Update IPA if update_repos is true (the default)

It's risky to leave older IPA when updating ironic and is likely
to break upgrades. Update it by default and add a knob to disable.

Change-Id: Ieb639576a2562b4f5ae72b70fd9ab8fae928c30f

playbooks/roles/bifrost-ironic-install/defaults/main.yml

@@ -88,6 +88,8 @@ deploy_image: "{{http_boot_folder}}/{{deploy_image_filename}}"
 use_cirros: false
 # Download IPA by default
 download_ipa: true
+update_repos: true
+update_ipa: "{{ update_repos }}"
 cirros_deploy_image_upstream_url: https://download.cirros-cloud.net/0.4.0/cirros-0.4.0-x86_64-disk.img
 # By default bifrost will deploy dnsmasq to utilize as an integrated DHCP
 # server.  If you already have a DHCP server, you will need to disable

playbooks/roles/bifrost-ironic-install/tasks/download_ipa_image.yml

@@ -59,7 +59,7 @@
   retries: 5
   delay: 10
   environment: "{{ venv }}"
-  when: test_ipa_kernel_present.stat.exists == false
+  when: update_ipa | bool or test_ipa_kernel_present.stat.exists == false
 
 - name: "Test if IPA image is present"
   stat: path={{ ipa_ramdisk }}
@@ -102,4 +102,4 @@
   retries: 5
   delay: 10
   environment: "{{ venv }}"
-  when: test_ipa_image_present.stat.exists == false
+  when: update_ipa | bool or test_ipa_image_present.stat.exists == false

releasenotes/notes/update-ipa-76691dbca92246b6.yaml

@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    An ironic-python-agent image is now updated every time the installation
+    playbooks are run. This is done to avoid discrepancy between ironic and
+    the ramdisk on updates. Set ``update_ipa`` to ``false`` to prevent the
+    ramdisk update (not recommended) or ``update_repos`` to ``false`` to
+    disable any updates.