Add metrics port

Author: ghokun

manifests/device-plugin.yml

@@ -55,6 +55,9 @@ spec:
             allowPrivilegeEscalation: false
             capabilities:
               drop: ["ALL"]
+          ports:
+            - containerPort: 8080
+              name: metrics
           volumeMounts:
             - name: device-plugin
               mountPath: /var/lib/kubelet/device-plugins