Add deployment docs for AWS NLB (#1785)

deploy/README.md

@@ -108,6 +108,11 @@ nginx-ingress-controller-fdcdcd6dd-vvpgs   1/1       Running   0          11s
 ### AWS
 
 In AWS we use an Elastic Load Balancer (ELB) to expose the NGINX Ingress controller behind a Service of `Type=LoadBalancer`.
+Since Kubernetes v1.9.0 it is possible to use a classic load balancer (ELB) or network load balancer (NLB)
+Please check the [elastic load balancing AWS details page](https://aws.amazon.com/es/elasticloadbalancing/details/)
+
+#### Elastic Load Balancer - ELB
+
 This setup requires to choose in which layer (L4 or L7) we want to configure the ELB:
 
 - [Layer 4](https://en.wikipedia.org/wiki/OSI_model#Layer_4:_Transport_Layer): use TCP as the listener protocol for ports 80 and 443.
@@ -153,6 +158,29 @@ If not run:
 kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/provider/patch-service-without-rbac.yaml
 ```
 
+#### Network Load Balancer (NLB)
+
+This type of load balancer is supported since v1.9.0 as an ALPHA feature.
+
+```console
+kubectl patch deployment -n ingress-nginx nginx-ingress-controller --type='json' \
+  --patch="$(curl https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/patch-deployment.yaml)"
+
+kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/provider/aws/service-nlb.yaml
+```
+
+If the ingress controller uses RBAC run:
+
+```console
+kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/provider/patch-service-with-rbac.yaml
+```
+
+If not run:
+
+```console
+kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/provider/patch-service-without-rbac.yaml
+```
+
 ### GCE - GKE
 
 Patch the nginx ingress controller deployment to add the flag `--publish-service`

deploy/provider/aws/service-nlb.yaml

@@ -0,0 +1,23 @@
+kind: Service
+apiVersion: v1
+metadata:
+  name: ingress-nginx
+  namespace: ingress-nginx
+  labels:
+    app: ingress-nginx
+  annotations:
+    # by default the type is elb (classic load balancer).
+    service.beta.kubernetes.io/aws-load-balancer-type: nlb
+spec:
+  # this setting is t make sure the source IP address is preserved.
+  externalTrafficPolicy: Local
+  type: LoadBalancer
+  selector:
+    app: ingress-nginx
+  ports:
+  - name: http
+    port: 80
+    targetPort: http
+  - name: https
+    port: 443
+    targetPort: https