OBSDOCS-2004 scrape targets in multiple namespaces

modules/monitoring-scrape-targets-in-multiple-namespaces.adoc

@@ -0,0 +1,206 @@
+// Module included in the following assemblies:
+//
+// * observability/cluster-observability-operator/configuring-the-cluster-observability-operator-to-monitor-a-service.adoc
+
+:_mod-docs-content-type: PROCEDURE
+[id="monitoring-scrape-targets-in-multiple-namespaces_{context}"]
+= Scrape targets in multiple namespaces
+
+To scrape targets in multiple namespaces, set the namespace and resource selector in the `MonitoringStack` object.
+
+.Prerequisites
+
+* You have access to the cluster as a user with the `cluster-admin` cluster role or as a user with administrative permissions for the namespace.
+* You have installed the {coo-full}.
+
+.Procedure
+
+. Deploy the following namespace object and `MonitoringStack` YAML file:
++
+.Example `MonitoringStack`
+[source,yaml]
+----
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: ns1-coo
+  labels:
+    monitoring.rhobs/stack: multi-ns
+---
+apiVersion: monitoring.rhobs/v1alpha1
+kind: MonitoringStack
+metadata:
+  name: example-coo-monitoring-stack
+  namespace: ns1-coo
+spec:
+  logLevel: debug
+  retention: 1d
+  resourceSelector:
+      matchLabels:
+        k8s-app: prometheus-coo-example-monitor
+  namespaceSelector:
+      matchLabels:
+        monitoring.rhobs/stack: multi-ns
+----
+
+. Deploy a sample application in the namespace `ns1-coo`, with an alert that is always firing:
++
+[source,yaml]
+----
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  labels:
+    app: prometheus-coo-example-app
+  name: prometheus-coo-example-app
+  namespace: ns1-coo
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: prometheus-coo-example-app
+  template:
+    metadata:
+      labels:
+        app: prometheus-coo-example-app
+    spec:
+      containers:
+      - image: ghcr.io/rhobs/prometheus-example-app:0.4.2
+        imagePullPolicy: IfNotPresent
+        name: prometheus-coo-example-app
+---
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app: prometheus-coo-example-app
+  name: prometheus-coo-example-app
+  namespace: ns1-coo
+spec:
+  ports:
+  - port: 8080
+    protocol: TCP
+    targetPort: 8080
+    name: web
+  selector:
+    app: prometheus-coo-example-app
+  type: ClusterIP
+---
+apiVersion: monitoring.rhobs/v1
+kind: ServiceMonitor
+metadata:
+  labels:
+    k8s-app: prometheus-coo-example-monitor
+  name: prometheus-coo-example-monitor
+  namespace: ns1-coo
+spec:
+  endpoints:
+  - interval: 30s
+    port: web
+    scheme: http
+  selector:
+    matchLabels:
+      app: prometheus-coo-example-app
+---
+apiVersion: monitoring.rhobs/v1
+kind: PrometheusRule
+metadata:
+  name: example-alert
+  namespace: ns1-coo
+  labels:
+    k8s-app: prometheus-coo-example-monitor
+spec:
+  groups:
+  - name: example
+    rules:
+    - alert: VersionAlert
+      for: 1m
+      expr: version{job="prometheus-coo-example-app"} > 0
+      labels:
+        severity: warning
+----
+
+. Deploy the same example application in another namespace labeled with `monitoring.rhobs/stack: multi-ns`:
++
+[source,yaml]
+----
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: ns2-coo
+  labels:
+    monitoring.rhobs/stack: multi-ns
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  labels:
+    app: prometheus-coo-example-app
+  name: prometheus-coo-example-app
+  namespace: ns2-coo
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: prometheus-coo-example-app
+  template:
+    metadata:
+      labels:
+        app: prometheus-coo-example-app
+    spec:
+      containers:
+      - image: ghcr.io/rhobs/prometheus-example-app:0.4.2
+        imagePullPolicy: IfNotPresent
+        name: prometheus-coo-example-app
+---
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app: prometheus-coo-example-app
+  name: prometheus-coo-example-app
+  namespace: ns2-coo
+spec:
+  ports:
+  - port: 8080
+    protocol: TCP
+    targetPort: 8080
+    name: web
+  selector:
+    app: prometheus-coo-example-app
+  type: ClusterIP
+---
+apiVersion: monitoring.rhobs/v1
+kind: ServiceMonitor
+metadata:
+  labels:
+    k8s-app: prometheus-coo-example-monitor
+  name: prometheus-coo-example-monitor
+  namespace: ns2-coo
+spec:
+  endpoints:
+  - interval: 30s
+    port: web
+    scheme: http
+  selector:
+    matchLabels:
+      app: prometheus-coo-example-app
+----
+
+.Verification
+
+. Verify that the Prometheus instance adds new targets and that the alert are firing. Use a port-forward command to expose the Prometheus or the Alertmanager user interface that has been deployed by the `Monitoringstack` instance.
++
+.Prometheus
+[source,terminal]
+----
+$ oc port-forward -n ns1-coo pod/prometheus-example-coo-monitoring-stack-0 9090
+----
++
+.Alertmanager
+[source,terminal]
+----
+$ oc port-forward -n ns1-coo pod/alertmanager-example-coo-monitoring-stack-0 9093
+----
+
+. Verify that the targets are being scraped and that the alerts are firing by browsing to `http://localhost:9090/targets` or `http://localhost:9093/#/alerts`.

observability/cluster_observability_operator/configuring-the-cluster-observability-operator-to-monitor-a-service.adoc

@@ -23,6 +23,8 @@ include::modules/monitoring-specifying-how-a-service-is-monitored-by-cluster-obs
 // Create a MonitoringStack object to discover the service monitor
 include::modules/monitoring-creating-a-monitoringstack-object-for-cluster-observability-operator.adoc[leveloffset=+1]
 
-// Validate a MonitoringStack 
+// Validate a MonitoringStack
 include::modules/monitoring-validating-a-monitoringstack-for-cluster-observability-operator.adoc[leveloffset=+1]
 
+// Scrape targets in multiple namespaces
+include::modules/monitoring-scrape-targets-in-multiple-namespaces.adoc[leveloffset=+1]