Fix docker.md with data volume container

Docker.md

@@ -1,16 +1,32 @@
-# docker run
+## Running Minio in Docker.
 
-To run docker image:
+### Installing Docker.
-```docker run -p 9000:9000 minio/minio:latest```
 
-This will start minio server in the docker container, the data however is not persistent.
+```bash
-If you need persistent storage you can use the command:
+sudo apt-get install Docker.io
+```
 
-```docker run -p 9000:9000 -v ${HOME}/.minio:/.minio -v ${HOME}/export:/export minio:latest```
+### Generating `minio configs` for the first time.
 
-Here the data uploaded to the minio server will be persisted to ${HOME}/export directory.
+```bash
+docker run -p 9000:9000 minio/minio:latest
+```
 
-# docker build
+### Persist `minio configs`.
 
-To build the docker image:
+```bash
-```make dockerimage TAG="<tag>"```
+docker commit <running_minio_container_id> minio/my-minio
+docker stop <running_minio_container_id>
+```
+
+### Create a data volume container.
+
+```bash
+docker create -v /export --name minio-export minio/my-minio /bin/true
+```
+
+You can then use the `--volumes-from` flag to mount the `/export` volume in another container.
+
+```bash
+docker run -p 9000:9000 --volumes-from minio-export --name minio1 minio/my-minio
+```