[COMMON] Add prometheus service monitor template

Add prometheus service monitor template to common charts so that components
can reuse it to enable scraping of their metrics by prometheus.

Issue-ID: OOM-2710
Signed-off-by: Marat Salakhutdinov <marat.salakhutdinov@bell.ca>
Change-Id: Ifa8da676dec05192c518ba97208df60e5ec46f55

1 files changed, 166 insertions, 0 deletions

diff --git a/kubernetes/common/common/templates/_serviceMonitor.tpl b/kubernetes/common/common/templates/_serviceMonitor.tpl
new file mode 100644
index 0000000000..eb6c047c2f
--- /dev/null
+++ b/kubernetes/common/common/templates/_serviceMonitor.tpl
@@ -0,0 +1,166 @@
+{{/*
+# Copyright © 2021 Bell Canada
+#
+# 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.
+*/}}
+{{/*
+  Resolve the name of a chart's serviceMonitor.
+
+  The default will be the chart name (or $dot.Values.nameOverride if set).
+  And the use of .Values.metrics.serviceMonitor.name overrides all.
+
+  - .Values.metrics.serviceMonitor.name: override default serviceMonitor (ie. chart) name
+  Example values file addition:
+  metrics:
+    serviceMonitor:
+      enabled: true
+      port: blueprints-processor-http
+      ## specify target port if name is not given to the port in the service definition
+      ##
+      # targetPort: 8080
+      path: /metrics
+      basicAuth:
+        enabled: false
+        externalSecretName: mysecretname
+        externalSecretUserKey: login
+        externalSecretPasswordKey: password
+
+      ## Namespace in which Prometheus is running
+      ##
+      # namespace: monitoring
+
+      ## Interval at which metrics should be scraped.
+      ## ref: https://github.com/coreos/prometheus-operator/blob/master/Documentation/api.md#endpoint
+      ##
+      # interval: 60s
+
+      ## Timeout after which the scrape is ended
+      ## ref: https://github.com/coreos/prometheus-operator/blob/master/Documentation/api.md#endpoint
+      ##
+      # scrapeTimeout: 10s
+
+      ## ServiceMonitor selector labels
+      ## ref: https://github.com/bitnami/charts/tree/master/bitnami/prometheus-operator#prometheus-configuration
+      ##
+      selector:
+        app: '{{ include "common.name" . }}'
+        chart: '{{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}'
+        release: '{{ include "common.release" . }}'
+        heritage: '{{ .Release.Service }}'
+
+      ## RelabelConfigs to apply to samples before scraping
+      ## ref: https://github.com/coreos/prometheus-operator/blob/master/Documentation/api.md#relabelconfig
+      ## Value is evalued as a template
+      ##
+      relabelings: []
+
+      ## MetricRelabelConfigs to apply to samples before ingestion
+      ## ref: https://github.com/coreos/prometheus-operator/blob/master/Documentation/api.md#relabelconfig
+      ## Value is evalued as a template
+      ##
+      metricRelabelings: []
+      #  - sourceLabels:
+      #      - "__name__"
+      #    targetLabel: "__name__"
+      #    action: replace
+      #    regex: '(.*)'
+      #    replacement: 'example_prefix_$1'
+
+*/}}
+{{/*
+  Expand the serviceMonitor name for a chart.
+*/}}
+{{- define "common.serviceMonitorName" -}}
+  {{- $name := default .Chart.Name .Values.nameOverride -}}
+  {{- default $name .Values.metrics.serviceMonitor.name | trunc 63 | trimSuffix "-" -}}
+{{- end -}}
+
+{{/* Define the metadata of serviceMonitor
+     The function takes from one to four arguments (inside a dictionary):
