Add prometheus tls example (#539)

* Add prom tls example

Author: Gsantomaggio

docs/examples/prometheus/README.md

@@ -9,3 +9,9 @@ kubectl apply -f rabbitmq-podmonitor.yaml
 
 Alternatively, if you deployed the Prometheus Operator via the [kube-prometheus-stack](https://github.com/prometheus-community/helm-charts/tree/main/charts/kube-prometheus-stack) Helm chart,
 set the values in [kube-prometheus-stack-values.yaml.example](kube-prometheus-stack-values.yaml.example) when installing / upgrading the Helm chart.
+
+---
+## TLS Endpoints
+
+With `TLS` enabled you should use `-tls` files to deploy the secure prometheus endpoints. 
+_Note_: The standard Prometheus (15692) port is disabled with the option `disableNonTLSListeners=true`.  

docs/examples/prometheus/kube-prometheus-stack-values-tls.yaml.example

@@ -0,0 +1,14 @@
+---
+prometheus:
+  additionalPodMonitors:
+   - name: rabbitmq
+     podMetricsEndpoints:
+     - port: prometheus-tls
+       scheme: https
+       tlsConfig:
+           insecureSkipVerify: true
+     selector:
+       matchLabels:
+         app.kubernetes.io/component: rabbitmq
+     namespaceSelector:
+       any: true

docs/examples/prometheus/rabbitmq-podmonitor-tls.yaml

@@ -0,0 +1,15 @@
+---
+apiVersion: monitoring.coreos.com/v1
+kind: PodMonitor
+metadata:
+  name: rabbitmq
+spec:
+  podMetricsEndpoints:
+  - interval: 15s
+    scheme: https
+    port: prometheus-tls
+  selector:
+    matchLabels:
+      app.kubernetes.io/component: rabbitmq
+  namespaceSelector:
+    any: true