Override bridge hostvars directly

Now that we're not using playbook adjacent hostvars, just set
overrides in the test hostvars.

Change-Id: I4598c61dbe28eb965fce9a4578ddf44d785c5ff1

playbooks/zuul/run-base.yaml

@@ -81,29 +81,6 @@
         - host_vars/backup-test02.opendev.org.yaml
     - name: Display group membership
       command: ansible localhost -m debug -a 'var=groups'
-
-    # In prod, bridge installs a zuul user, but in zuul we already have a zuul user, so we really need 
-    # to not modify it.
-    # TODO(mordred) We should be able to replace this with overriding directly.
-    - name: Load bridge hostvars
-      slurp:
-        path: /home/zuul/src/opendev.org/opendev/system-config/inventory/service/host_vars/bridge.openstack.org.yaml
-      register: bridge_hostvar_content
-    - name: Parse bridge_hostvars
-      set_fact:
-        bridge_hostvars: "{{ bridge_hostvar_content.content | b64decode | from_yaml }}"
-    - name: Overwrite extra_users
-      vars:
-        new_config:
-          extra_users: []
-      set_fact:
-        bridge_hostvars: "{{ bridge_hostvars | combine(new_config) }}"
-    - name: Save bridge hostvars
-      copy:
-        content: "{{ bridge_hostvars | to_nice_yaml }}"
-        dest: /home/zuul/src/opendev.org/opendev/system-config/inventory/service/host_vars/bridge.openstack.org.yaml
-      become: true
-
     - name: Run base.yaml
       command: ansible-playbook -f 50 -v /home/zuul/src/opendev.org/opendev/system-config/playbooks/base.yaml
     - name: Run bridge service playbook
@@ -122,9 +99,11 @@
           zuul_job: '{{ zuul.job }}'
           zuul: '{{ zuul }}'
 
+    # The default of '' here is to satisfy ansible-lint, which
+    # otherwise throws a j2 formatting exception.
     - name: Write out testinfra extra data fixture
       copy:
-        content: '{{ testinfra_extra_data | to_nice_yaml }}'
+        content: "{{ testinfra_extra_data | default('') | to_nice_yaml }}"
         dest: '/home/zuul/testinfra_extra_data_fixture.yaml'
 
     - name: Run testinfra to validate configuration

playbooks/zuul/templates/host_vars/bridge.openstack.org.yaml.j2

@@ -66,3 +66,4 @@ gitea_kube_key: Z2l0ZWFfazhzX2tleQ==
 
 ansible_cron_disable_job: true
 cloud_launcher_disable_job: true
+extra_users: []