狂神说-Docker基础-学习笔记-03 日志、元数据、进程的查看
1、docker logs查看日志
要查看日志的前提是 容器中有进程运行过
docker logs -f -t --tail n 容器ID #此处 n 表示首次打印要查看的日志数量 该命令在打印了 n 条日志后 只要还有日志产生 仍会 继续打印日志
-t # 显示时间戳
-f # 对显示的内容格式化（t、f 参数 可以一起写作 -tf 即可 先后次序不影响输出效果）
--tail number #首次输出的 日志条数
docker logs -tf 容器ID # 输出当前容器所有日志
#示例
# 此处 后台启动 centOS 镜像 作为容器 并进入 /bin/sh 运行一段shell脚本 每隔一秒输出 一个 hello 字符串(确保有进程在运行，一边查看日志)
docker run -d centos /bin/sh -c "while true;do echo hello;sleep 1;done"
docker logs -f -t --tail 10 刚刚运行的容器ID
# 这里1的输出效果是 先输出10条日志，然后每隔一秒再输出一条日志（由于是 while true循环，只能ctrl+C结束该命令）
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#实际执行结果：
C:Usersz>docker run -d centos /bin/sh -c "i=0;while i<10;do echo hello;i=i+1;sleep 1;done"
1ba631a037e8087c91ca541e604c12cf5f17d4e5f102b431bd49f50da0beea07
C:Usersz>docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
C:Usersz>docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
1ba631a037e8 centos "/bin/sh -c 'i=0;whi…" 14 seconds ago Exited (0) 12 seconds ago distracted_pare
C:Usersz>docker logs -ft 1ba631a037e8
2021-11-14T04:53:45.756136200Z /bin/sh: 10: No such file or directory
# 由于写的shell脚本不正确，导致后台容器没有运行进程被杀死了，最后只输出了一个错误信息日志（按照设想如果shell脚本正确，会输出10次hello 然后容器停止运行）
#还是执行一下while true 查看结果吧
C:Usersz>docker run -d centos /bin/sh -c "while true;do echo hello;sleep 1;done"
f538ba990f583e68a58a62453fe989f94045d95531881ee2859e51693aff98d4
C:Usersz>docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
f538ba990f58 centos "/bin/sh -c 'while t…" 7 seconds ago Up 6 seconds recursing_tu
C:Usersz>docker logs -ft --tail 10 f538ba990f58
2021-11-14T04:55:56.337365700Z hello
2021-11-14T04:55:57.339553800Z hello
2021-11-14T04:55:58.341160600Z hello
2021-11-14T04:55:59.343652000Z hello
2021-11-14T04:56:00.345573400Z hello
2021-11-14T04:56:01.347140900Z hello
2021-11-14T04:56:02.348679700Z hello
2021-11-14T04:56:03.350375700Z hello
2021-11-14T04:56:04.352198600Z hello
2021-11-14T04:56:05.353991500Z hello
2021-11-14T04:56:06.356389100Z hello
2021-11-14T04:56:07.358056900Z hello
2021-11-14T04:56:08.359753000Z hello
2021-11-14T04:56:09.361280300Z hello
2021-11-14T04:56:10.363219600Z hello
2021-11-14T04:56:11.364954700Z hello
2021-11-14T04:56:12.366588400Z hello
^C
C:Usersz>
2、进程的查看
docker inspect查看元数据
运行示例：
C:Usersz>docker inspect --help
Usage: docker inspect [OPTIONS] NAME|ID [NAME|ID...]
