现在 Docker 重启容器之后为什么修改过的东西还在？

去年中的时候玩过一段时间的 Docker，后来感觉对我没啥用就没完了。

这几天想复习下，就又开始玩了。

然后创建了一个容器：

docker container run -it --name=test centos 

在里面创建一个空白文件：

touch 111 

然后按 Ctrl+D 关闭容器。

再开启容器：

docker container start -a test 

然后查看文件：

ls 111 

会发现这个文件还在……

111 

为什么会这样，我记得以前我一重启容器里面的文件都会丢失的。

附上 inspect，好像里面也没使用数据卷。

[ { "Id": "f149e9ffd626dcffc86f3c8325abf0a7c3ddbd62e1834f4db652aae58a992dd4", "Created": "2018-04-02T08:01:58.043257934Z", "Path": "/bin/bash", "Args": [], "State": { "Status": "exited", "Running": false, "Paused": false, "Restarting": false, "OOMKilled": false, "Dead": false, "Pid": 0, "ExitCode": 0, "Error": "", "StartedAt": "2018-04-02T08:04:00.805282255Z", "FinishedAt": "2018-04-02T08:05:40.914734517Z" }, "Image": "sha256:2d194b392dd16955847a14f969b2dd319251471ffa6356be6d8f16c5bf53db9b", "ResolvConfPath": "/mnt/sda1/var/lib/docker/containers/f149e9ffd626dcffc86f3c8325abf0a7c3ddbd62e1834f4db652aae58a992dd4/resolv.conf", "HostnamePath": "/mnt/sda1/var/lib/docker/containers/f149e9ffd626dcffc86f3c8325abf0a7c3ddbd62e1834f4db652aae58a992dd4/hostname", "HostsPath": "/mnt/sda1/var/lib/docker/containers/f149e9ffd626dcffc86f3c8325abf0a7c3ddbd62e1834f4db652aae58a992dd4/hosts", "LogPath": "/mnt/sda1/var/lib/docker/containers/f149e9ffd626dcffc86f3c8325abf0a7c3ddbd62e1834f4db652aae58a992dd4/f149e9ffd626dcffc86f3c8325abf0a7c3ddbd62e1834f4db652aae58a992dd4-json.log", "Name": "/test", "RestartCount": 0, "Driver": "overlay2", "Platform": "linux", "MountLabel": "", "ProcessLabel": "", "AppArmorProfile": "", "ExecIDs": null, "HostConfig": { "Binds": null, "ContainerIDFile": "", "LogConfig": { "Type": "json-file", "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": "shareable", "Cgroup": "", "Links": null, "OomScoreAdj": 0, "PidMode": "", "Privileged": false, "PublishAllPorts": false, "ReadonlyRootfs": false, "SecurityOpt": null, "UTSMode": "", "UsernsMode": "", "ShmSize": 67108864, "Runtime": "runc", "ConsoleSize": [ 0, 0 ], "Isolation": "", "CpuShares": 0, "Memory": 0, "NanoCpus": 0, "CgroupParent": "", "BlkioWeight": 0, "BlkioWeightDevice": [], "BlkioDeviceReadBps": null, "BlkioDeviceWriteBps": null, "BlkioDeviceReadIOps": null, "BlkioDeviceWriteIOps": null, "CpuPeriod": 0, "CpuQuota": 0, "CpuRealtimePeriod": 0, "CpuRealtimeRuntime": 0, "CpusetCpus": "", "CpusetMems": "", "Devices": [], "DeviceCgroupRules": null, "DiskQuota": 0, "KernelMemory": 0, "MemoryReservation": 0, "MemorySwap": 0, "MemorySwappiness": null, "OomKillDisable": false, "PidsLimit": 0, "Ulimits": null, "CpuCount": 0, "CpuPercent": 0, "IOMaximumIOps": 0, "IOMaximumBandwidth": 0 }, "GraphDriver": { "Data": { "LowerDir": "/mnt/sda1/var/lib/docker/overlay2/3435bb5d5dbb430fcb6a9af122d0c5200de27131d5234aac3fc336c8d7070efd-init/diff:/mnt/sda1/var/lib/docker/overlay2/933b109e2e6219526f5393e8bca8dcadc22f592b41a5fcb8eadb52221eaf4838/diff", "MergedDir": "/mnt/sda1/var/lib/docker/overlay2/3435bb5d5dbb430fcb6a9af122d0c5200de27131d5234aac3fc336c8d7070efd/merged", "UpperDir": "/mnt/sda1/var/lib/docker/overlay2/3435bb5d5dbb430fcb6a9af122d0c5200de27131d5234aac3fc336c8d7070efd/diff", "WorkDir": "/mnt/sda1/var/lib/docker/overlay2/3435bb5d5dbb430fcb6a9af122d0c5200de27131d5234aac3fc336c8d7070efd/work" }, "Name": "overlay2" }, "Mounts": [], "Config": { "Hostname": "f149e9ffd626", "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": { "build-date": "20180302", "license": "GPLv2", "name": "CentOS Base Image", "vendor": "CentOS" } }, "NetworkSettings": { "Bridge": "", "SandboxID": "25cdd513903dff03fd8adfa4f8ebd1a61f75532eb23e493e23cb2350bda3de07", "HairpinMode": false, "LinkLocalIPv6Address": "", "LinkLocalIPv6PrefixLen": 0, "Ports": {}, "SandboxKey": "/var/run/docker/netns/25cdd513903d", "SecondaryIPAddresses": null, "SecondaryIPv6Addresses": null, "EndpointID": "", "Gateway": "", "GlobalIPv6Address": "", "GlobalIPv6PrefixLen": 0, "IPAddress": "", "IPPrefixLen": 0, "IPv6Gateway": "", "MacAddress": "", "Networks": { "bridge": { "IPAMConfig": null, "Links": null, "Aliases": null, "NetworkID": "a34d1f55d960138eedeaac53eb341429a1b69444abdeec387afe999c0c96b4f9", "EndpointID": "", "Gateway": "", "IPAddress": "", "IPPrefixLen": 0, "IPv6Gateway": "", "GlobalIPv6Address": "", "GlobalIPv6PrefixLen": 0, "MacAddress": "", "DriverOpts": null } } } } ]