1. Dockerfile :

    * dockerfile 是一个包含创建所有命令的文本文件，使用docker build 根据dockerfile命令创建新的镜像
    * FROM tomcat  # 参考的基础镜像
    * MAINTAINER  #标识镜像创建者
    * 执行命令
          * RUN rm -f  /usr/local/tomcat/webapps/ROOT/index.jsp
          * RUN echo "welcome to tomcat!" >/usr/local/tomcat/webapps/ROOT/index.html
   

2. 构建镜像：跟进dockerfile 文件自动构建镜像

    * docker build -f Dockerfile当前路径 -t xianwei/tomcat:v2 .
    *exp: $ docker build -f dockerfile -t xianwei/tomcat:v2 .
    * [python@localhost ~]$ sudo docker build -f /dockerfile -t xianwei/tomcat:v2 .
         Sending build context to Docker daemon  196.6MB
         Step 1/4 : FROM tomcat
           ---> ef802ca71927
           Step 2/4 : MAINTAINER Eric
            ---> Running in 328055e1575c
           Removing intermediate container 328055e1575c
           ---> 35ebde183840
           Step 3/4 : RUN rm -f /usr/local/tomcat/webapps/ROOT/index.jsp
           ---> Running in 29be0a87fdbc
           Removing intermediate container 29be0a87fdbc
            ---> 567478df2a70
           Step 4/4 : RUN echo "welcome to tomcat!"        >/usr/local/tomcat/webapps/ROOT/index.html
            ---> Running in c55851466c73
            Removing intermediate container c55851466c73
             ---> 04819a1dbce5
   		   Successfully built 04819a1dbce5
   		   Successfully tagged xianwei/tomcat:v2
   

3.使用新镜像运行容器

        $ sudo docker run --name v2 -p 9999:8080 -d 04819a1dbce5				

4.查看容器元信息 # $ sudo docker inspect tomcat:v3