Docker学习六：镜像

• 四 Docker镜像详解
• • 4.1什么是镜像
  • 4.2 Docker镜像加载原理
  • 4.3提交自己的镜像

镜像是一种轻量级、可执行的独立软件包，用来打包软件运行环境和基于运行环境开发的软件，它包含运行某个软件所需要的所有内容，包括代码，运行时（一个程序在运行或者在被执行的依赖）、库，环境变量和配置文件。

Docker的镜像实际上由一层一层的文件系统组成，这种层级的文件系统是UnionFS联合文件系统。

docker ps 查看容器

使用docker commit 命令提交容器成为一个新的版本

docker commit -m=“提交的描述信息”  -a="作者" 容器id 目标镜像名:[TAG] 

#1.复制文件夹
[root@iZwz99sm8v95sckz8bd2c4Z ~]# docker run -it tomcat /bin/bash
root@2a3bf3eaa2e4:/usr/local/tomcat# cd webapps
root@2a3bf3eaa2e4:/usr/local/tomcat/webapps# ls
root@2a3bf3eaa2e4:/usr/local/tomcat/webapps# cd ../
root@2a3bf3eaa2e4:/usr/local/tomcat# cp -r webapps.dist/* webapps
root@2a3bf3eaa2e4:/usr/local/tomcat# cd webapps
root@2a3bf3eaa2e4:/usr/local/tomcat/webapps# ls
ROOT  docs  examples  host-manager  manager
[root@iZwz99sm8v95sckz8bd2c4Z ~]# docker ps
ConTAINER ID   IMAGE                 COMMAND        CREATED         STATUS         PORTS                    NAMES
2a3bf3eaa2e4   tomcat                "/bin/bash"    4 minutes ago   Up 4 minutes   8080/tcp                 competent_torvalds
7789d4505a00   portainer/portainer   "/portainer"   24 hours ago    Up 24 hours    0.0.0.0:8088->9000/tcp   quirky_sinoussi
[root@iZwz99sm8v95sckz8bd2c4Z ~]# docker exec -it 2a3bf3eaa2e4 /bin/bash
root@2a3bf3eaa2e4:/usr/local/tomcat# cd webapps
root@2a3bf3eaa2e4:/usr/local/tomcat/webapps# ls
ROOT  docs  examples  host-manager  manager
root@2a3bf3eaa2e4:/usr/local/tomcat/webapps# cd ../
root@2a3bf3eaa2e4:/usr/local/tomcat# read escape sequence
[root@iZwz99sm8v95sckz8bd2c4Z ~]# docker ps
ConTAINER ID   IMAGE                 COMMAND        CREATED         STATUS         PORTS                    NAMES
2a3bf3eaa2e4   tomcat                "/bin/bash"    8 minutes ago   Up 8 minutes   8080/tcp                 competent_torvalds
7789d4505a00   portainer/portainer   "/portainer"   24 hours ago    Up 24 hours    0.0.0.0:8088->9000/tcp   quirky_sinoussi
#2.提交镜像作为一个新的镜像

[root@iZwz99sm8v95sckz8bd2c4Z ~]# docker commit -m="add webapps" -a="Ethan" 2a3bf3eaa2e4 mytomcat:1.0
sha256:f189aac861de51087af5bc88a5f1de02d9574e7ee2d163c647dd7503a2d3982b
[root@iZwz99sm8v95sckz8bd2c4Z ~]# docker images
REPOSITORY            TAG       IMAGE ID       CREATED         SIZE
mytomcat              1.0       f189aac861de   7 seconds ago   653MB
mysql                 5.7       f07dfa83b528   6 days ago      448MB
tomcat                latest    feba8d001e3f   10 days ago     649MB
nginx                 latest    ae2feff98a0c   12 days ago     133MB
centos                latest    300e315adb2f   2 weeks ago     209MB
portainer/portainer   latest    62771b0b9b09   5 months ago    79.1MB
elasticsearch         7.6.2     f29a1ee41030   9 months ago    791MB

#3.运行容器

[root@iZwz99sm8v95sckz8bd2c4Z ~]# docker run -it mytomcat:1.0 /bin/bash
root@1645774d4605:/usr/local/tomcat# cd webapps
root@1645774d4605:/usr/local/tomcat/webapps# ls
ROOT  docs  examples  host-manager  manager
wz99sm8v95sckz8bd2c4Z ~]# docker images
REPOSITORY            TAG       IMAGE ID       CREATED         SIZE
mytomcat              1.0       f189aac861de   7 seconds ago   653MB
mysql                 5.7       f07dfa83b528   6 days ago      448MB
tomcat                latest    feba8d001e3f   10 days ago     649MB
nginx                 latest    ae2feff98a0c   12 days ago     133MB
centos                latest    300e315adb2f   2 weeks ago     209MB
portainer/portainer   latest    62771b0b9b09   5 months ago    79.1MB
elasticsearch         7.6.2     f29a1ee41030   9 months ago    791MB