driver.rkt: add documentation about Networking

website/source/docs/drivers/rkt.html.md

@@ -73,6 +73,19 @@ The `rkt` driver supports the following configuration in the job spec:
 * `dns_search_domains` - (Optional) A list of DNS search domains to be used in
    the containers.
 
+* `net` - (Optional) A list of networks to be used by the containers
+
+* `port_map` - (Optional) A key/value map of port to be used by the container.
+   port name in the image manifest file needs to be specified for the value. For example:
+
+   ```
+    port_map {
+            app = "8080-tcp"
+    }
+   ```
+
+   See below for more details.
+
 * `debug` - (Optional) Enable rkt command debug option.
 
 * `volumes` - (Optional) A list of `host_path:container_path` strings to bind
@@ -84,6 +97,50 @@ The `rkt` driver supports the following configuration in the job spec:
     }
     ```
 
+## Networking
+
+The `rkt` can specify `--net` and `--port` for the rkt client. Hence, there are two ways to use host ports by
+using `--net=host` or `--port=PORT` with your network.
+
+Example:
+
+```
+		task "etcd" {
+			# Use Docker to run the task.
+			driver = "rkt"
+
+			config {
+				image = "docker://my_image"
+				net = ["containers"]
+                                port_map {
+                                        app = "8080-tcp"
+                                }
+			}
+
+			service {
+                                port = "app"
+			}
+
+			resources {
+                                network {
+                                        mbits = 10
+                                        port "app" {
+					    static = 12345
+                                        }
+                                }
+			}
+		}
+
+```
+
+### Allocating Ports
+
+You can allocate ports to your task using the port syntax described on the
+[networking page](/docs/jobspec/networking.html).
+
+When you use port allocation, the image manifest needs to declare public ports and host has configured network.
+For more information, please refer to [rkt Networking](https://coreos.com/rkt/docs/latest/networking/overview.html).
+
 ## Client Requirements
 
 The `rkt` driver requires rkt to be installed and in your system's `$PATH`.