Install coreutils package before using configdrive role

On seed hypervisors running CentOS 8, the configdrive role will fail to
install coreutils if coreutils-single is already present:

Error:
 Problem: problem with installed package coreutils-single-8.30-6.el8.x86_64
  - package coreutils-8.30-6.el8_1.1.x86_64 conflicts with coreutils-single provided by coreutils-single-8.30-6.el8.x86_64
  - package coreutils-8.30-6.el8_1.1.x86_64 conflicts with coreutils-single provided by coreutils-single-8.30-6.el8_1.1.x86_64
  - conflicting requests

Until the role handles it, install coreutils using the --allowerasing
option which will remove coreutils-single at the same time. Use a
command task for now since this option has just been added to
ansible:devel [1].

[1] https://github.com/ansible/ansible/pull/48319

Change-Id: I43bbe9dae3d6796e308fbf66cb04d16b57ff5e37
Story: 2007612
Task: 39607

ansible/seed-vm-provision.yml

@@ -11,6 +11,17 @@
           currently {{ groups['seed'] | length }}.
       when: groups['seed'] | length != 1
 
+    # NOTE(priteau): On seed hypervisors running CentOS 8, the configdrive role
+    # will fail to install coreutils if coreutils-single is already present.
+    # Until the role handles it, install it using the --allowerasing option
+    # which will remove coreutils-single.
+    - name: Ensure coreutils package is installed
+      command: "dnf install coreutils -y --allowerasing"
+      become: True
+      when:
+        - ansible_os_family == 'RedHat'
+        - ansible_distribution_major_version | int >= 8
+
     - name: Ensure the image cache directory exists
       file:
         path: "{{ image_cache_path }}"

releasenotes/notes/fix-coreutils-single-conflict-208036c66b9f7e59.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixes a package conflict while provisioning a seed VM on a CentOS 8 seed
+    hypervisor with ``coreutils-single`` already installed. See `story 2007612
+    <https://storyboard.openstack.org/#!/story/2007612>`__ for details.