Return low-level information on Docker objects
Options:
-f, --format string Format the output using the given Go template
-s, --size Display total file sizes if the type is container
--type string Return JSON for specified type
C:Usersz>docker inspect 57134526c81c
[
{
"Id": "57134526c81c45ba5b9203e1717728d2e36d611cb3d031371cc36f3d0c736c1d",
"Created": "2021-11-13T16:11:31.5861229Z",
"Path": "/bin/sh",
"Args": [
"-c",
"while true;do echo zhangzhangzhang;sleep 1;done"
],
"State": {
"Status": "running",
"Running": true,
"Paused": false,
"Restarting": false,
"OOMKilled": false,
"Dead": false,
"Pid": 2534,
"ExitCode": 0,
"Error": "",
"StartedAt": "2021-11-13T16:11:32.0996725Z",
"FinishedAt": "0001-01-01T00:00:00Z"
},
"——————————————————————————此处省略 100 lines——————————————————————————————"
"Cmd": [
"/bin/sh",
"-c",
"while true;do echo zhangzhangzhang;sleep 1;done"
]
}
}
}
}
]
C:Usersz>
进入正在运行的容器
docker exec 容器ID # 进入容器后重新开启一个终端，可以在里面进行一些配置和操作
docker attach 容器ID # 直接进入容器正在执行的终端，不会启动新的终端
运行示例：
C:Usersz>docker exec --help
Usage: docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
Run a command in a running container
Options:
-d, --detach Detached mode: run command in the background
--detach-keys string Override the key sequence for detaching a
container
-e, --env list Set environment variables
--env-file list Read in a file of environment variables
-i, --interactive Keep STDIN open even if not attached
--privileged Give extended privileges to the command
-t, --tty Allocate a pseudo-TTY
-u, --user string Username or UID (format:
<name|uid>[:<group|gid>])
-w, --workdir string Working directory inside the container
C:Usersz>docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
57134526c81c centos "/bin/sh -c 'while t…" 14 minutes ago Up 14 minutes centos03
1578c133ad4f centos "/bin/bash" 21 minutes ago Up 21 minutes centos01
C:Usersz>docker exec -it 57134526c81c
"docker exec" requires at least 2 arguments.
See 'docker exec --help'.
Usage: docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
Run a command in a running container
C:Usersz>docker exec -it 57134526c81c /bin/bash # 以交互方式 进入 centos 容器的 bash终端
[root@57134526c81c /]# ls
bin dev etc home lib lib64 lost+found media mnt opt proc root run sbin srv sys tmp usr var
[root@57134526c81c /]# ps -ef
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 16:11 ? 00:00:00 /bin/sh -c while true;do echo zhangzhangzhang;sleep 1;done
root 921 0 0 16:26 pts/0 00:00:00 /bin/bash
root 958 1 0 16:27 ? 00:00:00 /usr/bin/coreutils --coreutils-prog-shebang=sleep /usr/bin/sleep 1
root 959 921 0 16:27 pts/0 00:00:00 ps -ef
[root@57134526c81c /]#
C:Usersz>docker attach 1578c133ad4f
[root@1578c133ad4f /]# ls
bin dev etc home lib lib64 lost+found media mnt opt proc root run sbin srv sys tmp usr var
[root@1578c133ad4f /]# docker
bash: docker: command not found
[root@1578c133ad4f /]# ps -ef
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 16:04 pts/0 00:00:00 /bin/bash
root 18 1 0 16:33 pts/0 00:00:00 ps -ef
[root@1578c133ad4f /]#
C:Usersz>
# 如果以docker attach 的方式进入 上面正在运行 while true 进程的 容器 就会看到这样的输出，而且 由于是 while true 只能以关闭 终端的方式强制退出该容器
C:Usersz>docker attach f538ba990f58
hello
hello
hello
hello
docker cp 将容器中的问卷拷贝到宿主机
C:Usersz>docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
1578c133ad4f centos "/bin/bash" 31 minutes ago Up 30 minutes centos01
C:Usersz>docker attach 1578c133ad4f
[root@1578c133ad4f /]# ls
bin dev etc home lib lib64 lost+found media mnt opt proc root run sbin srv sys tmp usr var
[root@1578c133ad4f /]# cd usr
[root@1578c133ad4f usr]# touch helloDocker.txt
[root@1578c133ad4f usr]# ls
bin games helloDocker.txt include lib lib64 libexec local sbin share src tmp
[root@1578c133ad4f usr]# exit
exit
C:Usersz>docker cp 1578c133ad4f:usr/helloDocker.txt D:UserszDownloads
C:Usersz>
拷贝是一个手动过程，后面的学习中使用 -v 卷的技术 可以实现将容器的文件夹同步到宿主机文件夹