Update spark README with container location and DNS req.

spark/README.md

@@ -37,23 +37,25 @@ Following this example, you will create a functional [Apache
 Spark](http://spark.apache.org/) cluster using Kubernetes and
 [Docker](http://docker.io).
 
-You will setup a Spark master service and a set of
-Spark workers using Spark's [standalone mode](http://spark.apache.org/docs/latest/spark-standalone.html).
+You will setup a Spark master service and a set of Spark workers using Spark's [standalone mode](http://spark.apache.org/docs/latest/spark-standalone.html).
 
 For the impatient expert, jump straight to the [tl;dr](#tldr)
 section.
 
 ### Sources
 
-The Docker images are heavily based on https://github.com/mattf/docker-spark
+The Docker images are heavily based on https://github.com/mattf/docker-spark.
+And are curated in https://github.com/kubernetes/application-images/tree/master/spark
 
 ## Step Zero: Prerequisites
 
-This example assumes you have a Kubernetes cluster installed and
-running, and that you have installed the ```kubectl``` command line
-tool somewhere in your path. Please see the [getting
-started](../../docs/getting-started-guides/) for installation
-instructions for your platform.
+This example assumes
+
+- You have a Kubernetes cluster installed and running.
+- That you have installed the ```kubectl``` command line tool somewhere in your path.
+- That a spark-master service which spins up will be automatically discoverable by your kube DNS impl, as 'spark-master'
+
+For details, you can look at the Dockerfiles in the Sources section.
 
 ## Step One: Start your Master service
 
@@ -190,7 +192,7 @@ Zeppelin needs the Master service to be running.
 ### Check to see if Zeppelin is running
 
 ```console
-$ kubectl get pods -lcomponent=zeppelin
+$ kubectl get pods -l component=zeppelin
 NAME                        READY     STATUS    RESTARTS   AGE
 zeppelin-controller-ja09s   1/1       Running   0          53s
 ```