Create OAP README.md

6/6.1/oap/README.md

+# Apache SkyWalking OAP Server Docker Files
+
+<img src="http://skywalking.apache.org/assets/logo.svg" alt="Sky Walking logo" height="90px" align="right" />
+
+**SkyWalking**: an APM(application performance monitor) system, especially designed for 
+microservices, cloud native and container-based (Docker, Kubernetes, Mesos) architectures.
+
+# How to use this image
+
+## Start a `standlone` container with `H2` storage
+
+```
+$ docker run --name oap --restart always -d apache/skywalking-oap-server:6.1.0
+```
+
+## Start a `standlone` container with `elasticsearch` storage whose address is `elasticsearch:9200`
+
+```
+$ docker run --name oap --restart always -d -e SW_STORAGE=elasticsearch -e SW_STORAGE_ES_CLUSTER_NODES=elasticsearch:9200 apache/skywalking-oap-server:6.1.0
+```
+
+# Configuration
+
+We could setup enviroment variables to configure this image. Most of them is defined in [setup backends](), but Apache SkyWalking Docker Image adds extra enviroment variables to help user to compose it propertly.
+
+## SW_CLUSTER
+Default value is `standalone`, avaliable values are:
+ - `standlone`
+ - `zookeeper`
+ - `kubernetes`
+ - con
+## SW_STORAGE
+## XXX_ENABLED
+
+# License
+[Apache 2.0 License.](/LICENSE)