Docker的自动构建镜像

Dockerfile自动构建docker镜像
类似ansible剧本，大小几kb
手动做镜像：大小几百M+

dockerfile 支持自定义容器的初始命令

dockerfile主要组成部分：
 基础镜像信息       FROM  centos:6.9
 制作镜像操作指令   RUN yum install openssh-server -y
 容器启动时执行指令 CMD ["/bin/bash"]
dockerfile常用指令：
 FROM 这个镜像的妈妈是谁？（指定基础镜像）
 MAINTAINER 告诉别人，谁负责养它？（指定维护者信息，可以没有）
 LABLE      描述，标签
 
 RUN 你想让它干啥（在命令前面加上RUN即可）
 ADD 给它点创业资金（会自动解压tar）  制作docker基础的系统镜像
 WORKDIR 我是cd,今天刚化了妆（设置当前工作目录）
 VOLUME 给它一个存放行李的地方（设置卷，挂载主机目录）
 EXPOSE 它要打开的门是啥（指定对外的端口）(-P 随机端口)
 CMD 奔跑吧，兄弟！（指定容器启动后的要干的事情）（容易被替换）
 
dockerfile其他指令： 
 COPY 复制文件（不会解压）rootfs.tar.gz
 ENV  环境变量
 ENTRYPOINT  容器启动后执行的命令（无法被替换，启容器的时候指定的命令，会被当成参数）

参考其他的dockerfile
官方dockerfile或者时速云镜像广场

[root@localhost centos6.9_ssh_nginx]# pwd
/opt/dockerfile/centos6.9_ssh_nginx
[root@localhost centos6.9_ssh_nginx]# cat dockerfile
FROM centos:6.9

RUN curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
RUN curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
RUN yum -y install openssh-server nginx unzip
RUN service sshd start
RUN echo "123456"|passwd --stdin root
RUN rm -rf /usr/share/nginx/html/index.html
ADD xiaoniaofeifei.zip /usr/share/nginx/html/
RUN unzip /usr/share/nginx/html/xiaoniaofeifei.zip -d /usr/share/nginx/html/
ADD init.sh /init.sh
CMD ["/bin/bash","/init.sh"]

[root@localhost centos6.9_ssh_nginx]# cat init.sh
#!/bin/bash

service sshd restart
nginx -g 'daemon off;'

创建镜像
docker build --network=host -t centos6.9_nginx_ssh:v1 .

[root@localhost centos6.9_ssh_nginx]# docker images
REPOSITORY            TAG                 IMAGE ID            CREATED             SIZE
centos6.9_nginx_ssh   v1                  f01eeebf918a        9 minutes ago       431MB

优化上述dockerfile文件：

FROM centos:6.9

RUN curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
RUN curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
RUN yum -y install openssh-server nginx unzip
RUN service sshd start
RUN echo "123456"|passwd --stdin root
WORKDIR /usr/share/nginx/html      这里指的是之后所有命令都在这个路径下面执行
RUN rm -rf * 
ADD xiaoniaofeifei.zip .  这里最后是点不能忘记了，表示在当前目录
RUN unzip xiaoniaofeifei.zip

ADD init.sh /init.sh

CMD ["/bin/bash","/init.sh"]

