Add kube-router configuration to enable metrics exposure (#5416)

inventory/sample/group_vars/k8s-cluster/k8s-net-kube-router.yml

@@ -47,3 +47,12 @@
 
 # Array of common annotations for every node
 # kube_router_annotations_all: []
+
+# Enables scraping kube-router metrics with Prometheus
+# kube_router_enable_metrics: false
+
+# Path to serve Prometheus metrics on
+# kube_router_metrics_path: /metrics
+
+# Prometheus metrics port to use
+# kube_router_metrics_port: 9255

roles/network_plugin/kube-router/defaults/main.yml

@@ -49,3 +49,12 @@ kube_router_annotations_node: []
 
 # Array of common annotations for every node
 kube_router_annotations_all: []
+
+# Enables scraping kube-router metrics with Prometheus
+kube_router_enable_metrics: false
+
+# Path to serve Prometheus metrics on
+kube_router_metrics_path: /metrics
+
+# Prometheus metrics port to use
+kube_router_metrics_port: 9255

roles/network_plugin/kube-router/templates/kube-router.yml.j2

@@ -65,6 +65,12 @@ spec:
       labels:
         k8s-app: kube-router
         tier: node
+      annotations:
+{% if kube_router_enable_metrics %}
+        prometheus.io/path: {{ kube_router_metrics_path }}
+        prometheus.io/port: "{{ kube_router_metrics_port }}"
+        prometheus.io/scrape: "true"
+{% endif %}
     spec:
       priorityClassName: system-cluster-critical
       serviceAccountName: kube-router
@@ -95,6 +101,10 @@ spec:
 {% if kube_router_peer_router_ports %}
         - --peer-router-ports={{ kube_router_peer_router_ports }}
 {% endif %}
+{% if kube_router_enable_metrics %}
+        - --metrics-path={{ kube_router_metrics_path }}
+        - --metrics-port={{ kube_router_metrics_port }}
+{% endif %}
 {% for arg in kube_router_extra_args %}
         - "{{ arg }}"
 {% endfor %}
@@ -129,6 +139,13 @@ spec:
         - name: kubeconfig
           mountPath: /var/lib/kube-router
           readOnly: true
+{% if kube_router_enable_metrics %}
+        ports:
+        - containerPort: {{ kube_router_metrics_port }}
+          hostPort: {{ kube_router_metrics_port }}
+          name: metrics
+          protocol: TCP
+{% endif %}
       initContainers:
       - name: install-cni
         image: {{ busybox_image_repo }}:{{ busybox_image_tag }}