Docker数据管理
Docker的数据卷是可以绕过文件系统的，而且数据卷是可以共享，可重用的
查看数据卷：
[root@docker ~]# docker inspect -f {{.Volumes}} volume-test1
map[/data:/var/lib/docker/volumes/9f36c1a9b7728974566268a2beebb0b917226952280c96107388469659bfcfe5/_data]
[root@docker ~]# cd /var/lib/docker/
[root@docker docker]# ls
containers devicemapper graph init linkgraph.db repositories-devicemapper tmp trust volumes
[root@docker docker]# cd volumes/
[root@docker volumes]# ls -lrt
total 8
drwxr-xr-x 3 root root 4096 Feb 24 09:29 63ccf5d524567c835c6d542cfc74d1a28d28fdf48a0bca0c517cb8dedf46b632
drwxr-xr-x 3 root root 4096 Feb 24 09:30 9f36c1a9b7728974566268a2beebb0b917226952280c96107388469659bfcfe5
[root@docker volumes]# cd 9f36c1a9b7728974566268a2beebb0b917226952280c96107388469659bfcfe5/
[root@docker 9f36c1a9b7728974566268a2beebb0b917226952280c96107388469659bfcfe5]#
[root@docker ~]# docker run -it --name volume-test1 -h nginx -v /data centos
[root@nginx /]# ls /data
测试：
1、系统随机生成的目录，进行挂载
容器的宿主机： [root@docker 9f36c1a9b7728974566268a2beebb0b917226952280c96107388469659bfcfe5]# ls _data [root@docker 9f36c1a9b7728974566268a2beebb0b917226952280c96107388469659bfcfe5]# cd _data/ [root@docker _data]# ls passwd [root@docker _data]# dd if=/dev/zero of=test.iso bs=1M count=10 10+0 records in 10+0 records out 10485760 bytes (10 MB) copied, 0.00956288 s, 1.1 GB/s [root@docker _data]# ls passwd test.iso 容器内： [root@nginx /]# cd /data/ [root@nginx data]# ls [root@nginx data]# cp /etc/passwd . [root@nginx data]# ls passwd [root@nginx data]# ls passwd test.iso 说明：容器的宿主机的目录已共享给容器使用（删除容器后，原有的数据卷目录中的文件仍旧是存在的）
2、系统指定的目录，进行挂载
宿主机的操作： [root@docker ~]# mkdir -p /volume-test2-data [root@docker ~]# docker run -it -d --name volume-test2 -h centos7 --restart=always -v /volume-test2-data:/centos-data centos 29e9a41e563d514c8b9f14d14a0426af955651b28109c4851cfec40a186244d0 [root@docker ~]# docker ps -l CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 29e9a41e563d centos "/bin/bash" 7 seconds ago Up 5 seconds volume-test2 [root@docker ~]# cp -r /usr/share/doc/abrt-2.0.8/ /volume-test2-data/ [root@docker ~]# ls -l /volume-test2-data/ total 4 drwxr-xr-x 2 root root 4096 Feb 24 09:58 abrt-2.0.8 容器内的操作： [root@docker ~]# ./in.sh 29e9a41e563d [root@centos7 /]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/docker-8:3-8388750-29e9a41e563d514c8b9f14d14a0426af955651b28109c4851cfec40a186244d0 9.8G 230M 9.0G 3% / tmpfs 1.9G 0 1.9G 0% /dev shm 64M 0 64M 0% /dev/shm /dev/sda3 193G 11G 173G 6% /etc/hosts [root@centos7 /]# cd /centos-data/ [root@centos7 centos-data]# ls abrt-2.0.8 [root@centos7 centos-data]# cp /etc/passwd . [root@centos7 centos-data]# ls abrt-2.0.8 passwd [root@docker _data]# ls /volume-test2-data/ abrt-2.0.8 passwd
3、系统指定的目录，进行挂载（可挂载多个，并设置权限，默认为rw权限）