+     - .dot : environment (.)
+     - .suffix : a string which will be added at the end of the name (with a '-').
+     - .annotations: the annotations to add
+     - .labels : labels to add
+     Usage example:
+      {{ include "common.serviceMonitorMetadata" ( dict "suffix" "myService" "dot" .) }}
+      {{ include "common.serviceMonitorMetadata" ( dict "annotations" .Values.metrics.serviceMonitor.annotation "dot" .) }}
+*/}}
+
+{{- define "common.serviceMonitorMetadata" -}}
+{{-   $dot := default . .dot -}}
+{{-   $annotations := default "" .annotations -}}
+{{-   $labels := default (dict) .labels -}}
+{{- if $annotations -}}
+annotations:
+{{    include "common.tplValue" (dict "value" $annotations "context" $dot) | indent 2 }}
+{{- end }}
+name: {{ include "common.serviceMonitorName" $dot }}
+{{- if $dot.Values.metrics.serviceMonitor.namespace }}
+namespace: {{ $dot.Values.metrics.serviceMonitor.namespace }}
+{{- else }}
+namespace: {{ include "common.namespace" $dot }}
+{{- end }}
+labels: {{- include "common.labels" (dict "labels" $labels "dot" $dot) | nindent 2 }}
+{{- end -}}
+
+{{/*
+    Create service monitor template
+*/}}
+{{- define "common.serviceMonitor" -}}
+{{-   $dot := default . .dot -}}
+{{-   $labels := default (dict) .labels -}}
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+{{- include "common.serviceMonitorMetadata" $dot | nindent 2 }}
+spec:
+  endpoints:
+  - path: {{ default "/metrics" $dot.Values.metrics.serviceMonitor.path }}
+    {{- if $dot.Values.metrics.serviceMonitor.port }}
+    port: {{ $dot.Values.metrics.serviceMonitor.port }}
+    {{- else if $dot.Values.metrics.serviceMonitor.targetPort }}
+    targetPort: {{ $dot.Values.metrics.serviceMonitor.targetPort }}
+    {{- else }}
+    port: metrics
+    {{- end }}
+    {{- if $dot.Values.metrics.serviceMonitor.basicAuth.enabled }}
+    basicAuth:
+      username:
+        key: {{ $dot.Values.metrics.serviceMonitor.basicAuth.externalSecretUserKey }}
+        name: {{ $dot.Values.metrics.serviceMonitor.basicAuth.externalSecretName }}
+      password:
+        key: {{ $dot.Values.metrics.serviceMonitor.basicAuth.externalSecretPasswordKey }}
+        name: {{ $dot.Values.metrics.serviceMonitor.basicAuth.externalSecretName }}
+    {{- end }}
+    {{- if $dot.Values.metrics.serviceMonitor.interval }}
+    interval: {{ $dot.Values.metrics.serviceMonitor.interval }}
+    {{- end }}
+    {{- if $dot.Values.metrics.serviceMonitor.scrapeTimeout }}
+    scrapeTimeout: {{ $dot.Values.metrics.serviceMonitor.scrapeTimeout }}
+    {{- end }}
+    {{- if $dot.Values.metrics.serviceMonitor.relabelings }}
+    relabelings: {{- include "common.tplValue" ( dict "value" $dot.Values.metrics.serviceMonitor.relabelings "context" $dot) | nindent 6 }}
+    {{- end }}
+    {{- if $dot.Values.metrics.serviceMonitor.metricRelabelings }}
+    metricRelabelings: {{- include "common.tplValue" ( dict "value" $dot.Values.metrics.serviceMonitor.metricRelabelings "context" $dot) | nindent 6 }}
+    {{- end }}
+  namespaceSelector:
+    matchNames:
+    - {{ include "common.namespace" $dot }}
+  selector:
+    {{- if $dot.Values.metrics.serviceMonitor.selector }}
+    matchLabels: {{- include "common.tplValue" ( dict "value" $dot.Values.metrics.serviceMonitor.selector "context" $dot) | nindent 6 }}
+    {{- else }}
+    matchLabels: {{- include "common.labels" (dict "labels" $labels "dot" $dot) | nindent 6 }}
+    {{- end }}
+{{- end -}}