From 07a965f4d5f1e399667ccbeaad3bfe78a2c31a43 Mon Sep 17 00:00:00 2001
From: Andreas Thaler <andreas.thaler01@sap.com>
Date: Tue, 24 Oct 2023 13:53:33 +0200
Subject: [PATCH] Add default persistence settings to prometheus example (#272)

* Add minimalistic persistence settings to prometheus example

* fix

* fix
---
 kiali/README.md        |  2 +-
 prometheus/README.md   |  2 ++
 prometheus/values.yaml | 50 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/kiali/README.md b/kiali/README.md
index 132b9065..11811c57 100644
--- a/kiali/README.md
+++ b/kiali/README.md
@@ -81,7 +81,7 @@ To see the service communication visualized in Kiali, follow the instructions in
 
 If you use [Jaeger](https://www.jaegertracing.io/) for distributed tracing, Kiali can use your Jaeger instance to [provide traces](https://kiali.io/docs/features/tracing/).
 
-For integration instructions, read [Kiali: Jaeger configuration](https://kiali.io/docs/configuration/p8s-jaeger-grafana/jaeger/).
+For integration instructions, read [Kiali: Jaeger configuration](https://kiali.io/docs/configuration/p8s-jaeger-grafana/tracing/jaeger/).
 
 ### Integrate Grafana
 
diff --git a/prometheus/README.md b/prometheus/README.md
index f8d1c3e7..8bdb6c2b 100644
--- a/prometheus/README.md
+++ b/prometheus/README.md
@@ -59,6 +59,8 @@ The provided `values.yaml` covers the following adjustments:
 - Parallel operation to a Kyma monitoring stack
 - Client certificate injection to support scraping of workload secured with Istio strict mTLS
 - Active scraping of workload annotated with prometheus.io/scrape
+- Basic configuration of data persistence with retention
+- Basic resource limits for involved components
 
 ### Activate scraping of Istio metrics & Grafana dashboards
 
diff --git a/prometheus/values.yaml b/prometheus/values.yaml
index 4f3e610f..b18b20e0 100644
--- a/prometheus/values.yaml
+++ b/prometheus/values.yaml
@@ -7,6 +7,15 @@ prometheusOperator:
   kubeletService:
     enabled: false
 
+  # Define resource limits
+  resources:
+    requests:
+      cpu: "10m"
+      memory: "128Mi"
+    limits:
+      cpu: "500m"
+      memory: "1Gi"
+
 # change the port of the node-exporter to be different from the one used by the Kyma monitoring stack
 prometheus-node-exporter:
   service:
@@ -19,6 +28,15 @@ prometheus-node-exporter:
 kube-state-metrics:
   prometheusScrape: false
 
+  # Define resource limits
+  resources:
+    requests:
+      cpu: "10m"
+      memory: "128Mi"
+    limits:
+      cpu: "500m"
+      memory: "2Gi"
+
 ####### This block disables control plane components which are not reachable from within the Gardener data plane
 
 # Disable scraping of etcd
@@ -62,6 +80,30 @@ prometheus:
       - mountPath: /etc/prometheus/secrets/istio.default/
         name: istio-certs
 
+####### This block configures data retention and persistence
+    # How long to retain metrics
+    retention: 30d
+
+    # Maximum size of metrics
+    retentionSize: 25GB
+
+    # Use a persistent volume for durable storage of data
+    storageSpec:
+      volumeClaimTemplate:
+        spec:
+          resources:
+            requests:
+              storage: 30Gi
+    
+    # Define resource limits
+    resources:
+      limits:
+        cpu: 1000m
+        memory: 4Gi
+      requests:
+        cpu: 125m
+        memory: 256m
+
 ####### This block is needed to also use ServiceMonitors, which are not deployed as part of the chart
 
     # Disable required Helm release labels on ServiceMonitors
@@ -185,6 +227,7 @@ prometheus:
             action: replace
             target_label: node
 
+# Configures grafana with istio sidecar and alertmanage as additional datasource
 grafana:
   additionalDataSources:
     - name: Alertmanager
@@ -201,3 +244,10 @@ grafana:
       runAsUser: 1337
   podLabels:
     sidecar.istio.io/inject: "true"
+  serviceMonitor:
+    scheme: https
+    tlsConfig:
+      caFile: /etc/prometheus/secrets/istio.default/root-cert.pem
+      certFile: /etc/prometheus/secrets/istio.default/cert-chain.pem
+      insecureSkipVerify: true
+      keyFile: /etc/prometheus/secrets/istio.default/key.pem