Execute deploy_steps_tasks per step

Instead of including the entire deploy_steps_tasks.yaml tasks file for
each role at each step, use the per-step files and only if they exist.

This cuts down on the amount of time that ansible has to spend skipping
tasks that don't get run at a certain step, which can be significant at
scale.

Change-Id: I06ee04b9b47226433f25e3cff08c461462a907d9
Depends-On: Id5fdb4dd1a6290d1097d2d81523161c87ab6d4dd

common/deploy-steps-tasks-step-0.j2.yaml

@@ -1,4 +1,6 @@
 - name: Deploy step tasks for step 0
+  delegate_to: localhost
+  run_once: true
   debug:
     msg: Use --start-at-task 'Deploy step tasks for step 0' to resume from this task
   when: "tripleo_minor_update is not defined or tripleo_minor_update != 'true'"
@@ -13,6 +15,15 @@
   copy: src=container_puppet_script.yaml dest=/var/lib/container-puppet/container-puppet.sh force=yes mode=0755 setype=container_file_t
 
 {%- for role in roles %}
-- include_tasks: {{role.name}}/deploy_steps_tasks.yaml
-  when: tripleo_role_name == '{{role.name}}'
+- name: Check for {{role.name}}/deploy_steps_tasks_step0.yaml
+  delegate_to: localhost
+  run_once: true
+  become: false
+  stat:
+    path: "{{ '{{' }} playbook_dir ~ '/' ~ '{{role.name}}' ~ '/' ~ 'deploy_steps_tasks_step0.yaml' {{ '}}' }}"
+  register: tasks_stat
+- include_tasks: {{role.name}}/deploy_steps_tasks_step0.yaml
+  when:
+    - tripleo_role_name == '{{role.name}}'
+    - tasks_stat.stat.exists
 {%- endfor %}

common/deploy-steps.j2

@@ -782,8 +782,17 @@ outputs:
                   debug:
                     msg: Use --start-at-task 'Deploy step tasks for {{step}}' to resume from this task
 {%- for role in roles %}
-                - include_tasks: {{role.name}}/deploy_steps_tasks.yaml
-                  when: tripleo_role_name == '{{role.name}}'
+                - name: Check for {{role.name}}/deploy_steps_tasks_step{{step}}.yaml
+                  delegate_to: localhost
+                  become: false
+                  run_once: true
+                  stat:
+                    path: "{{ '{{' }} playbook_dir ~ '/' ~ '{{role.name}}' ~ '/' ~ 'deploy_steps_tasks_step{{step}}.yaml' {{ '}}' }}"
+                  register: tasks_stat
+                - include_tasks: {{role.name}}/deploy_steps_tasks_step{{step}}.yaml
+                  when:
+                    - tripleo_role_name == '{{role.name}}'
+                    - tasks_stat.stat.exists
 {%- endfor %}
               tags:
                 - overcloud