Use fact for the hostname of the first ceph mon service (#495)

Related to 807f10c

Signed-off-by: Christian Berendt <[email protected]>

playbooks/ceph/validate-ceph-osds.yml

@@ -343,9 +343,14 @@
         _osds_test_up_in_result: "no-result"
         _osds_test_up_in_data: ""
 
+    - name: Set _mon_hostname fact
+      ansible.builtin.set_fact:
+        _mon_hostname: "{{ hostvars[groups[mon_group_name | default('ceph-mon')][0]]['ansible_hostname'] }}"
+      run_once: true
+
     - name: Get ceph osd tree
       community.docker.docker_container_exec:
-        container: "ceph-mon-{{ ansible_hostname }}"
+        container: "ceph-mon-{{ _mon_hostname }}"
         command: "ceph osd tree --format=json"
       register: _osds_tree_raw
       run_once: true