Update flannel vxlan port to 4789 (#982)

* Update flannel vxlan port to 4789

The IANA port assignment for flannel is 4789, so
change from the Linux default of 8472 so that it
works nicely with tools like Wireshark.

https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=4789

* fix indentation and add comma

Author: rphillips

Documentation/network-requirements.md

@@ -8,8 +8,8 @@ The information below describes a minimum set of port allocations used by Kubern
 
 | Protocol | Port Range | Source                                    | Purpose                |
 -----------|------------|-------------------------------------------|------------------------|
-| TCP      | 6443       | Worker Nodes, API Requests, and End-Users | Kubernetes API server. |
-| UDP      | 8472       | Master & Worker Nodes                     | flannel overlay network - *vxlan backend* |
+| TCP      | 443        | Worker Nodes, API Requests, and End-Users | Kubernetes API server. |
+| UDP      | 4789       | Master & Worker Nodes                     | flannel overlay network - *vxlan backend* |
 
 ### etcd node(s) ingress
 
@@ -22,7 +22,7 @@ The information below describes a minimum set of port allocations used by Kubern
 | Protocol | Port Range  | Source                         | Purpose                                                                |
 -----------|-------------|--------------------------------|------------------------------------------------------------------------|
 | TCP      | 4194        | Master & Worker Nodes          | The port of the localhost cAdvisor endpoint |
-| UDP      | 8472        | Master & Worker Nodes          | flannel overlay network - *vxlan backend* |
+| UDP      | 4789        | Master & Worker Nodes          | flannel overlay network - *vxlan backend* |
 | TCP      | 10250       | Master Nodes                   | Worker node Kubelet API for exec and logs.                                  |
 | TCP      | 10255       | Master & Worker Nodes          | Worker node read-only Kubelet API (Heapster).                                  |
 | TCP      | 30000-32767 | External Application Consumers | Default port range for [external service][https://kubernetes.io/docs/concepts/services-networking/service] ports. Typically, these ports would need to be exposed to external load-balancers, or other external consumers of the application itself. |

pkg/asset/internal/templates.go

@@ -1011,7 +1011,8 @@ data:
     {
       "Network": "{{ .PodCIDR }}",
       "Backend": {
-        "Type": "vxlan"
+        "Type": "vxlan",
+        "Port": 4789
       }
     }
 `)