宿主机的操作： 先删除原有的容器 [root@docker ~]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 29e9a41e563d centos "/bin/bash" 11 minutes ago Up 11 minutes volume-test2 8884fc392971 nginx "nginx -g 'daemon of 13 hours ago Up 51 minutes 80/tcp, 443/tcp nginxdocker 14caa9ab03a9 dockerui/dockerui "/dockerui" 46 hours ago Up 51 minutes 0.0.0.0:9000->9000/tcp dockerui_qinwen e278cabec91e centos "/bin/bash" 47 hours ago Up 51 minutes centos_aways 删除正在允许的容器时，会有报错信息： [root@docker ~]# docker rm 29e9a41e563d -f Error response from daemon: Cannot destroy container 29e9a41e563d: Conflict, You cannot remove a running container. Stop the container before attempting removal or use -f Error response from daemon: no such id: -f Error: failed to remove containers: [29e9a41e563d -f] [root@docker ~]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 29e9a41e563d centos "/bin/bash" 11 minutes ago Up 11 minutes volume-test2 8884fc392971 nginx "nginx -g 'daemon of 13 hours ago Up 52 minutes 80/tcp, 443/tcp nginxdocker 14caa9ab03a9 dockerui/dockerui "/dockerui" 46 hours ago Up 52 minutes 0.0.0.0:9000->9000/tcp dockerui_qinwen e278cabec91e centos "/bin/bash" 47 hours ago Up 52 minutes centos_aways 先停止容器，然后再进行删除： [root@docker ~]# docker stop 29e9a41e563d 29e9a41e563d [root@docker ~]# docker rm 29e9a41e563d 29e9a41e563d [root@docker ~]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 8884fc392971 nginx "nginx -g 'daemon of 13 hours ago Up 52 minutes 80/tcp, 443/tcp nginxdocker 14caa9ab03a9 dockerui/dockerui "/dockerui" 46 hours ago Up 52 minutes 0.0.0.0:9000->9000/tcp dockerui_qinwen e278cabec91e centos "/bin/bash" 47 hours ago Up 52 minutes centos_aways 运行一个基于centos镜像的容器，容器名称为volume-test2，并设置容器中的主机名为centos7（仅对容器有效），挂载本地的/volume-test2-data以及/opt目录，并且指定/opt目录对容器是只读的 [root@docker ~]# docker run -it -d --name volume-test2 -h centos7 --restart=always -v /volume-test2-data:/centos-data -v /opt:/opt:ro centos 37652d4601948fe8421c0371278e9bee8c5cbb35f16c7bf755764d56ddafa304 [root@docker ~]# docker ps -l CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 37652d460194 centos "/bin/bash" 16 seconds ago Up 15 seconds volume-test2 [root@docker ~]# ./in.sh 37652d460194 容器内的操作： [root@centos7 /]# cd /opt/ [root@centos7 opt]# ls rh [root@centos7 opt]# ls opt.iso rh [root@centos7 opt]# touch 123.txt touch: cannot touch ‘123.txt’: Read-only file system --volume-from： 继承容器数据卷的操作： [root@docker ~]# docker run -it -d --restart=always --name volume-test04 --volumes-from volume-test2 centos 94ea720a2c418286d26068d126df35523742e2f910685863f876c3ba9c09638c [root@docker ~]# docker ps -l CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 94ea720a2c41 centos "/bin/bash" 6 seconds ago Up 4 seconds volume-test04 [root@docker ~]# ./in.sh 94ea720a2c41 [root@94ea720a2c41 /]# ls / anaconda-post.log centos-data etc lib lost+found mnt proc run srv tmp var bin dev home lib64 media opt root sbin sys usr [root@94ea720a2c41 /]# cd /opt/ [root@94ea720a2c41 opt]# ls opt.iso rh [root@94ea720a2c41 opt]# cd /centos-data/ [root@94ea720a2c41 centos-data]# ls