feat: added service monitor for cert-manager (prometheus)

roles/kubernetes/cert-manager/defaults/main.yml

@@ -1,5 +1,7 @@
 ---
 
+k8s_prometheus_helm__name: "prometheus"
+
 k8s_certmanager_helm__chart_ref: cert-manager
 k8s_certmanager_helm__chart_repo_url: https://charts.jetstack.io
 k8s_certmanager_helm__chart_version: v1.5.4
@@ -8,6 +10,13 @@ k8s_certmanager_helm__release_namespace: cert-manager
 k8s_certmanager_helm__release_values:
   installCRDs: true
   webhook.timeoutSeconds: 4
+  prometheus:
+    enabled: true
+    servicemonitor:
+      enabled: true
+      namespace: cert-manager
+      labels:
+        release: "{{ k8s_prometheus_helm__name }}"
 
 k8s_certmanager_helm__cluster_issuers:
   prod: