狂神说-Docker基础-学习笔记-03 日志、元数据、进程的查看

视频链接：https://www.bilibili.com/video/BV1og4y1q7M4?p=1

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）
————————————————————————————————————————————————————————————————————————————
#实际执行结果：
C:\Users\z>docker run -d centos /bin/sh -c "i=0;while i<10;do echo hello;i=i+1;sleep 1;done"
1ba631a037e8087c91ca541e604c12cf5f17d4e5f102b431bd49f50da0beea07

C:\Users\z>docker ps
CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES

C:\Users\z>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:\Users\z>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:\Users\z>docker run -d centos /bin/sh -c "while true;do echo hello;sleep 1;done"
f538ba990f583e68a58a62453fe989f94045d95531881ee2859e51693aff98d4

C:\Users\z>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:\Users\z>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:\Users\z>

2、进程的查看

docker inspect查看元数据

运行示例：

C:\Users\z>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:\Users\z>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:\Users\z>

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:\Users\z>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:\Users\z>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:\Users\z>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:\Users\z>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:\Users\z>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:\Users\z>
# 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:\Users\z>docker attach f538ba990f58
hello
hello
hello
hello

docker cp 将容器中的问卷拷贝到宿主机

C:\Users\z>docker ps
CONTAINER ID   IMAGE     COMMAND       CREATED          STATUS          PORTS     NAMES
1578c133ad4f   centos    "/bin/bash"   31 minutes ago   Up 30 minutes             centos01

C:\Users\z>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:\Users\z>docker cp 1578c133ad4f:usr/helloDocker.txt D:\Users\z\Downloads

C:\Users\z>

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