conf(ingress-nginx): Add metrics exporter

Enable metrics export for scraping via prometheus. This will allow a
view into application performance and results.

Author: ssoriche

platform/ingress-nginx/kustomization.yaml

@@ -3,6 +3,7 @@ apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 resources:
   - https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.10.1/deploy/static/provider/do/deploy.yaml
+  - service.yaml
 patchesStrategicMerge:
   - |-
     apiVersion: v1
@@ -26,6 +27,23 @@ patchesStrategicMerge:
       replicas: 3
       template:
         spec:
+          containers:
+            - name: controller
+              args:
+                - /nginx-ingress-controller
+                - --publish-service=$(POD_NAMESPACE)/ingress-nginx-controller
+                - --election-id=ingress-nginx-leader
+                - --controller-class=k8s.io/ingress-nginx
+                - --ingress-class=nginx
+                - --configmap=$(POD_NAMESPACE)/ingress-nginx-controller
+                - --validating-webhook=:8443
+                - --validating-webhook-certificate=/usr/local/certificates/cert
+                - --validating-webhook-key=/usr/local/certificates/key
+                - --enable-metrics=true
+              ports:
+                - name: metrics
+                  containerPort: 10254
+                  protocol: TCP
           affinity:
             podAntiAffinity:
               requiredDuringSchedulingIgnoredDuringExecution:

platform/ingress-nginx/service.yaml

@@ -0,0 +1,20 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: ingress-nginx-controller-metrics
+  namespace: ingress-nginx
+  labels:
+    app.kubernetes.io/name: ingress-nginx
+    app.kubernetes.io/instance: ingress-nginx
+    app.kubernetes.io/component: controller
+spec:
+  type: ClusterIP
+  ports:
+    - name: metrics
+      port: 10254
+      targetPort: 10254
+      protocol: TCP
+  selector:
+    app.kubernetes.io/name: ingress-nginx
+    app.kubernetes.io/instance: ingress-nginx
+    app.kubernetes.io/component: controller