Using loop instead of with_X

The loop keyword is the current recommended way to handle loops,
and supports filters.
It's available since Ansible version 2.5 so changing ansible
requirement in driver-requirements.

Change-Id: Ibff1f07ca00b8f5a5274d73f9e53196f49c33a66

doc/source/admin/drivers/ansible.rst

@@ -125,7 +125,7 @@ Requirements
 ============
 
 Ansible
-    Tested with, and targets, Ansible 2.4.x
+    Tested with, and targets, Ansible 2.5.x
 
 Bootstrap image requirements
 ----------------------------

driver-requirements.txt

@@ -14,7 +14,7 @@ python-xclarityclient>=0.1.6
 sushy>=2.0.0
 
 # Ansible-deploy interface
-ansible>=2.4
+ansible>=2.5
 
 # HUAWEI iBMC hardware type uses the python-ibmcclient library
 python-ibmcclient>=0.1.0

ironic/drivers/modules/ansible/playbooks/roles/discover/tasks/main.yaml

@@ -3,7 +3,7 @@
 
 - set_fact:
     ironic_root_device: /dev/{{ item.key }}
-  with_dict: "{{ ansible_devices }}"
+  loop: "{{ ansible_devices | dict2items | sort(attribute='key') }}"
   when:
     - ironic_root_device is undefined
     - item.value.host

releasenotes/notes/ansible-loops-de0eef0d5b79a9ff.yaml

@@ -0,0 +1,5 @@
+---
+upgrade:
+  - |
+    Changing minimum version of Ansible for use with the ``ansible``
+    ``deploy_interface`` to version 2.5.