Base镜像（scratch）
Docker Hub中99%的镜像是通过在base镜像中安装和配置需要的软件构建出来的。也就是说base镜像是所有其他镜像的鼻祖。
hub默认centos镜像是什么情况
[root@t-docker chenzx]# docker run -it centos [root@ef7873879474 /]# vim a.txt ##默认ceonts不支持vim命令 bash: vim: command not found [root@ef7873879474 /]# ifconfig ##默认centos不支持ifconfig命令 bash: ifconfig: command not found
自定义镜像mycentos
1、编写Dokcerfile文件
[root@t-docker mycentos]# cat Dockerfile FROM centos MAINTAINER chenzx [email protected] ENV MYPATH /usr/local WORKDIR $MYPATH RUN yum -y install vim RUN yum -y install net-tools EXPOSE 80 CMD echo $MYPATH CMD echo "success-----ok" CMD /bin/bash
2、构建
语法：docker build -t 新镜像名字：TAG .
[root@t-docker mycentos]# docker build -f ./Dockerfile -t mycentos:1.3 . Sending build context to Docker daemon 2.048kB Step 1/10 : FROM centos ---> 5182e96772bf Step 2/10 : MAINTAINER chenzx [email protected] ---> Running in bf692c9a8f30 Removing intermediate container bf692c9a8f30 ---> be7c6d72dcf6 Step 3/10 : ENV MYPATH /usr/local ---> Running in bfbe973063c4 Removing intermediate container bfbe973063c4 ---> b6117be61d21 Step 4/10 : WORKDIR $MYPATH ---> Running in dc207977e37e Removing intermediate container dc207977e37e ---> a299de1b142d Step 5/10 : RUN yum -y install vim ---> Running in 7b18a2ea02ba Loaded plugins: fastestmirror, ovl Determining fastest mirrors * base: mirror.bit.edu.cn * extras: mirror.bit.edu.cn * updates: mirror.bit.edu.cn Resolving Dependencies --> Running transaction check ---> Package vim-enhanced.x86_64 2:7.4.160-4.el7 will be installed --> Processing Dependency: vim-common = 2:7.4.160-4.el7 for package: 2:vim-enhanced-7.4.160-4.el7.x86_64 --> Processing Dependency: which for package: 2:vim-enhanced-7.4.160-4.el7.x86_64 --> Processing Dependency: perl(:MODULE_COMPAT_5.16.3) for package: 2:vim-enhanced-7.4.160-4.el7.x86_64 --> Processing Dependency: libperl.so()(64bit) for package: 2:vim-enhanced-7.4.160-4.el7.x86_64 ---> 41b54eafc062 Step 6/10 : RUN yum -y install net-tools ---> Running in 4fe95a3f928d Loaded plugins: fastestmirror, ovl Loading mirror speeds from cached hostfile * base: mirror.bit.edu.cn * extras: mirror.bit.edu.cn * updates: mirror.bit.edu.cn Resolving Dependencies --> Running transaction check Step 7/10 : EXPOSE 80 ---> Running in b49331f041a0 Removing intermediate container b49331f041a0 ---> 255ce503616b Step 8/10 : CMD echo $MYPATH ---> Running in 0c8a45aa210f Removing intermediate container 0c8a45aa210f ---> b70d750b50c6 Step 9/10 : CMD echo "success-----ok" ---> Running in 0f82aaeab3af Removing intermediate container 0f82aaeab3af ---> 41680031171e Step 10/10 : CMD /bin/bash ---> Running in 5694bd9a1dab Removing intermediate container 5694bd9a1dab ---> 0c868c56748b Successfully built 0c868c56748b Successfully tagged mycentos:1.3 [root@t-docker mycentos]#
3、运行
[root@t-docker mycentos]# docker run -it mycentos:1.3
[root@28ab180a72d7 local]# pwd ##落脚点是/usr/local
/usr/local
[root@28ab180a72d7 local]# vim a.txt ##vim命令也有了
[root@28ab180a72d7 local]# ifconfig ##ifconfig命令有了
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.17.0.2 netmask 255.255.0.0 broadcast 172.17.255.255
ether 02:42:ac:11:00:02 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
loop txqueuelen 1000 (Local Loopback)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
[root@28ab180a72d7 local]#
4、列出镜像的变更历史
功能：从底下往上看，可以看出制作mycentos镜像的历史过程。
[root@t-docker mycentos]# docker images mycentos REPOSITORY TAG IMAGE ID CREATED SIZE mycentos 1.3 0c868c56748b 12 minutes ago 442MB [root@t-docker mycentos]# docker history 0c868c56748b IMAGE CREATED CREATED BY SIZE COMMENT 0c868c56748b 12 minutes ago /bin/sh -c #(nop) CMD ["/bin/sh" "-c" "/bin… 0B 41680031171e 12 minutes ago /bin/sh -c #(nop) CMD ["/bin/sh" "-c" "echo… 0B b70d750b50c6 12 minutes ago /bin/sh -c #(nop) CMD ["/bin/sh" "-c" "echo… 0B 255ce503616b 12 minutes ago /bin/sh -c #(nop) EXPOSE 80 0B 1cb7e8747969 12 minutes ago /bin/sh -c yum -y install net-tools 93.7MB 41b54eafc062 12 minutes ago /bin/sh -c yum -y install vim 149MB a299de1b142d 13 minutes ago /bin/sh -c #(nop) WORKDIR /usr/local 0B b6117be61d21 13 minutes ago /bin/sh -c #(nop) ENV MYPATH=/usr/local 0B be7c6d72dcf6 13 minutes ago /bin/sh -c #(nop) MAINTAINER chenzx chenzx@… 0B 5182e96772bf 3 weeks ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B <missing> 3 weeks ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B <missing> 3 weeks ago /bin/sh -c #(nop) ADD file:6340c690b08865d7e… 200MB