Merge branch '792-increase-grafana-retention-time' into 'master'

Resolve "Increase grafana retention time"

Closes #792

See merge request openappstack/openappstack!409

ansible/roles/apps/templates/settings/prometheus-stack.yaml

@@ -97,10 +97,11 @@ alertmanager:
 
 
 prometheus:
+  # https://github.com/prometheus-community/helm-charts/tree/main/charts/prometheus
   prometheusSpec:
     scrapeInterval: "3m"
     evaluationInterval: "3m"
-    retention: "10d"
+    retention: "30d"
 
 #    replicas: 2
 #    podAntiAffinity: "hard"
@@ -141,6 +142,7 @@ prometheus:
 #
 
 grafana:
+  # https://github.com/grafana/helm-charts/tree/main/charts/grafana
   adminPassword: "{{ grafana_admin_password }}"
   grafana.ini:
     server: