Docker 05 常用命令
启动 Docker
systemctl start docker
在服务器关机或者重启后，是需要重新启动 Docker 的。 命令如下：
systemctl start docker
查看日志
docker logs
语法：
docker logs [参数] 容器
参数：
-f：日志流动输出。-t：展示时间戳。--tail：从日志末尾显示的行数。
为模拟日志输出效果，我们先编写一段脚本：
while true;do echo sail;sleep 3;done
以上脚本实现的效果为：每隔 3 秒输出字符串 sail。
以脚本启动容器：
[root@sail ~]# docker run -d centos /bin/sh -c "while true;do echo sail;sleep 3;done"
c3d59f55d600566a5bbd9411ce716fbd338efc1c7c991f5baf1152f021d7e151
[root@sail ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c3d59f55d600 centos "/bin/sh -c 'while t…" 7 seconds ago Up 7 seconds musing_poincare
[root@sail ~]# docker logs -f -t --tail 10 c3d59f55d600
2021-12-10T03:01:28.607288480Z sail
2021-12-10T03:01:31.609334595Z sail
2021-12-10T03:01:34.611361943Z sail
2021-12-10T03:01:37.613461457Z sail
2021-12-10T03:01:40.615619089Z sail
2021-12-10T03:01:43.617595572Z sail
2021-12-10T03:01:46.619526233Z sail
2021-12-10T03:01:49.621856800Z sail
2021-12-10T03:01:52.623864131Z sail
2021-12-10T03:01:55.626146643Z sail
2021-12-10T03:01:58.628272273Z sail
2021-12-10T03:02:01.630370420Z sail
2021-12-10T03:02:04.632430066Z sail
2021-12-10T03:02:07.634690353Z sail
2021-12-10T03:02:10.636760025Z sail
可以看到，按此命令会看到容器最后 10 条日志，且每隔 3 秒滚动输出一条日志。
后台启动
docker run -d
语法：
docker run -d 镜像
后台启动镜像：
[root@sail ~]# docker run -d centos
0aee6f74b913f120195ca323892867bba7d72f2671f2f8b17278a3e029ad5bfd
[root@sail ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
使用 docker run -d 启动，也并不能保证容器一定能在后台运行，如果没有前台使用，容器启动后发现自己没有提供服务，会立刻停止。
前面的 docker run -d centos /bin/sh -c "while true;do echo sail;sleep 3;done" 命令，由于启动后运行了脚本打印日志，即提供了服务，所以不会停止。
查看容器信息
docker inspect
语法：
docker inspect 容器
示例：
[root@sail ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c3d59f55d600 centos "/bin/sh -c 'while t…" 24 minutes ago Up 5 seconds musing_poincare
[root@sail ~]# docker inspect c3d59f55d600
[
{
"Id": "c3d59f55d600566a5bbd9411ce716fbd338efc1c7c991f5baf1152f021d7e151", # 容器的完整ID
"Created": "2021-12-10T02:59:43.245101004Z", # 创建时间
"Path": "/bin/sh", # 脚本位置
"Args": [ # 运行的脚本
"-c",
"while true;do echo sail;sleep 3;done"
],
"State": {
"Status": "running", # 状态：正在运行
"Running": true,
"Paused": false,
"Restarting": false,
"OOMKilled": false,
"Dead": false,
"Pid": 31277, # 父进程ID
"ExitCode": 0,
"Error": "",
"StartedAt": "2021-12-10T03:23:37.744951214Z",
"FinishedAt": "2021-12-10T03:04:59.090158114Z"
},
"Image": "sha256:5d0da3dc976460b72c77d94c8a1ad043720b0416bfc16c52c45d4847e53fadb6", # 来源镜像
"ResolvConfPath": "/var/lib/docker/containers/c3d59f55d600566a5bbd9411ce716fbd338efc1c7c991f5baf1152f021d7e151/resolv.conf",
"HostnamePath": "/var/lib/docker/containers/c3d59f55d600566a5bbd9411ce716fbd338efc1c7c991f5baf1152f021d7e151/hostname",
