Docker是怎么工作的？
Docker是一个Client - Server 结构的系统，Docker的守护进程运行在宿主机上，通过Socket从客户端访问。Docker-Server收到Docker-Client的指令，就会执行命令。
Docker为什么比VM快？
1.Docker有更少的抽象层
2.Docker利用的是宿主机的内核，VM需要Guest OS(操作系统内核)
帮助命令
docker version
docker info #系统信息，包括镜像和容器的数量
docker xxx --help官方文档：https://docs.docker.com/refer...
镜像命令
docker images --helpdocker images 查看所有本地镜像
REPOSITORY TAG IMAGE ID CREATED SIZE
hello-world latest d1165f221234 4 months ago 13.3kB
REPOSITORY #镜像仓库源
TAG #镜像标签
IMAGE ID #镜像ID
CREATED #镜像创建时间
SIZE #镜像大小
#可选项
-a --all #列出所有镜像
-q --quiet #只显示镜像ID docker search 搜索镜像
docker search mysql
#可选项
-f --filter #过滤条件
--fitler=STARS=3000 #收藏3000以上的镜像docker pull 下载镜像
Dockerhub地址：https://hub.docker.com
docker pull [OPTIONS] NAME[:TAG|@DIGEST]
OPTIONS #可选项
NAME #镜像名
TAG #镜像标签
#指定版本下载
docker pull mysql:5.7docker rmi 删除镜像
docker rmi -f 容器ID1 ... 容器IDN
#删除全部镜像
docker rmi -f $(docker images -aq)容器命令
docker run 新建并启动容器
docker run [OPTIONS] IMAGE [COMMAND] [ARG...]
#参数说明
--name #容器名
-d #后台方式运行
-it #交互方式运行，进入容器查看
-p #指定容器端口
-P #随机指定端口
#测试：启动并进入容器
docker pull centos
docker run -it centos /bin/bash
#退出容器
exit #容器停止并退出
CTRL + P + Q #不停止退出docker ps 列出容器
docker ps #列出当前正在运行的容器
-a #列出当前正在运行的容器+历史运行过的容器
-n=? #最近创建的容器
-q #只显示容器编号docker rm 删除容器
docker rm 容器ID
docker rm $(docker ps -aq) #删除所有容器
-f #强制删除（包括运行中的容器）docker start 启动容器
docker start 容器ID
docker restart 容器ID
docker stop 容器ID
docker kill 容器IDdocker logs 查看日志
docker logs -tf --tail 10 容器ID #显示指定行数
docker logs -t -f 容器ID #显示日志docker top 查看进程
docker top 容器IDdocker inspect 查看元数据
docker inspect 容器ID
[
{
"Id": "d3b9799417b69391ba9bdd644b7a5604780cecc371a6511a62b5503d063c3e63",
"Created": "2021-07-29T23:22:16.737750806Z",
"Path": "/bin/bash",
"Args": [],
"State": {
"Status": "exited",
"Running": false,
"Paused": false,
"Restarting": false,
"OOMKilled": false,
"Dead": false,
"Pid": 0,
"ExitCode": 137,
"Error": "",
"StartedAt": "2021-07-29T23:31:58.686730736Z",
"FinishedAt": "2021-07-29T23:32:10.840176294Z"
},
"Image": "sha256:300e315adb2f96afe5f0b2780b87f28ae95231fe3bdd1e16b9ba606307728f55",
"ResolvConfPath": "/var/lib/docker/containers/d3b9799417b69391ba9bdd644b7a5604780cecc371a6511a62b5503d063c3e63/resolv.conf",
"HostnamePath": "/var/lib/docker/containers/d3b9799417b69391ba9bdd644b7a5604780cecc371a6511a62b5503d063c3e63/hostname",
"HostsPath": "/var/lib/docker/containers/d3b9799417b69391ba9bdd644b7a5604780cecc371a6511a62b5503d063c3e63/hosts",
"LogPath": "/var/lib/docker/containers/d3b9799417b69391ba9bdd644b7a5604780cecc371a6511a62b5503d063c3e63/d3b9799417b69391ba9bdd644b7a5604780cecc371a6511a62b5503d063c3e63-json.log",
"Name": "/optimistic_bartik",
"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,
