docker学习（11）数据卷容器

我们现在想实现多个容器数据同步，比如多个Mysql数据同步，挂载了的容器被称为父容器。

现在我们先把容器1起一下，用我们上个文章创建的wang/centos

[root@wangstudy _data]# docker run -it --name docker1 wang/centos
[root@5cd8cba5139d /]# ls -l
total 56
lrwxrwxrwx   1 root root    7 May 11  2019 bin -> usr/bin
drwxr-xr-x   5 root root  360 Jun  3 10:43 dev
drwxr-xr-x   1 root root 4096 Jun  3 10:43 etc
drwxr-xr-x   2 root root 4096 May 11  2019 home
lrwxrwxrwx   1 root root    7 May 11  2019 lib -> usr/lib
lrwxrwxrwx   1 root root    9 May 11  2019 lib64 -> usr/lib64
drwx------   2 root root 4096 Jan 13 21:48 lost+found
drwxr-xr-x   2 root root 4096 May 11  2019 media
drwxr-xr-x   2 root root 4096 May 11  2019 mnt
drwxr-xr-x   2 root root 4096 May 11  2019 opt
dr-xr-xr-x 118 root root    0 Jun  3 10:43 proc
dr-xr-x---   2 root root 4096 Jan 13 21:49 root
drwxr-xr-x  11 root root 4096 Jan 13 21:49 run
lrwxrwxrwx   1 root root    8 May 11  2019 sbin -> usr/sbin
drwxr-xr-x   2 root root 4096 May 11  2019 srv
dr-xr-xr-x  13 root root    0 May 30 08:43 sys
drwxrwxrwt   7 root root 4096 Jan 13 21:49 tmp
drwxr-xr-x  12 root root 4096 Jan 13 21:49 usr
drwxr-xr-x  20 root root 4096 Jan 13 21:49 var
drwxr-xr-x   2 root root 4096 Jun  3 10:43 volume01
drwxr-xr-x   2 root root 4096 Jun  3 10:43 volume02

 我们再起一个容器docker2，然后去挂载docker1，可以看到docker2也有这两个挂载文件

[root@wangstudy ~]#docker run -it --name docker2 --volume from docker1 wang/centos
[root@8f9b5d163b8f /]# ls -l
total 56
lrwxrwxrwx   1 root root    7 May 11  2019 bin -> usr/bin
drwxr-xr-x   5 root root  360 Jun  3 10:43 dev
drwxr-xr-x   1 root root 4096 Jun  3 10:43 etc
drwxr-xr-x   2 root root 4096 May 11  2019 home
lrwxrwxrwx   1 root root    7 May 11  2019 lib -> usr/lib
lrwxrwxrwx   1 root root    9 May 11  2019 lib64 -> usr/lib64
drwx------   2 root root 4096 Jan 13 21:48 lost+found
drwxr-xr-x   2 root root 4096 May 11  2019 media
drwxr-xr-x   2 root root 4096 May 11  2019 mnt
drwxr-xr-x   2 root root 4096 May 11  2019 opt
dr-xr-xr-x 118 root root    0 Jun  3 10:43 proc
dr-xr-x---   2 root root 4096 Jan 13 21:49 root
drwxr-xr-x  11 root root 4096 Jan 13 21:49 run
lrwxrwxrwx   1 root root    8 May 11  2019 sbin -> usr/sbin
drwxr-xr-x   2 root root 4096 May 11  2019 srv
dr-xr-xr-x  13 root root    0 May 30 08:43 sys
drwxrwxrwt   7 root root 4096 Jan 13 21:49 tmp
drwxr-xr-x  12 root root 4096 Jan 13 21:49 usr
drwxr-xr-x  20 root root 4096 Jan 13 21:49 var
drwxr-xr-x   2 root root 4096 Jun  3 10:43 volume01
drwxr-xr-x   2 root root 4096 Jun  3 10:43 volume02

我们现在往docker1容器里加文件，来看docker2是否会存在文件,发现存在，所有挂载成功。

[root@wangstudy ~]# docker attach 5cd8cba5139d
[root@5cd8cba5139d /]# cd volume01
[root@5cd8cba5139d volume01]# ls
[root@5cd8cba5139d volume01]# touch docker01
[root@5cd8cba5139d volume01]# ls
docker01
[root@5cd8cba5139d volume01]# read escape sequence
[root@wangstudy ~]# docker attach 8f9b5d163b8f
[root@8f9b5d163b8f /]# cd volume01
[root@8f9b5d163b8f volume01]# ls
docker01

现在我们再创建docker3去挂载docker1，同样存在文件

[root@wangstudy ~]# docker run -it --name docker3 --volumes-from docker1 wang/centos
[root@7cc24ec1b075 /]# cd volume01
[root@7cc24ec1b075 volume01]# ls
docker01

如此，就实现了容器间数据共享，就算删掉docker1，数据依旧还在，相当于实现了数据备份。

[root@wangstudy ~]# docker stop 5cd8cba5139d
5cd8cba5139d
[root@wangstudy ~]# docker rm 5cd8cba5139d
5cd8cba5139d
[root@wangstudy ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
7cc24ec1b075        wang/centos         "/bin/sh -c /bin/bash"   6 minutes ago       Up 6 minutes                            docker3
8f9b5d163b8f        wang/centos         "/bin/sh -c /bin/bash"   19 minutes ago      Up 19 minutes                           docker2
[root@wangstudy ~]# docker attach 8f9b5d163b8f
[root@8f9b5d163b8f volume01]# ls
docker01  docker03
[root@8f9b5d163b8f volume01]#