Merge "[prometheus-alertmanager] use template/first_found instead of merge_yaml."

ansible/roles/prometheus/tasks/config.yml

@@ -44,16 +44,17 @@
 - name: Copying over prometheus alertmanager config file
   vars:
     service: "{{ prometheus_services['prometheus-alertmanager']}}"
-  merge_yaml:
-    sources:
-      - "{{ node_custom_config }}/prometheus/{{ inventory_hostname }}/prometheus-alertmanager.yml"
-      - "{{ node_custom_config }}/prometheus/prometheus-alertmanager.yml"
-      - "{{ role_path }}/templates/prometheus-alertmanager.yml.j2"
+  template:
+    src: "{{ item }}"
     dest: "{{ node_config_directory }}/prometheus-alertmanager/prometheus-alertmanager.yml"
   register: prometheus_confs
   when:
     - inventory_hostname in groups[service.group]
     - service.enabled | bool
+  with_first_found:
+    - "{{ node_custom_config }}/prometheus/{{ inventory_hostname }}/prometheus-alertmanager.yml"
+    - "{{ node_custom_config }}/prometheus/prometheus-alertmanager.yml"
+    - "{{ role_path }}/templates/prometheus-alertmanager.yml.j2"
   notify:
     - Restart prometheus-alertmanager container