[kube-prometheus-stack] Add exemplars related settings (#2332)

* add exemplars related settings, increase chart version

Signed-off-by: Fausto David Suarez Rosario <faustodavid@hotmail.com>

* Update charts/kube-prometheus-stack/values.yaml

comment exemplars.maxSize

Co-authored-by: André Bauer <monotek@users.noreply.github.com>
Signed-off-by: Fausto David Suarez Rosario <faustodavid@hotmail.com>

* increase chart version

Signed-off-by: Fausto David Suarez Rosario <faustodavid@hotmail.com>

* fix comment, add code suggestions.

Signed-off-by: Fausto David Suarez Rosario <faustodavid@hotmail.com>

* remove trailing spaces

Signed-off-by: Fausto David Suarez Rosario <faustodavid@hotmail.com>

* Update charts/kube-prometheus-stack/Chart.yaml

Signed-off-by: André Bauer <monotek@users.noreply.github.com>

Co-authored-by: André Bauer <monotek@users.noreply.github.com>

charts/kube-prometheus-stack/Chart.yaml

@@ -22,7 +22,7 @@ name: kube-prometheus-stack
 sources:
   - https://github.com/prometheus-community/helm-charts
   - https://github.com/prometheus-operator/kube-prometheus
-version: 39.3.0
+version: 39.4.0
 appVersion: 0.58.0
 kubeVersion: ">=1.16.0-0"
 home: https://github.com/prometheus-operator/kube-prometheus

charts/kube-prometheus-stack/templates/prometheus/prometheus.yaml

@@ -85,6 +85,10 @@ spec:
   web:
 {{ toYaml .Values.prometheus.prometheusSpec.web | indent 4 }}
 {{- end }}
+{{- if .Values.prometheus.prometheusSpec.exemplars }}
+  exemplars:
+  {{ toYaml .Values.prometheus.prometheusSpec.exemplars | indent 4 }}
+{{- end }}
 {{- if .Values.prometheus.prometheusSpec.enableFeatures }}
   enableFeatures:
 {{- range $enableFeatures := .Values.prometheus.prometheusSpec.enableFeatures }}

charts/kube-prometheus-stack/values.yaml

@@ -2287,6 +2287,14 @@ prometheus:
     ## ref: https://github.com/prometheus-operator/prometheus-operator/blob/main/Documentation/api.md#webtlsconfig
     web: {}
 
+    ## Exemplars related settings that are runtime reloadable.
+    ## It requires to enable the exemplar storage feature to be effective.
+    exemplars: ""
+      ## Maximum number of exemplars stored in memory for all series.
+      ## If not set, Prometheus uses its default value.
+      ## A value of zero or less than zero disables the storage.
+      # maxSize: 100000
+
     # EnableFeatures API enables access to Prometheus disabled features.
     # ref: https://prometheus.io/docs/prometheus/latest/disabled_features/
     enableFeatures: []