"HostsPath": "/var/lib/docker/containers/c3d59f55d600566a5bbd9411ce716fbd338efc1c7c991f5baf1152f021d7e151/hosts",
"LogPath": "/var/lib/docker/containers/c3d59f55d600566a5bbd9411ce716fbd338efc1c7c991f5baf1152f021d7e151/c3d59f55d600566a5bbd9411ce716fbd338efc1c7c991f5baf1152f021d7e151-json.log",
"Name": "/musing_poincare",
"RestartCount": 0,
"Driver": "overlay2",
"Platform": "linux",
"MountLabel": "",
"ProcessLabel": "",
"AppArmorProfile": "",
"ExecIDs": null,
"HostConfig": { # 主机配置
"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": { # 其他配置
"Data": {
"LowerDir": "/var/lib/docker/overlay2/ed38d7c2061c4ebc46138b1e181e8286c0ca9242292945be7e2d4a9cef77eb48-init/diff:/var/lib/docker/overlay2/03139488f80fb2bbb139709a63d45233d63ef0258452b719b74f23e78a6aca7c/diff",
"MergedDir": "/var/lib/docker/overlay2/ed38d7c2061c4ebc46138b1e181e8286c0ca9242292945be7e2d4a9cef77eb48/merged",
"UpperDir": "/var/lib/docker/overlay2/ed38d7c2061c4ebc46138b1e181e8286c0ca9242292945be7e2d4a9cef77eb48/diff",
"WorkDir": "/var/lib/docker/overlay2/ed38d7c2061c4ebc46138b1e181e8286c0ca9242292945be7e2d4a9cef77eb48/work"
},
"Name": "overlay2"
},
"Mounts": [], # 挂载
"Config": { # 基本配置
"Hostname": "c3d59f55d600",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [ # 基本环境变量
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
],
"Cmd": [ # 基本命令
"/bin/sh",
"-c",
"while true;do echo sail;sleep 3;done"
],
"Image": "centos",
"Volumes": null,
"WorkingDir": "",
"Entrypoint": null,
"OnBuild": null,
"Labels": {
"org.label-schema.build-date": "20210915",
"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": { # 网卡设置
"Bridge": "",
"SandboxID": "421b87a4fcfaff65125a707b61b1ba88aa9fc731c452a66f8f1731131721a90a",
"HairpinMode": false,
"LinkLocalIPv6Address": "",
"LinkLocalIPv6PrefixLen": 0,
"Ports": {},
"SandboxKey": "/var/run/docker/netns/421b87a4fcfa",
"SecondaryIPAddresses": null,
"SecondaryIPv6Addresses": null,
"EndpointID": "3c3fce24d19469194202087ff3fe08135ebdc969773c75300c54db4190609467",
"Gateway": "172.17.0.1",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"IPAddress": "172.17.0.4",
"IPPrefixLen": 16,
"IPv6Gateway": "",
"MacAddress": "02:42:ac:11:00:04",
"Networks": {
"bridge": { # 桥接类型网卡
"IPAMConfig": null,
"Links": null,
"Aliases": null,
"NetworkID": "f3eeb014197a66bb6d740738f4e8148db7f8cb6c0b7432e429ff61a0cf5e0b06",
"EndpointID": "3c3fce24d19469194202087ff3fe08135ebdc969773c75300c54db4190609467",
"Gateway": "172.17.0.1",
"IPAddress": "172.17.0.4",
"IPPrefixLen": 16,
"IPv6Gateway": "",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"MacAddress": "02:42:ac:11:00:04",
