: "{{ ((associated_nodes|length) + (available_nodes|length))|int }}"
+
+- name: Fail when requested is more than available
+  fail:
+    msg: >
+      Not enough baremetal nodes - available: {{ available_count }},
+      requested: {{ requested_count }}
+  failed_when: requested_count|int > available_count|int
+
+- name: Fail when hypervisor count is less than available count
+  fail:
+    msg: >
+      Only {{ statistics.count }} nodes are exposed to Nova of
+      {{ available_count }} requests. Check that enough nodes are
+      in 'available' state with maintenance mode off.
+  failed_when: statistics.count < available_count|int

roles/default-node-count/vars/main.yml

@@ -0,0 +1,8 @@
+---
+metadata:
+  name: Verify hypervisor statistics
+  description: >
+    This validation checks that the nodes and hypervisor statistics
+    add up.
+  groups:
+  - pre-deployment