Docker系列——Volume

it2023-08-20 65

Docker系列——Volume

Volume是什么？命令使用实战案例Docker之简单版Volume使用Docker之Volume结合权限的使用

Volume是什么？

Volume(数据卷)类似于Redis中的rdb和aof文件，主要用于宿主机和容器的数据共享，以及容器数据的持久化（当我们重启容器时，容器的所有数据会重置，数据卷除外）

命令使用

docker volume create [OPTIONS] [VOLUME]

实战案例

Docker之简单版Volume使用

我们安装一个Centos镜像

运行Centos并且挂载数据卷

查看宿主机根路径下的文件

查看Centos容器根目录下的文件

使用docker inspect [镜像ID] 查看容器信息

[ { "Id": "14eee0df6c9cb04f03bb828595aaf5423d0e800000be9b3a34ba2363ebdde528", "Created": "2020-10-20T12:12:33.363864083Z", "Path": "/bin/bash", "Args": [], "State": { "Status": "running", "Running": true, "Paused": false, "Restarting": false, "OOMKilled": false, "Dead": false, "Pid": 5979, "ExitCode": 0, "Error": "", "StartedAt": "2020-10-20T12:12:34.035988715Z", "FinishedAt": "0001-01-01T00:00:00Z" }, "Image": "sha256:0d120b6ccaa8c5e149176798b3501d4dd1885f961922497cd0abef155c869566", "ResolvConfPath": "/var/lib/docker/containers/14eee0df6c9cb04f03bb828595aaf5423d0e800000be9b3a34ba2363ebdde528/resolv.conf", "HostnamePath": "/var/lib/docker/containers/14eee0df6c9cb04f03bb828595aaf5423d0e800000be9b3a34ba2363ebdde528/hostname", "HostsPath": "/var/lib/docker/containers/14eee0df6c9cb04f03bb828595aaf5423d0e800000be9b3a34ba2363ebdde528/hosts", "LogPath": "", "Name": "/frosty_pare", "RestartCount": 0, "Driver": "devicemapper", "MountLabel": "system_u:object_r:svirt_sandbox_file_t:s0:c195,c365", "ProcessLabel": "system_u:system_r:svirt_lxc_net_t:s0:c195,c365", "AppArmorProfile": "", "ExecIDs": [ "ed27045ff827f60470f9289f08c19329c167605505bd3663226a004278e80f7d" ], "HostConfig": { "Binds": [ "/myData:/myContainerData" ], "ContainerIDFile": "", "LogConfig": { "Type": "journald", "Config": {} }, "NetworkMode": "default", "PortBindings": {}, "RestartPolicy": { "Name": "no", "MaximumRetryCount": 0 }, "AutoRemove": false, "VolumeDriver": "", "VolumesFrom": null, "CapAdd": null, "CapDrop": null, "Dns": [], "DnsOptions": [], "DnsSearch": [], "ExtraHosts": null, "GroupAdd": null, "IpcMode": "", "Cgroup": "", "Links": null, "OomScoreAdj": 0, "PidMode": "", "Privileged": false, "PublishAllPorts": false, "ReadonlyRootfs": false, "SecurityOpt": null, "UTSMode": "", "UsernsMode": "", "ShmSize": 67108864, "Runtime": "docker-runc", "ConsoleSize": [ 0, 0 ], "Isolation": "", "CpuShares": 0, "Memory": 0, "NanoCpus": 0, "CgroupParent": "", "BlkioWeight": 0, "BlkioWeightDevice": null, "BlkioDeviceReadBps": null, "BlkioDeviceWriteBps": null, "BlkioDeviceReadIOps": null, "BlkioDeviceWriteIOps": null, "CpuPeriod": 0, "CpuQuota": 0, "CpuRealtimePeriod": 0, "CpuRealtimeRuntime": 0, "CpusetCpus": "", "CpusetMems": "", "Devices": [], "DiskQuota": 0, "KernelMemory": 0, "MemoryReservation": 0, "MemorySwap": 