docker容器数据卷

1.背景

通俗的理解就是容器运行中产生的数据会随着容器关闭而消失，所以我们希望使用卷（磁盘）来保存,大家可以理解为业务数据，与镜像无关；

特点：

1.卷中的更改可以直接生效

2.数据卷中的更改不会包含在镜像的更新中

3.数据卷可在容器之间共享或重用数据

4.数据卷的生命周期一直持续到没有容器使用它为止

本质：主机与容器数据共享

2.简单使用

执行命令：

docker run -it -v /h-dada01:/c-dada01 centos /bin/bash

/h-dada01 表示主机中的磁盘位置

/c-dada01 表示容器中的磁盘位置

这个两个文件加的内容会实时共享同步，

即：在容器中的c-dada01 增加或修改文件，在主机中的h-dada01也会跟着变，反过来也一样,

大家可以自己再文件中操作观察结果

容器中：

主机中：

注意：

学到这里，可能有的童鞋会问，

如果把容器关了，然后直接在主机里面修改文件，即修改h-data01里面的内容，

那么当容器再次启动后，c-dada01里面的数据会同步更新么？

答案是会改变的，因为是实时同步的，大家可以自己测试。

3.查看挂载情况

docker inspect 容器id

 内容太多，不能完整的截图，直接把内容拷贝出来如下：

[root@localhost h-dada01]# docker inspect 5803a2ce204e
[
{
    "Id": "5803a2ce204eb107a7c47a2ef1c554d04ce70effeac1cd3dc9de4c46f94f48e2",
    "Created": "2020-08-07T13:13:01.776487Z",
    "Path": "/bin/bash",
    "Args": [],
    "State": {
        "Running": true,
        "Paused": false,
        "Restarting": false,
        "OOMKilled": false,
        "Dead": false,
        "Pid": 11709,
        "ExitCode": 0,
        "Error": "",
        "StartedAt": "2020-08-07T13:13:02.4827852Z",
        "FinishedAt": "0001-01-01T00:00:00Z"
    },
    "Image": "86ac386aa02e523765549ff1f78f226464865c941a0dec5ccd33149024d23ad5",
    "NetworkSettings": {
        "Bridge": "",
        "EndpointID": "bf4f04bdc2881896c9329644ded148e243f2288f08279f7d65d6b86286e6c50d",
        "Gateway": "172.17.42.1",
        "GlobalIPv6Address": "",
        "GlobalIPv6PrefixLen": 0,
        "HairpinMode": false,
        "IPAddress": "172.17.0.9",
        "IPPrefixLen": 16,
        "IPv6Gateway": "",
        "LinkLocalIPv6Address": "",
        "LinkLocalIPv6PrefixLen": 0,
        "MacAddress": "02:42:ac:11:00:09",
        "NetworkID": "d548d190550d9f5933f92e5843f0f27f69ae038b4313503ad73422cf089357be",
        "PortMapping": null,
        "Ports": {},
        "SandboxKey": "/var/run/docker/netns/5803a2ce204e",
        "SecondaryIPAddresses": null,
        "SecondaryIPv6Addresses": null
    },
    "ResolvConfPath": "/var/lib/docker/containers/5803a2ce204eb107a7c47a2ef1c554d04ce70effeac1cd3dc9de4c46f94f48e2/resolv.conf",
    "HostnamePath": "/var/lib/docker/containers/5803a2ce204eb107a7c47a2ef1c554d04ce70effeac1cd3dc9de4c46f94f48e2/hostname",
    "HostsPath": "/var/lib/docker/containers/5803a2ce204eb107a7c47a2ef1c554d04ce70effeac1cd3dc9de4c46f94f48e2/hosts",
    "LogPath": "/var/lib/docker/containers/5803a2ce204eb107a7c47a2ef1c554d04ce70effeac1cd3dc9de4c46f94f48e2/5803a2ce204eb107a7c47a2ef1c554d04ce70effeac1cd3dc9de4c46f94f48e2-json.log",
    "Name": "/gloomy_darwin",
    "RestartCount": 0,
    "Driver": "devicemapper",
    "ExecDriver": "native-0.2",
    "MountLabel": "",
    "ProcessLabel": "",
    "Volumes": {
        "/c-dada01": "/h-dada01"
    },
    "VolumesRW": {
        "/c-dada01": true
    },
    "AppArmorProfile": "",
    "ExecIDs": null,
    "HostConfig": {
        "Binds": [
            "/h-dada01:/c-dada01"
        ],
        "ContainerIDFile": "",
        "LxcConf": [],
        "Memory": 0,
        "MemorySwap": 0,
        "CpuShares": 0,
        "CpuPeriod": 0,
        "CpusetCpus": "",
        "CpusetMems": "",
        "CpuQuota": 0,
        "BlkioWeight": 0,
        "OomKillDisable": false,
        "Privileged": false,
        "PortBindings": {},
        "Links": null,
        "PublishAllPorts": false,
        "Dns": null,
        "DnsSearch": null,
        "ExtraHosts": null,
        "VolumesFrom": null,
        "Devices": [],
        "NetworkMode": "bridge",
        "IpcMode": "",
        "PidMode": "",
        "UTSMode": "",
        "CapAdd": null,
        "CapDrop": null,
        "RestartPolicy": {
            "Name": "no",
            "MaximumRetryCount": 0
        },
        "SecurityOpt": null,
        "ReadonlyRootfs": false,
        "Ulimits": null,
        "LogConfig": {
            "Type": "json-file",
            "Config": {}
        },
        "CgroupParent": ""
    },
    "Config": {
        "Hostname": "5803a2ce204e",
        "Domainname": "",
        "User": "",
        "AttachStdin": true,
        "AttachStdout": true,
        "AttachStderr": true,
        "PortSpecs": null,
        "ExposedPorts": null,
        "Tty": true,
        "OpenStdin": true,
        "StdinOnce": true,
        "Env": [
            "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
        ],
        "Cmd": [
            "/bin/bash"
        ],
        "Image": "centos",
        "Volumes": null,
        "VolumeDriver": "",
        "WorkingDir": "",
        "Entrypoint": null,
        "NetworkDisabled": false,
        "MacAddress": "",
        "OnBuild": null,
        "Labels": {
            "org.label-schema.build-date": "20200611",
            "org.label-schema.license": "GPLv2",
            "org.label-schema.name": "CentOS Base Image",
            "org.label-schema.schema-version": "1.0",
            "org.label-schema.vendor": "CentOS"
        }
    }
}
]
[root@localhost h-dada01]#

重点是可以看这句：

4.挂载磁盘权限控制

 主机可读可写，容器只可以读

执行命令：docker run -it -v /h-dada02-rw:/c-dada02-ro:ro centos /bin/bash

/h-dada02-rw ，主机共享文件夹名称，只是为了便于理解加了一个-rw,原则上可以任意取名称

/c-dada02-ro ，容器中共享文件夹名称，只是为了便于理解加了一个-ro,原则上可以任意取名称

ro ,执行命令的参数表示可读，ro(read only)

 

 大家可以自己测试：

在主机文件夹h-dada02-rw，添加或修改文件，能正常操作；

在容器文件夹c-dada02-ro，添加或修改文件，不能正常操作；

查看挂载情况

docker inspect a21b03b3b8f5

系统化学习docker教程：

https://www.cnblogs.com/newAndHui/p/13508771.html