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Docker|3.文件、数据共享

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文件拷贝

docker cp 容器ID:/文件路径/文件名称 本地文件路径

**docker cp 本地文件路径 容器ID:/文件路径/文件名称 **

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#从容器内拷贝文件到本地
[root@localhost ~]# docker cp cd7a272e8786:/etc/passwd /tmp
[root@localhost ~]# head -3 /tmp/passwd 
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
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#将本地文件拷贝到容器内
[root@localhost ~]# echo "123" > file1
[root@localhost ~]# docker cp file1 cd7a272e8786:/tmp
[root@localhost ~]# docker exec -it cd7a272e8786 cat /tmp/file1
123

数据卷

-v命令实现

docker run -it -v /宿主机的绝对路径目录:/容器内目录 镜像名 #如果不能写，需要添加–privileged=true

docker run -it -v /宿主机的绝对路径目录:/容器内目录:ro 镜像名 #容器内文件只读

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[root@localhost ~]# docker run --name centos0211 -it -v /HostDataVolume:/ContainerDataVolume centos
[root@cde93366c404 /]# cd /ContainerDataVolume/
[root@cde93366c404 ContainerDataVolume]# ls
[root@cde93366c404 ContainerDataVolume]# echo "123" > file1
[root@cde93366c404 ContainerDataVolume]# exit
exit
[root@localhost ~]# cat /HostDataVolume/file1 
123

dockerfile方式数据卷

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vim /root/mydocker/Dockerfile
#volume test
FROM centos
VOLUME ["/DataVolumeContainer1","/DataVolumeContainer2"]
CMD echo "finished, ------success!"
CMD /bin/bash
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[root@localhost mydocker]# docker build -f /root/mydocker/Dockerfile -t test/centos .
Sending build context to Docker daemon  2.048kB
Step 1/4 : FROM centos
 ---> 470671670cac
Step 2/4 : VOLUME ["/DataVolumeContainer1","/DataVolumeContainer2"]
 ---> Running in ad5cdf37264a
Removing intermediate container ad5cdf37264a
 ---> 3e834cfa3923
Step 3/4 : CMD echo "finished, ------success!"
 ---> Running in 033f927a7220
Removing intermediate container 033f927a7220
 ---> d1b3cc53d482
Step 4/4 : CMD /bin/bash
 ---> Running in 47ebcfb99158
Removing intermediate container 47ebcfb99158
 ---> c8ed8caf62e2
Successfully built c8ed8caf62e2
Successfully tagged test/centos:latest
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[root@localhost mydocker]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
test/centos         latest              c8ed8caf62e2        10 seconds ago      237MB
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[root@localhost mydocker]# docker run -it test/centos
[root@7f54ea649e73 /]# ls -l
total 16
drwxr-xr-x   2 root root    6 Feb 11 23:18 DataVolumeContainer1
drwxr-xr-x   2 root root    6 Feb 11 23:18 DataVolumeContainer2
……
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[root@localhost ~]# docker inspect 7f54ea649e73
……
……
"Mounts": [
            {
                "Type": "volume",
                "Name": "db383db0ed0f634dca3b88ac7b1b5eb7aaf1eb45aa5e198c1dbb672717cbadc4",
                "Source": "/var/lib/docker/volumes/db383db0ed0f634dca3b88ac7b1b5eb7aaf1eb45aa5e198c1dbb672717cbadc4/_data",
                "Destination": "/DataVolumeContainer1",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            },
            {
                "Type": "volume",
                "Name": "ed238e4c4a3bf80274f6bd6dd5d4a1aa00020e081a38d9ae668567d9a9301344",
                "Source": "/var/lib/docker/volumes/ed238e4c4a3bf80274f6bd6dd5d4a1aa00020e081a38d9ae668567d9a9301344/_data",
                "Destination": "/DataVolumeContainer2",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }
……
……
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[root@7f54ea649e73 /]# echo "123" > /DataVolumeContainer1/file1
[root@localhost ~]# cat /var/lib/docker/volumes/db383db0ed0f634dca3b88ac7b1b5eb7aaf1eb45aa5e198c1dbb672717cbadc4/_data/file1 
123

数据卷容器

命名的容器挂载数据卷，其他容器通过挂载这个（父容器）实现数据共享，挂载数据卷的容器，称之为数据卷容器。

先启动一个父容器

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[root@localhost ~]# docker run -it --name dc01 test/centos

