[prometheus] Enable ceph mgr exporter

This patch enables the ceph mgr prometheus exporter.

If enable_prometheus_ceph_mgr_exporter is set to true,
the ceph mgr prometheus plugin is enabled on the hosts that are part
of the ceph-mgr group, then the exporter is added into the prometheus-server
configuration file.

Change-Id: Ia2f879401e585e6043f69cc5e3ab1a1f72f7f033

ansible/group_vars/all.yml

@@ -280,6 +280,7 @@ prometheus_node_exporter_port: "9100"
 prometheus_mysqld_exporter_port: "9104"
 prometheus_haproxy_exporter_port: "9101"
 prometheus_memcached_exporter_port: "9150"
+prometheus_ceph_mgr_exporter_port: "9283"
 # Default cadvisor port of 8080 already in use
 prometheus_cadvisor_port: "18080"
 
@@ -849,4 +850,5 @@ enable_prometheus_node_exporter: "{{ enable_prometheus | bool }}"
 enable_prometheus_memcached_exporter: "{{ enable_memcached | bool }}"
 enable_prometheus_cadvisor: "{{ enable_prometheus | bool }}"
 enable_prometheus_alertmanager: "{{ enable_prometheus | bool }}"
+enable_prometheus_ceph_mgr_exporter: "{{ enable_ceph | bool and enable_prometheus | bool }}"
 prometheus_alertmanager_user: "admin"

ansible/roles/ceph/tasks/start_mgrs.yml

@@ -31,3 +31,9 @@
       - "{{ node_config_directory }}/ceph-mgr/:{{ container_config_directory }}/:ro"
       - "/etc/localtime:/etc/localtime:ro"
       - "kolla_logs:/var/log/kolla"
+
+- name: Enable the ceph mgr prometheus module
+  command: docker exec ceph_mgr ceph mgr module enable prometheus
+  when:
+    - inventory_hostname in groups['ceph-mgr']
+    - enable_prometheus_ceph_mgr_exporter | bool

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

@@ -58,6 +58,16 @@ scrape_configs:
 {% endfor %}
 {% endif %}
 
+{% if enable_prometheus_ceph_mgr_exporter | bool %}
+  - job_name: ceph_mgr_exporter
+    honor_labels: true
+    static_configs:
+      - targets:
+{% for host in groups["ceph-mgr"] %}
+        - '{{ hostvars[host]['ansible_' + hostvars[host]['api_interface']]['ipv4']['address'] }}:{{ hostvars[host]['prometheus_ceph_mgr_exporter_port'] }}'
+{% endfor %}
+{% endif %}
+
 {% if enable_prometheus_alertmanager | bool %}
 alerting:
   alertmanagers:

etc/kolla/globals.yml

@@ -500,3 +500,4 @@ tempest_floating_network_name:
 #enable_prometheus_cadvisor: "{{ enable_prometheus | bool }}"
 #enable_prometheus_memcached: "{{ enable_prometheus | bool }}"
 #enable_prometheus_alertmanager: "{{ enable_prometheus | bool }}"
+#enable_prometheus_ceph_mgr_exporter: "{{ enable_prometheus | bool and enable_ceph | bool }}"

releasenotes/notes/prometheus-add-ceph-manager-plugin-7bcde3ec0356e26b.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Exposed a config option to enable the ceph manager prometheus
+    plugin, this also enables the exporter on the prometheus-server
+    configuration for each ceph-mgr host.