Merge pull request #110 from cherrylzhao/dev

Please make sure master-slave data sync on MySQL is running correctly. Otherwise this example will query empty data from slave.

## Using docker-compose to config startup environment

### before we use docker compose, please install docker first : https://docs.docker.com/compose/install/

### usage is as following :

1. access the docker folder (cd docker)

before we use docker compose, please install docker first : https://docs.docker.com/compose/install/

#### sharding-jdbc

1. access the docker folder (cd docker/sharding-jdbc/sharding)

2. launch the environment by docker compose (docker-compose up -d)

3. access mysql / etcd / zookeeper as you want

4. if there is conflict on port, just modify the mapper port in docker-compose.yml and then launch docker compose again(docker-compose up -d)

5. if you want to stop these environment, use command docker-compose stop

5. if you want to stop these environment, use command docker-compose down

#### sharding-proxy

1. access the docker folder (cd docker/sharding-proxy/sharding)

2. launch the environment by docker compose (docker-compose up -d)

3. access proxy by `mysql -h127.0.0.1 -P13308 -proot -uroot`

4. if there is conflict on port, just modify the mapper port in docker-compose.yml and then launch docker compose again(docker-compose up -d)

5. if you want to stop these environment, use command docker-compose down

to clean the docker container , you could use docker rm `docker ps -a -q` (be careful)