0, "MemorySwappiness": -1, "OomKillDisable": false, "PidsLimit": 0, "Ulimits": null, "CpuCount": 0, "CpuPercent": 0, "IOMaximumIOps": 0, "IOMaximumBandwidth": 0 }, "GraphDriver": { "Name": "devicemapper", "Data": { "DeviceId": "13", "DeviceName": "docker-253:1-69090742-1554cac236d4473288a0e83d39a8795e843b9c1c4e6e0d259fda9461fbd1be2c", "DeviceSize": "10737418240" } }, "Mounts": [ { "Type": "bind", "Source": "/myData", "Destination": "/myContainerData", "Mode": "", "RW": true, "Propagation": "rprivate" } ], "Config": { "Hostname": "14eee0df6c9c", "Domainname": "", "User": "", "AttachStdin": true, "AttachStdout": true, "AttachStderr": true, "Tty": true, "OpenStdin": true, "StdinOnce": true, "Env": [ "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin" ], "Cmd": [ "/bin/bash" ], "ArgsEscaped": true, "Image": "centos", "Volumes": null, "WorkingDir": "", "Entrypoint": null, "OnBuild": null, "Labels": { "org.label-schema.build-date": "20200809", "org.label-schema.license": "GPLv2", "org.label-schema.name": "CentOS Base Image", "org.label-schema.schema-version": "1.0", "org.label-schema.vendor": "CentOS" } }, "NetworkSettings": { "Bridge": "", "SandboxID": "5ba83d9bf27236312f2213f09ece34240befb13cafde4d8e7e0413fe872f8112", "HairpinMode": false, "LinkLocalIPv6Address": "", "LinkLocalIPv6PrefixLen": 0, "Ports": {}, "SandboxKey": "/var/run/docker/netns/5ba83d9bf272", "SecondaryIPAddresses": null, "SecondaryIPv6Addresses": null, "EndpointID": "44f93ff134e5c88b66f87dd506bd593c3a373de2f6e2ae2e1bcb6318440a90d2", "Gateway": "172.17.0.1", "GlobalIPv6Address": "", "GlobalIPv6PrefixLen": 0, "IPAddress": "172.17.0.2", "IPPrefixLen": 16, "IPv6Gateway": "", "MacAddress": "02:42:ac:11:00:02", "Networks": { "bridge": { "IPAMConfig": null, "Links": null, "Aliases": null, "NetworkID": "9898e099943ce74838009d4944decb94e6fe9e0137338bafcae845dc5be535d8", "EndpointID": "44f93ff134e5c88b66f87dd506bd593c3a373de2f6e2ae2e1bcb6318440a90d2", "Gateway": "172.17.0.1", "IPAddress": "172.17.0.2", "IPPrefixLen": 16, "IPv6Gateway": "", "GlobalIPv6Address": "", "GlobalIPv6PrefixLen": 0, "MacAddress": "02:42:ac:11:00:02" } } } } ]

我们可以看到Mounts中的属性（新版的Docker才有这个属性），这里面是我们的文件配置信息，Source——主机中挂载路径的绝对路径，Destination——容器中数据卷的绝对路径，RW——容器对数据卷进行读写的权限，Model——模式

此时在宿主机挂载的目录下创建文件，然后查看容器里面的数据卷发现也有对应的数据。

此时就算我们关闭容器，在宿主机的挂载路径下创建一个helloword01.text,然后再启动容器，我们再容器中的数据卷目录下也会有对应的helloword01.text文件

Docker之Volume结合权限的使用

我们使用:ro添加只可读的权限，就可以看到我们再容器中的挂载卷下创建卷失败，因为容器没有可写的权限我们也可以用docker inspect 镜像ID查看Mounts中的属性 "Mounts": [ { "Type": "bind", "Source": "/myData", "Destination": "/myContainerData", "Mode": "ro", "RW": false, "Propagation": "rprivate" } ]

Mode变为ro了，RW可读可写的权限也变为了false

本文纯属个人理解，如有错误，欢迎请大家指出~~~

最新回复(0)