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

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）。

[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

巴特西

Docker 05 常用命令