charts/libvirt: add Prometheus libvirt exporter support

- Introduce ghcr.io/inovex/prometheus-libvirt-exporter image for libvirt metrics
- Compatible with Kolla-Ansible deployments for consistent monitoring

Change-Id: I6516693c989bfaac4d67d86e6b0b6144335eb2b7
Signed-off-by: Saeed Padari <sam137115@gmail.com>

libvirt/releasenotes/notes/libvirt-339936ca478fbf50.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    Make exporter container args configurable in values to make it possible to use
+    ghcr.io/inovex/prometheus-libvirt-exporter image which assumes
+    having no additional args.
+...

libvirt/templates/daemonset-libvirt.yaml

@@ -295,13 +295,19 @@ spec:
               readOnly: true
             {{- end }}
 {{ if $mounts_libvirt.volumeMounts }}{{ toYaml $mounts_libvirt.volumeMounts | indent 12 }}{{ end }}
-        {{- if .Values.pod.sidecars.libvirt_exporter }}
+        {{- if .Values.pod.sidecars.libvirt_exporter.enabled }}
         - name: libvirt-exporter
 {{ tuple $envAll "libvirt_exporter" | include "helm-toolkit.snippets.image" | indent 10 }}
 {{ tuple $envAll $envAll.Values.pod.resources.libvirt_exporter | include "helm-toolkit.snippets.kubernetes_resources" | indent 10 }}
 {{ dict "envAll" $envAll "application" "libvirt" "container" "libvirt_exporter" | include "helm-toolkit.snippets.kubernetes_container_security_context" | indent 10 }}
+          {{- with .Values.pod.sidecars.libvirt_exporter }}
+            {{- if and (hasKey . "args") (gt (len .args) 0) }}
           args:
-            - "--libvirt.nova"
+              {{- range .args }}
+            - {{ . | quote }}
+              {{- end }}
+            {{- end }}
+          {{- end }}
           ports:
             - name: metrics
               protocol: TCP
@@ -310,10 +316,12 @@ spec:
             httpGet:
               path: /
               port: metrics
+              timeoutSeconds: 5
           readinessProbe:
             httpGet:
               path: /
               port: metrics
+              timeoutSeconds: 5
           volumeMounts:
             - name: run
               mountPath: /run

libvirt/templates/pod-monitor.yaml

@@ -0,0 +1,18 @@
+{{- if .Values.manifests.podmonitor -}}
+apiVersion: monitoring.coreos.com/v1
+kind: PodMonitor
+metadata:
+  name: libvirt-exporter
+spec:
+  namespaceSelector:
+    matchNames:
+    - {{ .Release.Namespace }}
+  podMetricsEndpoints:
+  - interval: 10s
+    path: /metrics
+    port: metrics
+    scheme: http
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: libvirt-exporter
+{{- end -}}

libvirt/values.yaml

@@ -291,7 +291,10 @@ pod:
             drop:
               - ALL
   sidecars:
-    libvirt_exporter: false
+    libvirt_exporter:
+      enabled: false
+      args:
+        - "--libvirt.nova"
 
   affinity:
     anti:
@@ -403,6 +406,7 @@ manifests:
   network_policy: false
   role_cert_manager: false
   secret_registry: true
+  podmonitor: false
 
 secrets:
   oci_image_registry:

values_overrides/libvirt/inovex_exporter.yaml

@@ -0,0 +1,13 @@
+---
+# NOTE: Use the inovex exporter image by default since 2026.1 release.
+images:
+  tags:
+    libvirt_exporter: ghcr.io/inovex/prometheus-libvirt-exporter:2.2.0
+pod:
+  sidecars:
+    libvirt_exporter:
+      enabled: true
+      args: []
+manifests:
+  podmonitor: true
+...