Merge pull request pires#7 from selvakn/master

Updating README with the rc env variables

Author: pires

README.md

@@ -13,3 +13,20 @@ Ready to use lean (213MB) Elasticsearch Docker image ready for using within a Ku
 ## Run
 
 See [pires/kubernetes-elasticsearch-cluster](https://github.com/pires/kubernetes-elasticsearch-cluster) for instructions on how to run, scale and use Elasticsearch on Kubernetes.
+
+## ENV variables
+(that can be used in replication controller)
+
+*Elasticsearch configuration variables*
+
+* [CLUSTER_NAME](https://www.elastic.co/guide/en/elasticsearch/reference/current/setup-configuration.html#cluster-name)
+* [NODE_MASTER](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-node.html#master-node)
+* [NODE_DATA](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-node.html#data-node)
+* [NETWORK_HOST](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-network.html#common-network-settings)
+* [HTTP_ENABLE](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-http.html#_settings_2)
+* [HTTP_CORS_ENABLE](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-http.html#_settings_2)
+
+*Kubernetes discovery plugin variables*
+
+* [DISCOVERY_SERVICE](https://github.com/fabric8io/elasticsearch-cloud-kubernetes#kubernetes-pod-discovery)
+* [NAMESPACE](https://github.com/fabric8io/elasticsearch-cloud-kubernetes#kubernetes-pod-discovery)