prometheus: Add friendly instance labels for ironic and alertmanager

These were omitted from I387c9d8f5c01baf6054381834ecf4e554d0fff35 and
I387c9d8f5c01baf6054381834ecf4e554d0fff35.

Closes-Bug: #2041855
Change-Id: I25e5450d1caeebd9c900c190fc0079988f1ca574

ansible/roles/prometheus/templates/prometheus.yml.j2

@@ -226,6 +226,10 @@ scrape_configs:
     static_configs:
 {% for host in groups['ironic-conductor'] %}
       - targets: ["{{ 'api' | kolla_address(host) | put_address_in_context('url') }}:{{ hostvars[host]['ironic_prometheus_exporter_port'] }}"]
+{% if hostvars[host].prometheus_instance_label | default(false, true) %}
+        labels:
+          instance: "{{ hostvars[host].prometheus_instance_label }}"
+{% endif %}
 {% endfor %}
 {% endif %}
 
@@ -247,5 +251,9 @@ alerting:
     - targets:
 {% for host in groups["prometheus-alertmanager"] %}
         - '{{ 'api' | kolla_address(host) | put_address_in_context('url') }}:{{ hostvars[host]['prometheus_alertmanager_port'] }}'
+{% if hostvars[host].prometheus_instance_label | default(false, true) %}
+        labels:
+          instance: "{{ hostvars[host].prometheus_instance_label }}"
+{% endif %}
 {% endfor %}
 {% endif %}

releasenotes/notes/prom-friendly-label-fix-dc665f81a0aa1081.yaml

+---
+fixes:
+  - |
+    Adds missing support for friendly labels for Prometheus Ironic exporter and
+    Alertmanager metrics. `LP#2041855
+    <https://bugs.launchpad.net/kolla-ansible/+bug/2041855>`__