Add instructions to add Prometheus exporter annotations

Signed-off-by: juan131 <juan@bitnami.com>

bitnami/minio/README.md

@@ -147,6 +147,22 @@ $ helm install --name my-release bitnami/minio --set mode=distributed --set stat
 
 > Note: that the number of replicas must even, greater than 4 and lower than 32
 
+## Prometheus exporter
+
+MinIO exports Prometheus metrics at `/minio/prometheus/metrics`. To allow Prometheus collecting your MinIO metrics, modify the `values.yaml` adding the corresponding annotations:
+
+```diff
+service:
+  ...
+-  annotations: {}
++  annotations:
++    prometheus.io/scrape: "true"
++    prometheus.io/path: "/minio/prometheus/metrics"
++    prometheus.io/port: "9000"
+```
+
+> Find more information about MinIO metrics at https://docs.min.io/docs/how-to-monitor-minio-using-prometheus.html
+
 ## Production settings
 
 The [values-production.yaml](values-production.yaml) file consists a configuration to deploy a high-available MinIO deployment distributed mode for production environments. We recommend that you base your production configuration on this template and adjust the parameters appropriately.

bitnami/minio/templates/statefulset.yaml

@@ -17,7 +17,7 @@ spec:
       app.kubernetes.io/instance: {{ .Release.Name }}
   serviceName: {{ include "minio.fullname" . }}-headless
   replicas: {{ .Values.statefulset.replicaCount }}
-  podManagementPolicy: {{ .Values.statefulset.podManagementPolicy | quote }}
+  podManagementPolicy: {{ .Values.statefulset.podManagementPolicy }}
   updateStrategy:
     type: {{ .Values.statefulset.updateStrategy }}
     {{- if (eq "Recreate" .Values.statefulset.updateStrategy) }}

bitnami/minio/values-production.yaml

@@ -198,7 +198,10 @@ service:
   ## set the LoadBalancer service type to internal only.
   ## ref: https://kubernetes.io/docs/concepts/services-networking/service/#internal-load-balancer
   ##
-  annotations: {}
+  annotations:
+    prometheus.io/scrape: "true"
+    prometheus.io/path: "/minio/prometheus/metrics"
+    prometheus.io/port: "9000"
 
   ## loadBalancerIP for the PrestaShop Service (optional, cloud specific)
   ## ref: http://kubernetes.io/docs/user-guide/services/#type-loadbalancer