Set the Monasca control plane project ID

This assumes that the Monasca control plane project has been
created at an earlier stage. In future this is likely to be
when Monasca is deployed by Kolla.

ansible/overcloud-grafana-configure.yml

@@ -8,6 +8,30 @@
       group_by:
         key: "monitoring_with_grafana_enabled_{{ kolla_enable_grafana | bool }}"
 
+- name: Set the Monasca control plane project ID
+  hosts: monitoring_with_grafana_enabled_True[0]
+  gather_facts: False
+  tags:
+    - grafana
+  vars:
+    venv: "{{ virtualenv_path }}/shade"
+  roles:
+    - role: stackhpc.os-openstackclient
+      os_openstackclient_venv: "{{ venv }}"
+
+  tasks:
+    - name: Look up Monasca control plane project ID
+      shell: >
+        source {{ venv }}/bin/activate &&
+        openstack project show monasca --format json --column id
+      register: monasca_project_show
+      changed_when: False
+      environment: "{{ openstack_auth_env }}"
+
+    - name: Set Monasca control plane ID
+      set_fact:
+        monasca_control_plane_project_id:  "{{ (monasca_project_show.stdout | from_json).get('id') }}"
+
 - name: Configure control plane monitoring for Grafana
   # Only required to run on a single host.
   hosts: monitoring_with_grafana_enabled_True[0]