abrt-2.0.8 passwd [root@94ea720a2c41 centos-data]# touch 12345.txt [root@94ea720a2c41 centos-data]# cd /opt [root@94ea720a2c41 opt]# ls opt.iso rh [root@94ea720a2c41 opt]# touch 111 touch: cannot touch ‘111’: Read-only file system 拥有volume-test2的容器的操作： [root@docker ~]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 94ea720a2c41 centos "/bin/bash" 45 seconds ago Up 43 seconds volume-test04 37652d460194 centos "/bin/bash" About an hour ago Up About an hour volume-test2 8884fc392971 nginx "nginx -g 'daemon of 14 hours ago Up About an hour 80/tcp, 443/tcp nginxdocker 14caa9ab03a9 dockerui/dockerui "/dockerui" 47 hours ago Up About an hour 0.0.0.0:9000->9000/tcp dockerui_qinwen e278cabec91e centos "/bin/bash" 2 days ago Up About an hour centos_aways [root@docker ~]# ./in.sh 37652d460194 [root@centos7 /]# ls anaconda-post.log centos-data etc lib lost+found mnt proc run srv tmp var bin dev home lib64 media opt root sbin sys usr [root@centos7 /]# cd /centos-data/ [root@centos7 centos-data]# ls abrt-2.0.8 passwd [root@centos7 centos-data]# ls 12345.txt abrt-2.0.8 passwd
进一步进行测试：
[root@docker ~]# docker run -it -d --restart=always --name volume-test04 --volumes-from volume-test2 centos 94ea720a2c418286d26068d126df35523742e2f910685863f876c3ba9c09638c 宿主机上的操作： [root@docker ~]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 94ea720a2c41 centos "/bin/bash" 14 minutes ago Up 14 minutes volume-test04 37652d460194 centos "/bin/bash" About an hour ago Up About an hour volume-test2 8884fc392971 nginx "nginx -g 'daemon of 14 hours ago Up 2 hours 80/tcp, 443/tcp nginxdocker 14caa9ab03a9 dockerui/dockerui "/dockerui" 47 hours ago Up 2 hours 0.0.0.0:9000->9000/tcp dockerui_qinwen e278cabec91e centos "/bin/bash" 2 days ago Up 2 hours [root@docker ~]# docker stop 37652d460194 37652d460194 [root@docker ~]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 94ea720a2c41 centos "/bin/bash" 14 minutes ago Up 14 minutes volume-test04 8884fc392971 nginx "nginx -g 'daemon of 14 hours ago Up 2 hours 80/tcp, 443/tcp nginxdocker 14caa9ab03a9 dockerui/dockerui "/dockerui" 47 hours ago Up 2 hours 0.0.0.0:9000->9000/tcp dockerui_qinwen e278cabec91e centos "/bin/bash" 2 days ago Up 2 hours centos_aways [root@docker _data]# cd /volume-test2-data [root@docker volume-test2-data]# ls 12345.txt abrt-2.0.8 passwd [root@docker volume-test2-data]# ls -lrt total 8 drwxr-xr-x 2 root root 4096 Feb 24 09:58 abrt-2.0.8 -rw-r--r-- 1 root root 692 Feb 24 10:01 passwd -rw-r--r-- 1 root root 0 Feb 24 11:16 12345.txt 容器内的操作： [root@94ea720a2c41 opt]# cd /centos-data/ [root@94ea720a2c41 centos-data]# ls -lrt total 8 drwxr-xr-x 2 root root 4096 Feb 24 01:58 abrt-2.0.8 -rw-r--r-- 1 root root 692 Feb 24 02:01 passwd -rw-r--r-- 1 root root 0 Feb 24 03:16 12345.txt [root@94ea720a2c41 centos-data]#
说明：
1、验证后可以发现，ro权限是正常的
2、这种映射在Dockerfile里面是没法使用的
3、这里我们不管volume-test2 所属的容器是否正在允许，在新主机中均能够继承