Prevent ceph packages installing from ubuntu-cloud-archive

This patch adds a new variable `openstack_hosts_apt_pinned_packages`
which defaults to pinning ceph packages from the UCA repository to
a lower priority than the equivalent packages from the main ubuntu
repository.

Without this change, installing lxc-templates will pull packages from
the Quincy release of Ceph via Yoga UCA, and this is ahead of the
Pacific version expected by the ceph_client and ceph-ansible code.

This change improves consistency of the ceph packages installed across
the deployment and does not allow very new packages in UCA to later
cause a package downgrade failure when the ceph_client/ceph-ansible
attempts to install the well-defined version of ceph required by
openstack-ansible.

Depends-On: https://review.opendev.org/c/openstack/openstack-ansible/+/838762
Change-Id: Ia19ba6bae3e95ceb2e517039fbbfb9346e014961

defaults/main.yml

@@ -179,3 +179,10 @@ openstack_ca_bundle_path: "{{ _openstack_ca_bundle_path }}"
 
 # extra configuration for OS package manager
 openstack_hosts_package_manager_extra_conf: ''
+
+# apt pins to apply to all hosts in the deployment
+# the default is to make ceph packages from UCA lower priority than those from the ubuntu distro repo
+openstack_hosts_apt_pinned_packages:
+  - package: "src:ceph"
+    origin: "ubuntu-cloud.archive.canonical.com"
+    priority: 400

meta/main.yml

@@ -37,5 +37,7 @@ galaxy_info:
     - openstack
 dependencies:
   - role: apt_package_pinning
+    apt_pinned_packages: "{{ openstack_hosts_apt_pinned_packages }}"
+    apt_package_pinning_file_name: "openstack_hosts_pin.pref"
     when:
       - ansible_facts['pkg_mgr'] == 'apt'

releasenotes/notes/global-apt-pins-a0d6785a8fd662df.yaml

@@ -0,0 +1,20 @@
+---
+features:
+  - |
+    A new variable `openstack_hosts_apt_pinned_packages` is added which allows
+    deployment wide apt pins to be defined in user_variables. The variable defaults
+    to pinning the UCA repository to a priority lower than the Ubuntu repositories for
+    any binary packages generated from the ceph source package. The intention is to
+    ensure that Ceph packages are always installed from the Ubuntu repositories, or
+    alternatively the official ceph repositories if the ceph_client role is run later
+    against a host. The ceph packages for a particular openstack release may not be the
+    same version as those expected by the rest of openstack-ansible so this change ensures
+    consistency in the deployed ceph version.
+upgrade:
+  - |
+    The new variable `openstack_hosts_apt_pinned_packages` is added to the openstack_hosts
+    ansible role and sets the value of `apt_pinned_packages` for the apt_package_pinning
+    role run as a dependancy of the openstack_hosts role. Existing use of the
+    `apt_pinned_packages` variable by deployers in user_variables should be reviewed
+    to ensure that those  pins are applied by the intended ansible roles, and swapped
+    to this new variable if necessary.