[Ussuri and older] Set python_cmd where we need it

If you use --start-at-tasks, python_cmd may not be defined when we run
the generate configuration or host container tasks.  We should ensure
this variable is set prior to using it.

This variable was no longer used with the transition of the
container-puppet.py items into ansible itself so it only applies for
Ussuri and older.

Change-Id: I956307d5c69cd4d259fb1ab2731fe0001a196c8e
Closes-Bug: #1907858

common/deploy-steps-tasks-step-1.yaml

@@ -268,21 +268,6 @@
   tags:
     - container_startup_configs
 
-- name: gather facts needed by role
-  setup:
-    gather_subset: "!min,python"
-  when: ansible_python is not defined
-  tags:
-    - container_config_tasks
-
-- name: set python_cmd
-  set_fact:
-    python_cmd: "python{{ ansible_python.version.major }}"
-    cacheable: true
-  when: python_cmd is not defined
-  tags:
-    - container_config_tasks
-
 - name: Set host puppet debugging fact string
   set_fact:
     host_puppet_config_debug: "--debug --verbose"

common/generate-config-tasks.yaml

@@ -1,3 +1,18 @@
+- name: Gather facts needed by role if necessary
+  setup:
+    gather_subset: "!min,python"
+  when: ansible_python is not defined
+  tags:
+    - container_config_tasks
+
+- name: set python_cmd if necessary
+  set_fact:
+    python_cmd: "python{{ ansible_python.version.major }}"
+    cacheable: true
+  when: python_cmd is not defined
+  tags:
+    - container_config_tasks
+
 - name: Block for container-puppet tasks (generate config) during step 1 with paunch
   when:
     - enable_paunch|default(true)

common/host-container-puppet-tasks.yaml

@@ -9,6 +9,21 @@
   tags:
     - container_config_tasks
 
+- name: Gather ansible facts if necessary
+  setup:
+    gather_subset: "!min,python"
+  when: ansible_python is not defined
+  tags:
+    - container_config_tasks
+
+- name: Set python_cmd if necessary
+  set_fact:
+    python_cmd: "python{{ ansible_python.version.major }}"
+    cacheable: true
+  when: python_cmd is not defined
+  tags:
+    - container_config_tasks
+
 - name: Block for container-puppet tasks (bootstrap tasks) for step {{ step }} with paunch
   when:
     - enable_paunch|default(true)