Update readme (#21)

Author: foxish

README.md

@@ -6,9 +6,45 @@ title: Spark on Kubernetes Integration Tests
 # Running the Kubernetes Integration Tests
 
 Note that the integration test framework is currently being heavily revised and
-is subject to change.
+is subject to change. Note that currently the integration tests only run with Java 8.
 
-Note that currently the integration tests only run with Java 8.
+As shorthand to run the tests against any given cluster, you can use the `e2e/runner.sh` script.
+The script assumes that you have a functioning Kubernetes cluster (1.6+) with kubectl
+configured to access it. The master URL of the currently configured cluster on your
+machine can be discovered as follows:
+
+```
+$ kubectl cluster-info
+
+Kubernetes master is running at https://xyz
+```
+
+If you want to use a local [minikube](https://github.com/kubernetes/minikube) cluster,
+the minimum tested version is 0.23.0, with the kube-dns addon enabled
+and the recommended configuration is 3 CPUs and 4G of memory. There is also a wrapper
+script for running on minikube, `e2e/e2e-minikube.sh` for testing the apache/spark repo
+in specific.
+
+```
+$ minikube start --memory 4000 --cpus 3
+```
+
+If you're using a non-local cluster, you must provide an image repository
+which you have write access to, using the `-i` option, in order to store docker images
+generated during the test.
+
+Example usages of the script:
+
+```
+$ ./e2e/runner.sh -m https://xyz -i docker.io/foxish -d cloud
+$ ./e2e/runner.sh -m https://xyz -i test -d minikube
+$ ./e2e/runner.sh -m https://xyz -i test -r https://github.com/my-spark/spark -d minikube
+
+```
+
+# Detailed Documentation
+
+## Running the tests using maven
 
 Running the integration tests requires a Spark distribution package tarball that
 contains Spark jars, submission clients, etc. You can download a tarball from
@@ -40,7 +76,7 @@ $ mvn clean integration-test  \
     -Dspark-distro-tgz=spark/spark-2.3.0-SNAPSHOT-bin.tgz
 ```
 
-# Running against an arbitrary cluster
+## Running against an arbitrary cluster
 
 In order to run against any cluster, use the following:
 ```sh
@@ -49,7 +85,7 @@ $ mvn clean integration-test  \
     -DextraScalaTestArgs="-Dspark.kubernetes.test.master=k8s://https://<master> -Dspark.docker.test.driverImage=<driver-image> -Dspark.docker.test.executorImage=<executor-image>"
 ```
 
-# Preserve the Minikube VM
+## Preserve the Minikube VM
 
 The integration tests make use of
 [Minikube](https://github.com/kubernetes/minikube), which fires up a virtual
@@ -64,7 +100,7 @@ $ mvn clean integration-test  \
     -DextraScalaTestArgs=-Dspark.docker.test.persistMinikube=true
 ```
 
-# Reuse the previous Docker images
+## Reuse the previous Docker images
 
 The integration tests build a number of Docker images, which takes some time.
 By default, the images are built every time the tests run.  You may want to skip