docker(11)：dockerfile自动构建镜像
docker(11)：dockerfile自动构建镜像
https://www.cnblogs.com/luoahong/p/10273820.html
1 手动docker镜像的缺点
相对于手动制作的docker镜像，使用dockerfile构建的镜像有以下优点：
- dockerfile只有几kb，便于传输
- 使用dockerfile构建出来的镜像，在运行容器的时候，不用指定容器的初始命令
- 支持更多的自定义操作
2 dockerfile详解
2.1 dockerfile主要组成部分
FROM #指定基础镜像FROM centos RUN #在命令前面加上RUN即可 RUN yum install httpd -y CMD #容器启动时执行的命令CMD [“/bin/bash”]
2.2 dockerfile常用指令：
FROM #指定基础镜像FROM centos MAINTAINER #指定维护者信息，可以没有 RUN #在命令前面加上RUN即可 RUN yum install httpd -y ADD #COPY文件，会自动解压 WORKDIR #设置当前工作目录 VOLUME #设置卷，挂载主机目录 EXPOSE #指定对外的端口-P 随机端口 CMD #容器启动时执行的命令CMD [“/bin/bash”]
2.3 dockerfile其他指令
COPY 复制文件
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
3 基于centos7支持systemctl-ssh-nginx的镜像
3.1 dockerfile
centos7如果需要systemctl命令，很麻烦
[root@docker-136 centos_ssh_nginx]# pwd /opt/dockerfile/centos_ssh_nginx [root@docker-136 centos_ssh_nginx]# ls dockerfile [root@docker-136 centos_ssh_nginx]# cat dockerfile FROM centos ENV container docker RUN (cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == systemd-tmpfiles-setup.service ] || rm -f $i; done); \ rm -f /lib/systemd/system/multi-user.target.wants/*;\ rm -f /etc/systemd/system/*.wants/*;\ rm -f /lib/systemd/system/local-fs.target.wants/*; \ rm -f /lib/systemd/system/sockets.target.wants/*udev*; \ rm -f /lib/systemd/system/sockets.target.wants/*initctl*; \ rm -f /lib/systemd/system/basic.target.wants/*;\ rm -f /lib/systemd/system/anaconda.target.wants/*; CMD ['--privileged=true'] RUN curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo RUN sed -i 's#$releasever#7#g' /etc/yum.repos.d/CentOS-Base.repo RUN sed -i 's#$basearch#x86_64#g' /etc/yum.repos.d/CentOS-Base.repo RUN curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo RUN yum install net-tools -y RUN yum install openssh-server -y RUN yum install nginx -y RUN echo 123456|passwd --stdin root RUN echo -e "#!/bin/sh \nsystemctl enable nginx \nsystemctl enable sshd " > /a.sh RUN chmod +x /a.sh RUN sh /a.sh CMD ["/usr/sbin/init"]
3.2 构建镜像
docker build -t centos-ssh-nginx-dockerfile:v1 . …….. ---> 140fbf3f1540 Successfully built 140fbf3f1540 Successfully tagged centos-ssh-nginx-dockerfile:v1 [root@docker-136 centos_ssh_nginx]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE centos-ssh-nginx-dockerfile v1 140fbf3f1540 8 minutes ago 712MB centos-7-ssh-nginx v1 93af120d6d0b 19 hours ago 413MB centos7-ssh v1 1b4f8be39f52 20 hours ago 316MB nginx latest e445ab08b2be 2 weeks ago 126MB httpd latest ee39f68eb241 3 weeks ago 154MB centos latest 9f38484d220f 4 months ago 202MB hello-world latest fce289e99eb9 7 months ago 1.84kB httpd 2.2 e06c3dbbfe23 18 months ago 171MB [root@docker-136 centos_ssh_nginx]#
3.3 启动容器测试镜像
docker run --privileged=true --name ssh-nginx-1 -d -p 4080:80 -p 4022:22 centos-^Ch-nginx-dockerfile:v1 [root@docker-136 centos_ssh_nginx]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES a369fcc6ef7e centos-ssh-nginx-dockerfile:v1 "/usr/sbin/init" 6 minutes ago Up 6 minutes 0.0.0.0:4022->22/tcp, 0.0.0.0:4080->80/tcp ssh-nginx-1 [root@docker-136 centos_ssh_nginx]# docker exec -it ssh-nginx-1 /bin/bash [root@a369fcc6ef7e /]# netstat -lntp Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 44/nginx: master pr tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 42/sshd tcp6 0 0 :::80 :::* LISTEN 44/nginx: master pr tcp6 0 0 :::22 :::* LISTEN 42/sshd [root@a369fcc6ef7e /]# systemctl list-dependencies|grep -E 'nginx|sshd' ● ├─nginx.service ● ├─sshd.service
