[prometheus-adapter] Add a pod disruption budget (prometheus-communit…

…y#143)

Signed-off-by: Ahmed Nasir <ahmednasir91@gmail.com>

charts/prometheus-adapter/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: v1
 name: prometheus-adapter
-version: 2.6.2
+version: 2.7.0
 appVersion: v0.7.0
 description: A Helm chart for k8s prometheus adapter
 home: https://github.com/DirectXMan12/k8s-prometheus-adapter

charts/prometheus-adapter/templates/custom-metrics-apiserver-pdb.yaml

@@ -0,0 +1,22 @@
+{{- if .Values.podDisruptionBudget.enabled }}
+apiVersion: policy/v1beta1
+kind: PodDisruptionBudget
+metadata:
+  name: {{ template "k8s-prometheus-adapter.fullname" . }}
+  labels:
+    app: {{ template "k8s-prometheus-adapter.name" . }}
+    chart: {{ template "k8s-prometheus-adapter.chart" . }}
+    release: {{ .Release.Name }}
+    heritage: {{ .Release.Service }}
+spec:
+  {{- if .Values.podDisruptionBudget.minAvailable }}
+  minAvailable: {{ .Values.podDisruptionBudget.minAvailable }}
+  {{- end  }}
+  {{- if .Values.podDisruptionBudget.maxUnavailable }}
+  maxUnavailable: {{ .Values.podDisruptionBudget.maxUnavailable }}
+  {{- end  }}
+  selector:
+    matchLabels:
+      app: {{ template "k8s-prometheus-adapter.name" . }}
+      release: {{ .Release.Name }}
+{{- end }}

charts/prometheus-adapter/values.yaml

@@ -143,3 +143,10 @@ hostNetwork:
   # API server unable to communicate with metrics-server. As an example, this is required
   # if you use Weave network on EKS
   enabled: false
+
+podDisruptionBudget:
+  # Specifies if PodDisruptionBudget should be enabled
+  # When enabled, minAvailable or maxUnavailable should also be defined.
+  enabled: false
+  minAvailable:
+  maxUnavailable: 1