Add instructions how to deploy to kubeadm

examples/deployment/nginx/kubeadm/README.md

@@ -0,0 +1,38 @@
+# Deploying the Nginx Ingress controller on kubeadm clusters
+
+This example aims to demonstrate the deployment of an nginx ingress controller with kubeadm, 
+and is nearly the same as the the example above, but here the Ingress Controller is using 
+`hostNetwork: true` until the CNI kubelet networking plugin is compatible with `hostPort`
+(see issue: [kubernetes/kubernetes#31307](https://github.com/kubernetes/kubernetes/issues/31307))
+
+## Default Backend
+
+The default backend is a Service capable of handling all url paths and hosts the
+nginx controller doesn't understand. This most basic implementation just returns
+a 404 page.
+
+## Controller
+
+The Nginx Ingress Controller uses nginx (surprisingly!) to loadbalance requests that are coming to
+ports 80 and 443 to Services in the cluster.
+
+```console
+$ kubectl apply -f https://rawgit.com/kubernetes/ingress/master/examples/deployment/nginx/kubeadm/nginx-ingress-controller.yaml
+deployment "default-http-backend" created
+service "default-http-backend" created
+deployment "nginx-ingress-controller" created
+```
+
+Note the default settings of this controller:
+* serves a `/healthz` url on port 10254, as both a liveness and readiness probe
+* automatically deploys the `gcr.io/google_containers/defaultbackend:1.0` image for serving 404 requests.
+
+At its current state, it only supports running on `amd64` nodes.
+
+## Running on a cloud provider
+
+If you're running this ingress controller on a cloudprovider, you should assume
+the provider also has a native Ingress controller and set the annotation
+`kubernetes.io/ingress.class: nginx` in all Ingresses meant for this controller.
+You might also need to open a firewall-rule for ports 80/443 of the nodes the
+controller is running on.