enable metrics for memcachedChunks (#260)

* enable metrics for memcachedChunks

* added memcached exporter dashboard

* update command and args of loki memcached

* add comments

* enable service monitor for memcache exporter

terraform/gitops/generate-files/templates/monitoring/install/values-loki.yaml.tpl

@@ -70,6 +70,10 @@ queryFrontend:
     values: ["enabled"]
 
 memcachedchunks:
+  metrics:
+    enabled: true
+    serviceMonitor:
+      enabled: true
   resourcesPreset: medium # https://github.com/bitnami/charts/blob/main/bitnami/common/templates/_resources.tpl
   command:
     - "/opt/bitnami/scripts/memcached/entrypoint.sh"

terraform/gitops/generate-files/templates/monitoring/post-config/dashboards/default.yaml.tpl

@@ -12,4 +12,22 @@ spec:
       dashboards: "grafana"
   grafanaCom:
     id: 249
-    revision: 2
+    revision: 2
+
+---
+
+apiVersion: grafana.integreatly.org/v1beta1
+kind: GrafanaDashboard
+metadata:
+  name: memcached-exporter
+spec:
+  folder: default
+  datasources:
+    - inputName: "DS_PROMETHEUS"
+      datasourceName: "Prometheus" 
+  instanceSelector:
+    matchLabels:
+      dashboards: "grafana"
+  grafanaCom:
+    id: 11527
+    revision: 1