"DriverOpts": null
}
}
}
}
]
不管容器是否运行，都可以使用该命令查看。
进入正在运行的容器
容器是一个微型的 Linux 系统，我们通常需要进入容器进行操作。
docker exec
使用 docker exec 可以进入容器并开启一个新的终端，可以在里面操作。
语法：
docker exec [参数] 容器 路径
参数：
-d：后台运行。-it：交互模式进入。
[root@sail ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
96ed3fe3e7f1 centos "/bin/bash" 15 hours ago Up 15 hours centos01
[root@sail ~]# docker exec -it 96ed3fe3e7f1 /bin/bash
[root@96ed3fe3e7f1 /]# ls
bin dev etc home lib lib64 lost+found media mnt opt proc root run sbin srv sys tmp usr var
[root@96ed3fe3e7f1 /]# ps -ef
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 Dec09 pts/0 00:00:00 /bin/bash
root 15 0 0 03:38 pts/1 00:00:00 /bin/bash
root 30 15 0 03:39 pts/1 00:00:00 ps -ef
这种进入方式是单独开了一个新进程的方式。
docker attach
使用 docker attach 会进入容器正在执行的终端，不会启动新的进程。
语法：
docker attach 容器
[root@sail ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
96ed3fe3e7f1 centos "/bin/bash" 17 hours ago Up 17 hours centos01
[root@sail ~]# docker attach 96ed3fe3e7f1
[root@96ed3fe3e7f1 /]# ps -ef
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 Dec09 pts/0 00:00:00 /bin/bash
root 33 1 0 05:49 pts/0 00:00:00 ps -ef
这种进入方式没有开启新的进程（/bin/bash 是 centos 容器的默认终端）。
从容器内拷贝文件到主机
查看启动的容器：
[root@sail ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
96ed3fe3e7f1 centos "/bin/bash" 17 hours ago Up 17 hours centos01
进入容器，创建一个文件：
[root@sail ~]# docker attach 96ed3fe3e7f1
[root@96ed3fe3e7f1 /]# cd /home
[root@96ed3fe3e7f1 home]# touch test.java
[root@96ed3fe3e7f1 home]# ls
test.java
[root@96ed3fe3e7f1 home]# exit
exit
退出容器后，不管容器是否启动，都可以复制容器中的文件到主机上：
[root@sail ~]# cd /home
[root@sail home]# docker cp 96ed3fe3e7f1:/home/test.java /home
[root@sail home]# ls
admin f2 f3 sail test.java
这种方式是一个手动过程，很不方便，推荐使用数据卷技术，可以实现自动同步主机和容器的目录。
详情见：Docker 12 数据卷
查看Docker内存占用
docker stats
语法：
docker stats [参数] [容器...]
参数：
-a：查看所有容器的内存占用（默认只展示运行的容器）。
查看运行的容器状态：
docker stats
[root@sail home]# docker stats
CONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS
96ed3fe3e7f1 centos01 0.00% 524KiB / 1.694GiB 0.03% 0B / 0B 0B / 0B 1
查看全部容器状态：
docker stats -a
[root@sail home]# docker stats -a
CONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS
0aee6f74b913 brave_rosalind 0.00% 0B / 0B 0.00% 0B / 0B 0B / 0B 0
c3d59f55d600 musing_poincare 0.00% 0B / 0B 0.00% 0B / 0B 0B / 0B 0
569026bc0955 centos03 0.00% 0B / 0B 0.00% 0B / 0B 0B / 0B 0
71a97b830ec5 centos02 0.00% 0B / 0B 0.00% 0B / 0B 0B / 0B 0
96ed3fe3e7f1 centos01 0.00% 524KiB / 1.694GiB 0.03% 0B / 0B 0B / 0B 1
参考
https://www.bilibili.com/video/BV1og4y1q7M4?spm_id_from=333.999.0.0
https://www.bilibili.com/video/BV1kv411q7Qc?spm_id_from=333.999.0.0
版本
CentOS 7.6
Docker 20.10.11
天河有尽身作涯，星海无边前是岸。