　执行创建案之后的命令结果是：

[root@localhost centos6.9_ssh_nginx]# docker build --network=host -t centos6.9_nginx_ssh:v2 .
Sending build context to Docker daemon  94.72kB
Step 1/12 : FROM centos:6.9
 ---> adf829198a7f
Step 2/12 : RUN curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
 ---> Using cache
 ---> bcfa68985b33
Step 3/12 : RUN curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
 ---> Using cache
 ---> de91b8df3cdc
Step 4/12 : RUN yum -y install openssh-server nginx unzip
 ---> Using cache
 ---> 66bb9530d868
Step 5/12 : RUN service sshd start
 ---> Using cache
 ---> 5974df83e839
Step 6/12 : RUN echo "123456"|passwd --stdin root
 ---> Using cache
 ---> d8cbe019d081
Step 7/12 : WORKDIR /usr/share/nginx/html
 ---> Using cache
 ---> e4bf78b38489
Step 8/12 : RUN rm -rf *
 ---> Using cache
 ---> a7040fa17ab7
Step 9/12 : ADD xiaoniaofeifei.zip .
 ---> dcc79248a09f
Step 10/12 : RUN unzip xiaoniaofeifei.zip
 ---> Running in cbca6d5ca592
Archive:  xiaoniaofeifei.zip
  inflating: sound1.mp3
   creating: img/
  inflating: img/bg1.jpg
  inflating: img/bg2.jpg
  inflating: img/number1.png
  inflating: img/number2.png
  inflating: img/s1.png
  inflating: img/s2.png
  inflating: 21.js
  inflating: 2000.png
  inflating: icon.png
  inflating: index.html
Removing intermediate container cbca6d5ca592
 ---> f4a99a6a7128
Step 11/12 : ADD init.sh /init.sh
 ---> 455bf5fe6902
Step 12/12 : CMD ["/bin/bash","/init.sh"]
 ---> Running in e5caf5424a18
Removing intermediate container e5caf5424a18
 ---> 6307e23ee16d
Successfully built 6307e23ee16d
Successfully tagged centos6.9_nginx_ssh:v2
[root@localhost centos6.9_ssh_nginx]# docker images
REPOSITORY            TAG                 IMAGE ID            CREATED              SIZE
centos6.9_nginx_ssh   v2                  6307e23ee16d        About a minute ago   431MB
centos6.9_nginx_ssh   v1                  f01eeebf918a        16 minutes ago       431MB

[localhost centos6.9_ssh_nginx]# docker run -d -p 80:80 -p 2222:22 centos6.9_nginx_ssh:v2
277d3714590b9b9faaba1b682790c694bcc96f0868293d5505b69848f8d03421
[root@localhost centos6.9_ssh_nginx]# docker exec -it 277d37145 /bin/bash
[root@277d3714590b html]# pwd
/usr/share/nginx/html    从这里就可以看出目录由于设定了WORKDIR，所以钉死在了这个目录下面

在上面可以看出任然还有可以优化的地方，所以继续，使用ADD命令可以直接解压tar包

FROM centos:6.9

RUN curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
RUN curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
RUN yum -y install openssh-server nginx
RUN service sshd start
RUN echo "123456"|passwd --stdin root
WORKDIR /usr/share/nginx/html
RUN rm -rf *
ADD xiaoniaofeifei.tar.gz .        ADD可以直接解压tar包
ADD init.sh /init.sh

CMD ["/bin/bash","/init.sh"]



[root@localhost centos6.9_ssh_nginx]# docker build --network=host -t centos6.9_nginx_ssh:v3 .
Sending build context to Docker daemon  186.9kB
Step 1/11 : FROM centos:6.9
 ---> adf829198a7f
Step 2/11 : RUN curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
 ---> Using cache
 ---> bcfa68985b33
Step 3/11 : RUN curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
 ---> Using cache
 ---> de91b8df3cdc
Step 4/11 : RUN yum -y install openssh-server nginx
 ---> Using cache
 ---> 16a434cf89be
Step 5/11 : RUN service sshd start
 ---> Using cache
 ---> 60f03276a66c
Step 6/11 : RUN echo "123456"|passwd --stdin root
 ---> Using cache
 ---> b4dc176a311b
Step 7/11 : WORKDIR /usr/share/nginx/html
 ---> Using cache
 ---> 209c253860e4
Step 8/11 : RUN rm -rf *
 ---> Using cache
 ---> d8ca4eff7ee9
Step 9/11 : ADD xiaoniaofeifei.tar.gz .
 ---> 139914b243cb
Step 10/11 : ADD init.sh /init.sh
 ---> 482f2582dd02
Step 11/11 : CMD ["/bin/bash","/init.sh"]
 ---> Running in 66b1794dbe6e
Removing intermediate container 66b1794dbe6e
 ---> 92b1087df3f5
Successfully built 92b1087df3f5
Successfully tagged centos6.9_nginx_ssh:v3
[root@localhost centos6.9_ssh_nginx]# docker images
REPOSITORY            TAG                 IMAGE ID            CREATED              SIZE
centos6.9_nginx_ssh   v3                  92b1087df3f5        About a minute ago   431MB
centos6.9_nginx_ssh   v2                  6307e23ee16d        19 minutes ago       431MB
centos6.9_nginx_ssh   v1                  f01eeebf918a        35 minutes ago       431MB

