monitoring - increase scrapeInterval to 120s, better selectors on Agent and memory decrease of agent from 360MB to 228MB

monitoring/prometheus/deploy/helm/04-kubelet.yaml

@@ -4,10 +4,11 @@ kubelet:
   enabled: true
   namespace: kube-system
   serviceMonitor:
-    interval: 30s #WARN: Error on ingesting out-of-order samples. https://github.com/prometheus-community/helm-charts/issues/5483
+    interval: 60s #WARN: Error on ingesting out-of-order samples. https://github.com/prometheus-community/helm-charts/issues/5483
     enabled: true 
     ## Enable scraping /metrics from kubelet's service
     kubelet: true
+    cAdvisor: true
     additionalLabels:
       app.kubernetes.io/name: prometheus-kubelet # !important: selector used by agent