[stable/airflow] Add support for prometheus rules

Signed-off-by: Stijn De Haes <stijndehaes@gmail.com>

stable/airflow/Chart.yaml

@@ -1,6 +1,6 @@
 description: Airflow is a platform to programmatically author, schedule and monitor workflows
 name: airflow
-version: 2.7.1
+version: 2.8.0
 appVersion: 1.10.2
 icon: https://airflow.apache.org/_images/pin_large.png
 home: https://airflow.apache.org/

stable/airflow/README.md

@@ -381,6 +381,9 @@ The following table lists the configurable parameters of the Airflow chart and t
 | `serviceMonitor.interval`                | Interval at which metrics should be scraped             | `30s`                     |
 | `serviceMonitor.path`                    | The path at which the metrics should be scraped         | `/admin/metrics`          |
 | `serviceMonitor.selector`                | label Selector for Prometheus to find ServiceMonitors   | `prometheus: kube-prometheus` |
+| `prometheusRule.enabled`                 | enable prometheus rule                                  | `false`                   |
+| `prometheusRule.groups`                  | define alerting rules                                   | `{}`                      |
+| `prometheusRule.additionalLabels`        | add additional labels to the prometheus rule            | `{}`                      |
 
 
 Full and up-to-date documentation can be found in the comments of the `values.yaml` file.

stable/airflow/templates/prometheus-rule.yaml

@@ -0,0 +1,17 @@
+{{- if .Values.prometheusRule.enabled }}
+apiVersion: monitoring.coreos.com/v1
+kind: PrometheusRule
+metadata:
+  name: {{ template "airflow.fullname" . }}
+  labels:
+    app: {{ template "airflow.name" . }}
+    chart: {{ template "airflow.chart" . }}
+    heritage: {{ .Release.Service }}
+    release: {{ .Release.Name }}
+      {{- if .Values.prometheusRule.additionalLabels }}
+      {{ toYaml .Values.prometheusRule.additionalLabels | indent 4 }}
+    {{- end }}
+spec:
+  groups:
+{{ toYaml .Values.prometheusRule.groups | indent 4 }}
+{{- end }}

stable/airflow/values.yaml

@@ -549,3 +549,17 @@ serviceMonitor:
   ## [Kube Prometheus Selector Label](https://github.com/helm/charts/tree/master/stable/prometheus-operator#exporters)
   selector:
     prometheus: kube-prometheus
+
+# Enable this if you're using https://github.com/coreos/prometheus-operator
+prometheusRule:
+  enabled: false
+  ## Namespace in which the prometheus rule is created
+  # namespace: monitoring
+  ## Define individual alerting rules as required
+  ## ref: https://github.com/coreos/prometheus-operator/blob/master/Documentation/api.md#rulegroup
+  ##      https://prometheus.io/docs/prometheus/latest/configuration/alerting_rules/
+  groups: {}
+
+  ## Used to pass Labels that are used by the Prometheus installed in your cluster to select Prometheus Rules to work with
+  ## ref: https://github.com/coreos/prometheus-operator/blob/master/Documentation/api.md#prometheusspec
+  additionalLabels: {}