Namespace support in prometheus rule (#2931)

* helm templating and test cases for namespace support in prometheus rule crd

* updated prometheus rules

---------

Co-authored-by: Yash Jagdale <yash@databahn.ai>
Co-authored-by: Roman Gershman <roman@dragonflydb.io>

.gitignore

@@ -16,3 +16,4 @@ genfiles/*
 _deps
 releases
 .DS_Store
+.idea/*

contrib/charts/dragonfly/ci/prometheusrules-values.golden.yaml

@@ -0,0 +1,145 @@
+---
+# Source: dragonfly/templates/serviceaccount.yaml
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: test-dragonfly
+  namespace: default
+  labels:
+    app.kubernetes.io/name: dragonfly
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/version: "v1.17.1"
+    app.kubernetes.io/managed-by: Helm
+---
+# Source: dragonfly/templates/metrics-service.yaml
+apiVersion: v1
+kind: Service
+metadata:
+  name: test-dragonfly-metrics
+  namespace: default
+  labels:
+    app.kubernetes.io/name: dragonfly
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/version: "v1.17.1"
+    app.kubernetes.io/managed-by: Helm
+    type: metrics
+spec:
+  type: ClusterIP
+  ports:
+    - name: metrics
+      port: 6379
+      targetPort: 6379
+      protocol: TCP
+  selector:
+    app.kubernetes.io/name: dragonfly
+    app.kubernetes.io/instance: test
+---
+# Source: dragonfly/templates/service.yaml
+apiVersion: v1
+kind: Service
+metadata:
+  name: test-dragonfly
+  namespace: default
+  labels:
+    app.kubernetes.io/name: dragonfly
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/version: "v1.17.1"
+    app.kubernetes.io/managed-by: Helm
+spec:
+  type: ClusterIP
+  ports:
+    - port: 6379
+      targetPort: dragonfly
+      protocol: TCP
+      name: dragonfly
+  selector:
+    app.kubernetes.io/name: dragonfly
+    app.kubernetes.io/instance: test
+---
+# Source: dragonfly/templates/deployment.yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: test-dragonfly
+  namespace: default
+  labels:
+    app.kubernetes.io/name: dragonfly
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/version: "v1.17.1"
+    app.kubernetes.io/managed-by: Helm
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: dragonfly
+      app.kubernetes.io/instance: test
+  template:
+    metadata:
+      annotations:
+      labels:
+        app.kubernetes.io/name: dragonfly
+        app.kubernetes.io/instance: test
+    spec:
+      serviceAccountName: test-dragonfly
+      containers:
+        - name: dragonfly
+          image: "docker.dragonflydb.io/dragonflydb/dragonfly:v1.17.1"
+          imagePullPolicy: IfNotPresent
+          ports:
+            - name: dragonfly
+              containerPort: 6379
+              protocol: TCP
+          livenessProbe:
+            exec:
+              command:
+              - /bin/sh
+              - /usr/local/bin/healthcheck.sh
+            failureThreshold: 3
+            initialDelaySeconds: 10
+            periodSeconds: 10
+            successThreshold: 1
+            timeoutSeconds: 5
+          readinessProbe:
+            exec:
+              command:
+              - /bin/sh
+              - /usr/local/bin/healthcheck.sh
+            failureThreshold: 3
+            initialDelaySeconds: 10
+            periodSeconds: 10
+            successThreshold: 1
+            timeoutSeconds: 5
+          args:
+            - "--alsologtostderr"
+          resources:
+            limits: {}
+            requests: {}
+---
+# Source: dragonfly/templates/servicemonitor.yaml
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  name: test-dragonfly-metrics
+  namespace: default
+  labels:
+    app.kubernetes.io/name: dragonfly
+    app.kubernetes.io/instance: test
+    app.kubernetes.io/version: "v1.17.1"
+    app.kubernetes.io/managed-by: Helm
+spec:
+  endpoints:
+    - interval: 10s
+      scrapeTimeout: 10s
+      honorLabels: true
+      port: metrics
+      path: /metrics
+      scheme: http
+  jobLabel: "test"
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: dragonfly
+      app.kubernetes.io/instance: test
+      type: metrics
+  namespaceSelector:
+    matchNames:
+      - default

contrib/charts/dragonfly/ci/prometheusrules-values.yaml

@@ -0,0 +1,16 @@
+serviceMonitor:
+  enabled: true
+prometheusRule:
+  enabled: true
+  namespace: default
+  spec:
+    - alert: RedisDown
+      expr: absent(dragonfly_master > 0)
+      for: 0m
+      labels:
+        severity: critical
+      annotations:
+        summary: Redis instance is down
+        description: >
+          "Redis instance is down"
+        runbook_url: "https://octopus.com/docs/runbooks/runbook-examples"

contrib/charts/dragonfly/templates/prometheusrule.yaml

@@ -3,7 +3,7 @@ apiVersion: monitoring.coreos.com/v1
 kind: PrometheusRule
 metadata:
   name: {{ template "dragonfly.fullname" . }}-metrics
-  namespace: {{ .Release.Namespace }}
+  namespace: {{ .Values.prometheusRule.namespace | default .Release.Namespace }}
   labels:
     {{- include "dragonfly.labels" . | nindent 4 }}
 spec: