add optional PodDisruptionBudget to helm chart (#515)

* add optional PodDisruptionBudget to helm chart

* address comments

* add back new line - no change to helpers template

* fix silly typo in loki-stack version

production/helm/loki-stack/Chart.yaml

 name: loki-stack
-version: 0.8.1
+version: 0.9.0
 appVersion: 0.0.1
 kubeVersion: "^1.10.0-0"
 description: "Loki: like Prometheus, but for logs."

production/helm/loki/Chart.yaml

 name: loki
-version: 0.7.2
+version: 0.8.0
 appVersion: 0.0.1
 kubeVersion: "^1.10.0-0"
 description: "Loki: like Prometheus, but for logs."

production/helm/loki/templates/_helpers.tpl

@@ -41,4 +41,3 @@ Create the name of the service account
     {{ default "default" .Values.serviceAccount.name }}
 {{- end -}}
 {{- end -}}
-

production/helm/loki/templates/pdb.yaml

+{{- if .Values.podDisruptionBudget -}}
+apiVersion: policy/v1beta1
+kind: PodDisruptionBudget
+metadata:
+  name: {{ template "loki.fullname" . }}
+  app: {{ template "loki.name" . }}
+  heritage: {{ .Release.Service }}
+  release: {{ .Release.Name }}
+  chart: {{ template "loki.chart" . }}
+spec:
+  selector:
+    matchLabels:
+      app: {{ template "loki.name" . }}
+{{ toYaml .Values.podDisruptionBudget | indent 2 }}
+{{- end -}}
\ No newline at end of file

production/helm/loki/values.yaml

@@ -150,3 +150,9 @@ terminationGracePeriodSeconds: 30
 ## Tolerations for pod assignment
 ## ref: https://kubernetes.io/docs/concepts/configuration/taint-and-toleration/
 tolerations: []
+
+# The values to set in the PodDisruptionBudget spec
+# If not set then a PodDisruptionBudget will not be created
+podDisruptionBudget: {}
+# minAvailable: 1
+# maxUnavailable: 1