　企业标准化EXPOSE

FROM centos:6.9

RUN curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
RUN curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
RUN yum -y install openssh-server nginx
RUN service sshd start
RUN echo "123456"|passwd --stdin root
WORKDIR /usr/share/nginx/html
RUN rm -rf *
ADD xiaoniaofeifei.tar.gz .
ADD init.sh /init.sh

EXPOSE 80/tcp 22/tcp
CMD ["/bin/bash","/init.sh"]

[root@localhost centos6.9_ssh_nginx]# docker build --network=host -t centos6.9_nginx_ssh:v4 .
Sending build context to Docker daemon  186.9kB
Step 1/12 : FROM centos:6.9
 ---> adf829198a7f
Step 2/12 : RUN curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
 ---> Using cache
 ---> bcfa68985b33
Step 3/12 : RUN curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
 ---> Using cache
 ---> de91b8df3cdc
Step 4/12 : RUN yum -y install openssh-server nginx
 ---> Using cache
 ---> 16a434cf89be
Step 5/12 : RUN service sshd start
 ---> Using cache
 ---> 60f03276a66c
Step 6/12 : RUN echo "123456"|passwd --stdin root
 ---> Using cache
 ---> b4dc176a311b
Step 7/12 : WORKDIR /usr/share/nginx/html
 ---> Using cache
 ---> 209c253860e4
Step 8/12 : RUN rm -rf *
 ---> Using cache
 ---> d8ca4eff7ee9
Step 9/12 : ADD xiaoniaofeifei.tar.gz .
 ---> Using cache
 ---> 139914b243cb
Step 10/12 : ADD init.sh /init.sh
 ---> Using cache
 ---> 482f2582dd02
Step 11/12 : EXPOSE 80/tcp 22/tcp
 ---> Running in 4a9a9c270afc
Removing intermediate container 4a9a9c270afc
 ---> b980eead4bdc
Step 12/12 : CMD ["/bin/bash","/init.sh"]
 ---> Running in fc73bab98352
Removing intermediate container fc73bab98352
 ---> ac9eca43049a
Successfully built ac9eca43049a
Successfully tagged centos6.9_nginx_ssh:v4

[root@localhost centos6.9_ssh_nginx]# docker images
REPOSITORY            TAG                 IMAGE ID            CREATED             SIZE
centos6.9_nginx_ssh   v4                  ac9eca43049a        45 seconds ago      431MB
centos6.9_nginx_ssh   v3                  92b1087df3f5        11 minutes ago      431MB
centos6.9_nginx_ssh   v2                  6307e23ee16d        29 minutes ago      431MB
centos6.9_nginx_ssh   v1                  f01eeebf918a        45 minutes ago      431MB
[root@localhost centos6.9_ssh_nginx]# docker run -d -P centos6.9_nginx_ssh:v4
697030125c669ee2e92ae09111833eec38cc00ba9ee367140de97ebcf95fbe00
[root@localhost centos6.9_ssh_nginx]# docker ps -al
CONTAINER ID        IMAGE                    COMMAND                CREATED             STATUS  PORTS                                          NAMES
697030125c66        centos6.9_nginx_ssh:v4   "/bin/bash /init.sh"   2 minutes ago       Up 2 minutes  0.0.0.0:32769->22/tcp, 0.0.0.0:32768->80/tcp   flamboyant_hoover

由上可知,加入了EXPOSE以后就能看到容器的端口出现随机映射的现象　

volume的意义：

[root@localhost centos6.9_ssh_nginx]# vim dockerfile

FROM centos:6.9

RUN curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
RUN curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
RUN yum -y install openssh-server nginx
RUN service sshd start
RUN echo "123456"|passwd --stdin root
WORKDIR /usr/share/nginx/html
RUN rm -rf *
ADD xiaoniaofeifei.tar.gz .
ADD init.sh /init.sh

EXPOSE 80/tcp 22/tcp
VOLUME /usr/share/nginx/html
CMD ["/bin/bash","/init.sh"]

[root@localhost centos6.9_ssh_nginx]# docker run -d -P centos6.9_nginx_ssh:v5 .

[root@localhost centos6.9_ssh_nginx]# docker volume ls
DRIVER              VOLUME NAME
local               b56d4c1f5042c2f7c2e8afd4e53f4f6c0ac9a1c09d12c5dd81ab40c783e09f07   产生一个随机的卷