Docker如何使用link建立容器之间的连接

FROM centos:centos6
MAINTAINER David "xx@xx.com"
RUN yum install -y mysql-server mysql
RUN /etc/init.d/mysqld start
RUN mysql -e "grant all privileges on *.* to 'root'@'%' identified by '1234';"
RUN mysql -e "grant all privileges on *.* to 'root'@'localhost' identified by '1234';"
EXPOSE 3306
CMD ["/usr/bin/mysqld"]

FROM centos:centos6
MAINTAINER David "xx@xx.com"
RUN yum install -y mysql

David@MacBook-Pro-3 ~$ docker build -t hzc/mysql_server  /path/mysql_server/Dockerfile

David@MacBook-Pro-3 ~$ docker build -t hzc/mysql_client  /path/mysql_client/Dockerfile

David@MacBook-Pro-3 ~$ docker image|grep hzc
hzc/mysql_client     latest       62cfe52e02bf    2 days ago     289 MB
hzc/mysql_server     latest       83c64aba0805    2 days ago     377.9 MB

David@MacBook-Pro-3 ~$ docker run -d -P --name=mysql_server hzc/mysql_server
David@MacBook-Pro-3 ~$ b5e097fe510d8f258dd82c48a2f6aa4c279e227c4472e42d3e9956ac419ae73c

David@MacBook-Pro-3 ~$ docker run --name=mysql_client1 --link=mysql_server:db -i -t hzc/mysql_client mysql -h db -uroot -p1234

Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.1.73 Source distribution

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

David@MacBook-Pro-3 ~$ docker ps
CONTAINER ID    IMAGE        COMMAND         CREATED       STATUS       PORTS           NAMES
213285ec2663    hzc/mysql_client  "mysql -h db -uroot -"  2 minutes ago    Up 2 minutes                 mysql_client1
b5e097fe510d    hzc/mysql_server  "/usr/bin/mysqld_safe"  4 minutes ago    Up 4 minutes    0.0.0.0:32768->3306/tcp  mysql_server

David@MacBook-Pro-3 ~$ docker exec -it 213285ec2663 bash
[root@213285ec2663 /]# env
HOSTNAME=213285ec2663
DB_NAME=/mysql_client1/db
TERM=xterm
DB_PORT=tcp://172.17.0.2:3306
DB_PORT_3306_TCP_PORT=3306
....
DB_PORT_3306_TCP_PROTO=tcp
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
PWD=/
DB_PORT_3306_TCP_ADDR=172.17.0.2
SHLVL=1
HOME=/root
DB_PORT_3306_TCP=tcp://172.17.0.2:3306
no_proxy=*.local, 169.254/16
DB_ENV_no_proxy=*.local, 169.254/16
LESSOPEN=||/usr/bin/lesspipe.sh %s
G_BROKEN_FILENAMES=1
_=/usr/bin/env

[root@213285ec2663 /]# cat /etc/hosts
127.0.0.1  localhost
....
172.17.0.2  db b5e097fe510d mysql_server
172.17.0.3  213285ec2663