Docker 05 常用命令
阅读原文时间:2023年07月08日阅读:4

参考源

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

本文章基于 Docker 20.10.11


启动 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

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

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

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。

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。

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

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)。

    [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

    [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