"CgroupnsMode": "host",
"Dns": [],
"DnsOptions": [],
"DnsSearch": [],
"ExtraHosts": null,
"GroupAdd": null,
"IpcMode": "private",
"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,
"DeviceRequests": null,
"KernelMemory": 0,
"KernelMemoryTCP": 0,
"MemoryReservation": 0,
"MemorySwap": 0,
"MemorySwappiness": null,
"OomKillDisable": false,
"PidsLimit": null,
"Ulimits": null,
"CpuCount": 0,
"CpuPercent": 0,
"IOMaximumIOps": 0,
"IOMaximumBandwidth": 0,
"MaskedPaths": [
"/proc/asound",
"/proc/acpi",
"/proc/kcore",
"/proc/keys",
"/proc/latency_stats",
"/proc/timer_list",
"/proc/timer_stats",
"/proc/sched_debug",
"/proc/scsi",
"/sys/firmware"
],
"ReadonlyPaths": [
"/proc/bus",
"/proc/fs",
"/proc/irq",
"/proc/sys",
"/proc/sysrq-trigger"
]
},
"GraphDriver": {
"Data": {
"LowerDir": "/var/lib/docker/overlay2/fd5fe8080f2c13c00311711f4e51865588f39c784047fcdce26d4611f6128587-init/diff:/var/lib/docker/overlay2/27c6cfd367d905528b550279efab95fa7f52c97abb12625131c408b6dea72fe7/diff",
"MergedDir": "/var/lib/docker/overlay2/fd5fe8080f2c13c00311711f4e51865588f39c784047fcdce26d4611f6128587/merged",
"UpperDir": "/var/lib/docker/overlay2/fd5fe8080f2c13c00311711f4e51865588f39c784047fcdce26d4611f6128587/diff",
"WorkDir": "/var/lib/docker/overlay2/fd5fe8080f2c13c00311711f4e51865588f39c784047fcdce26d4611f6128587/work"
},
"Name": "overlay2"
},
"Mounts": [],
"Config": {
"Hostname": "d3b9799417b6",
"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"
],
"Image": "centos",
"Volumes": null,
"WorkingDir": "",
"Entrypoint": null,
"OnBuild": null,
"Labels": {
"org.label-schema.build-date": "20201204",
"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": "0ac7744565902b645737fcc3eabd47c9c27a7babaa0856ec55e466a7237e6ba8",
"HairpinMode": false,
"LinkLocalIPv6Address": "",
"LinkLocalIPv6PrefixLen": 0,
"Ports": {},
"SandboxKey": "/var/run/docker/netns/0ac774456590",
"SecondaryIPAddresses": null,
"SecondaryIPv6Addresses": null,
"EndpointID": "",
"Gateway": "",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"IPAddress": "",
"IPPrefixLen": 0,
"IPv6Gateway": "",
"MacAddress": "",
"Networks": {
"bridge": {
"IPAMConfig": null,
"Links": null,
"Aliases": null,
"NetworkID": "2d10dc4aa739ceb9a9aad3c64688a40431ff71e5dfaed298ec83265434d7863c",
"EndpointID": "",
"Gateway": "",
"IPAddress": "",
"IPPrefixLen": 0,
"IPv6Gateway": "",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"MacAddress": "",
"DriverOpts": null
}
}
}
}
]docker exec\attach 进入当前正在运行的容器
docker exec -it 容器ID /bin/bash
#进入容器后开启新的终端，可以操作
docker attach 容器ID
#进入容器正在执行的终端，不会启动新的进程docker cp 拷贝文件
docker cp 容器ID:容器内路径 宿主机路径其他
docker run -d 容器ID
docker ps 发现容器停止了
原因：docker容器在后台运行，必须有一个前台进程，如果docker发现没有应用，就会自动停止小结
