Postgresql_exporter: Adding queries.yaml file

This change must enable postgresql-exporter to push additional metrics
(like replication_lag) which are derived using a SQL query against Postgres DB.

(Co-Author: Steven Fitzpatrick)

Change-Id: I78dc433a3782b48155ab293cb5afe90b3bc0ef1f

postgresql/templates/monitoring/prometheus/exporter-configmap-etc.yaml

@@ -0,0 +1,27 @@
+{{/*
+Copyright 2017 The Openstack-Helm Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/}}
+
+{{- if and .Values.manifests.monitoring.prometheus.configmap_etc .Values.monitoring.prometheus.enabled }}
+{{- $envAll := . }}
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: postgresql-exporter-etc
+type: Opaque
+data:
+{{- include "helm-toolkit.snippets.values_template_renderer" (dict "envAll" $envAll "template" .Values.conf.exporter.queries "key" "queries.yaml" "format" "Secret") | indent 2 }}
+{{- end }}

postgresql/templates/monitoring/prometheus/exporter-deployment.yaml

@@ -47,6 +47,8 @@ spec:
 {{ tuple $envAll "prometheus_postgresql_exporter" | include "helm-toolkit.snippets.image" | indent 10 }}
 {{ tuple $envAll $envAll.Values.pod.resources.prometheus_postgresql_exporter | include "helm-toolkit.snippets.kubernetes_resources" | indent 10 }}
 {{ dict "envAll" $envAll "application" "prometheus_postgresql_exporter" "container" "postgresql_exporter" | include "helm-toolkit.snippets.kubernetes_container_security_context" | indent 10 }}
+          args:
+            - "--extend.query-path=/queries.yaml"
           ports:
             - name: metrics
               containerPort: {{ tuple "prometheus_postgresql_exporter" "internal" "metrics" . | include "helm-toolkit.endpoints.endpoint_port_lookup" }}
@@ -56,4 +58,13 @@ spec:
                 secretKeyRef:
                   name: {{ .Values.secrets.postgresql.exporter }}
                   key: DATA_SOURCE_NAME
+          volumeMounts:
+            - name: postgresql-exporter-etc
+              mountPath: /queries.yaml
+              subPath: queries.yaml
+      volumes:
+      - name: postgresql-exporter-etc
+        secret:
+          secretName: postgresql-exporter-etc
+          defaultMode: 0444
 {{- end }}

postgresql/values.yaml

@@ -354,6 +354,25 @@ conf:
     base_path: /var/backup
     days_of_backup_to_keep: 3
     pg_dumpall_options: null
+  exporter:
+    queries:
+      pg_replication:
+        query: "SELECT EXTRACT(epoch FROM (now() - pg_last_xact_replay_timestamp()))::int AS lag, CASE WHEN pg_is_in_recovery() THEN 1 ELSE 0 END AS is_replica"
+        master: true
+        metrics:
+          - lag:
+              usage: "GAUGE"
+              description: "Replication lag behind master in seconds"
+          - is_replica:
+              usage: "GAUGE"
+              description: "Indicates if this host is a replica"
+      pg_postmaster:
+        query: "SELECT pg_postmaster_start_time as start_time_seconds from pg_postmaster_start_time()"
+        master: true
+        metrics:
+          - start_time_seconds:
+              usage: "GAUGE"
+              description: "Time at which postmaster started"
 
 secrets:
   pki:
@@ -456,6 +475,7 @@ manifests:
   monitoring:
     prometheus:
       configmap_bin: true
+      configmap_etc: true
       deployment_exporter: true
       job_user_create: true
       secret_etc: true