[root@fe649066e76e /]# cd DataVolumeContainer1/

[root@fe649066e76e DataVolumeContainer1]# touch add_dc01.txt

新建dc02/dc03容器，继承dc01

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#新建dc02

[root@localhost ~]# docker run -it --name dc02 --volumes-from dc01 test/centos

[root@c14197144fe7 /]# cd /DataVolumeContainer1/

[root@c14197144fe7 DataVolumeContainer1]# touch add_dc02.txt

#新建dc03

[root@localhost ~]# docker run -it --name dc03 --volumes-from dc01 test/centos

[root@c409dacf9084 /]# cd /DataVolumeContainer1/

[root@c409dacf9084 DataVolumeContainer1]# touch add_dc03.txt

在dc01上查看数据

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[root@localhost ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
c409dacf9084        test/centos         "/bin/sh -c /bin/bash"   4 minutes ago       Up 4 minutes                            dc03
c14197144fe7        test/centos         "/bin/sh -c /bin/bash"   4 minutes ago       Up 4 minutes                            dc02
fe649066e76e        test/centos         "/bin/sh -c /bin/bash"   9 minutes ago       Up 9 minutes                            dc01
[root@localhost ~]# docker attach fe649066e76e
[root@fe649066e76e DataVolumeContainer1]# ls -l
total 0
-rw-r--r-- 1 root root 0 Feb 12 00:02 add_dc01.txt
-rw-r--r-- 1 root root 0 Feb 12 00:09 add_dc02.txt
-rw-r--r-- 1 root root 0 Feb 12 00:10 add_dc03.txt

删除dc01,在dc02上添加数据，在dc03上查看

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[root@localhost ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
c409dacf9084        test/centos         "/bin/sh -c /bin/bash"   5 minutes ago       Up 5 minutes                            dc03
c14197144fe7        test/centos         "/bin/sh -c /bin/bash"   5 minutes ago       Up 5 minutes                            dc02
fe649066e76e        test/centos         "/bin/sh -c /bin/bash"   10 minutes ago      Up 10 minutes                           dc01
[root@localhost ~]# docker rm -f fe649066e76e
fe649066e76e
[root@localhost ~]# docker attach c14197144fe7
[root@c14197144fe7 DataVolumeContainer1]# ls -l
total 0
-rw-r--r-- 1 root root 0 Feb 12 00:02 add_dc01.txt
-rw-r--r-- 1 root root 0 Feb 12 00:09 add_dc02.txt
-rw-r--r-- 1 root root 0 Feb 12 00:10 add_dc03.txt
[root@c14197144fe7 DataVolumeContainer1]# touch update_dc02.txt

[root@localhost ~]# docker attach dc03
[root@c409dacf9084 DataVolumeContainer1]# ls -l
total 0
-rw-r--r-- 1 root root 0 Feb 12 00:02 add_dc01.txt
-rw-r--r-- 1 root root 0 Feb 12 00:09 add_dc02.txt
-rw-r--r-- 1 root root 0 Feb 12 00:10 add_dc03.txt
-rw-r--r-- 1 root root 0 Feb 12 00:13 update_dc02.txt

删除dc02，测试dc03数据是否可以访问

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[root@localhost ~]# docker rm -f dc02
dc02
[root@localhost ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
c409dacf9084        test/centos         "/bin/sh -c /bin/bash"   10 minutes ago      Up 10 minutes                           dc03
[root@localhost ~]# docker attach dc03
[root@c409dacf9084 DataVolumeContainer1]# ls -l
total 0
-rw-r--r-- 1 root root 0 Feb 12 00:02 add_dc01.txt
-rw-r--r-- 1 root root 0 Feb 12 00:09 add_dc02.txt
-rw-r--r-- 1 root root 0 Feb 12 00:10 add_dc03.txt
-rw-r--r-- 1 root root 0 Feb 12 00:13 update_dc02.txt

新建dc04继承dc03，然后删除dc03

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[root@localhost ~]# docker run -it --name dc04 --volumes-from dc03 test/centos
[root@localhost ~]# docker rm -f dc03
dc03
[root@localhost ~]# docker ps 
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
5156e4538e53        test/centos         "/bin/sh -c /bin/bash"   59 seconds ago      Up 58 seconds                           dc04
[root@localhost ~]# docker attach dc04
[root@5156e4538e53 DataVolumeContainer1]# cd /DataVolumeContainer1/
[root@5156e4538e53 DataVolumeContainer1]# ls -l
total 0
-rw-r--r-- 1 root root 0 Feb 12 00:02 add_dc01.txt
-rw-r--r-- 1 root root 0 Feb 12 00:09 add_dc02.txt
-rw-r--r-- 1 root root 0 Feb 12 00:10 add_dc03.txt
-rw-r--r-- 1 root root 0 Feb 12 00:13 update_dc02.txt

结论：容器之间配置信息的传递，数据卷的生命周期一直持续到没有容器使用它为止