Question

如果我使用docker container run ubuntu直接从Ubuntu映像运行容器，则可以使用docker start <CONTAINER ID>轻松地重新启动它。但是，我使用docker run <ID IMAGE>使用图像运行容器，一旦退出伪终端，它将完全丢失。

我注意到，每次尝试重新启动状态时，状态都会更新，这意味着主进程开始并立即停止。有想法吗？

portaivan@training-vm:~$ docker image ls -a
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
ubuntu              latest              d70eaf7277ea        8 days ago          72.9MB
portaivan@training-vm:~$ docker container ls -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                      PORTS               NAMES
4004895feff9        d70eaf7277ea        "/bin/bash"         3 hours ago         Exited (0) 3 hours ago                          heuristic_lovelace
3b1b521d62aa        ubuntu              "/bin/bash"         3 hours ago         Exited (0) 23 seconds ago                       sleepy_pike
portaivan@training-vm:~$ docker start 3b1b521d62aa
3b1b521d62aa
portaivan@training-vm:~$ docker container ls -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                   PORTS               NAMES
4004895feff9        d70eaf7277ea        "/bin/bash"         3 hours ago         Exited (0) 3 hours ago                       heuristic_lovelace
3b1b521d62aa        ubuntu              "/bin/bash"         3 hours ago         Up 2 seconds                                 sleepy_pike
portaivan@training-vm:~$ docker container start 4004895feff9
4004895feff9
portaivan@training-vm:~$ docker container ls -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                     PORTS               NAMES
4004895feff9        d70eaf7277ea        "/bin/bash"         3 hours ago         Exited (0) 2 seconds ago                       heuristic_lovelace
3b1b521d62aa        ubuntu              "/bin/bash"         3 hours ago         Up 17 seconds                                  sleepy_pike
portaivan@training-vm:~$ docker container start -i 4004895feff9
portaivan@training-vm:~$ docker container ls -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                     PORTS               NAMES
4004895feff9        d70eaf7277ea        "/bin/bash"         3 hours ago         Exited (0) 2 seconds ago                       heuristic_lovelace
3b1b521d62aa        ubuntu              "/bin/bash"         3 hours ago         Up 28 seconds                                  sleepy_pike

Answer 1

Docker容器在命令运行时仍然存在。
您的命令是"/bin/bash"。

那是

伪终端

因此，当您关闭终端命令（又称容器入口点）时，容器停止。

编辑1.详细说明

如果运行不带-it参数的容器，则会启动bash而不创建会话（pseudo-tty）。

例如，您可以运行：

bash -c "echo 'blabla'"

bash仅运行echo命令并结束进程。
因此，这是容器未退出的两个原因：

如果您跑步

docker container run -t --name u_container ubuntu

您将无法在容器内输入任何命令。由于未附加STDIN。但！您可以通过-t参数创建伪tty，而无需退出即可启动docker容器。

仅使用-i个参数bash时，不要创建tty并希望尽快死亡。但！ docker保持容器运行，并尝试无限传递输入，即使您未附加到容器（请参阅帮助）。尽管我们可以停止bash插入exit。

-i, --interactive Keep STDIN open even if not attached

所以，简单的解释：这取决于您如何运行shell。作为循环和侦听伪终端或仅作为命令解释器。您可以将其与python进行比较。
如果运行python，它将是python shell。如果您运行python /script/script.py，则python只需执行script.py并停止。

Answer 2

几个小时后，我明白了！问题是STDIN在容器运行时关闭。我使用选项-i运行了容器1和容器2。我运行了没有选项-i的Container 3。如您在下图中所看到的，我能够启动Container 1和Container 2，但不能启动Container 3。

====原因！ ====

每个进程都有三个数据流（STDIN / STDOUT / STDERR）。当容器中正在运行进程时，默认情况下，终端将与容器中正在运行的进程的STDOUT流连接。因此，在终端中运行docker run命令时，所有输出流都是可见的。但是，如果要向容器中正在运行的进程提供输入，则必须连接进程的STDIN通道，默认情况下这不是默认操作，而是通过docker run -i命令完成的。

portaivan@training-vm:~$ docker image ls -a
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
portaivan@training-vm:~$ docker container ls -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
portaivan@training-vm:~$ docker container run -it --name container01 ubuntu
Unable to find image 'ubuntu:latest' locally
latest: Pulling from library/ubuntu
6a5697faee43: Pull complete
ba13d3bc422b: Pull complete
a254829d9e55: Pull complete
Digest: sha256:fff16eea1a8ae92867721d90c59a75652ea66d29c05294e6e2f898704bdb8cf1
Status: Downloaded newer image for ubuntu:latest
root@03b44b790cfa:/# ls
bin  boot  dev  etc  home  lib  lib32  lib64  libx32  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var
root@03b44b790cfa:/# exit
exit
portaivan@training-vm:~$ docker container ls -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                     PORTS               NAMES
03b44b790cfa        ubuntu              "/bin/bash"         14 seconds ago      Exited (0) 5 seconds ago                       container01
portaivan@training-vm:~$ docker container start 03b44b790cfa
03b44b790cfa
portaivan@training-vm:~$ docker container ls -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
03b44b790cfa        ubuntu              "/bin/bash"         28 seconds ago      Up 2 seconds                            container01
portaivan@training-vm:~$ docker image ls -a
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
ubuntu              latest              d70eaf7277ea        8 days ago          72.9MB
portaivan@training-vm:~$ docker container run -it --name container02 d70eaf7277ea
root@e6123c0bbe81:/# ls
bin  boot  dev  etc  home  lib  lib32  lib64  libx32  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var
root@e6123c0bbe81:/# exit
exit
portaivan@training-vm:~$ docker container ls -a
CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS                     PORTS               NAMES
e6123c0bbe81        d70eaf7277ea        "/bin/bash"         10 seconds ago       Exited (0) 3 seconds ago                       container02
03b44b790cfa        ubuntu              "/bin/bash"         About a minute ago   Up About a minute                              container01
portaivan@training-vm:~$ docker container start e6123c0bbe81
e6123c0bbe81
portaivan@training-vm:~$ docker container ls -a
CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
e6123c0bbe81        d70eaf7277ea        "/bin/bash"         22 seconds ago       Up 2 seconds                            container02
03b44b790cfa        ubuntu              "/bin/bash"         About a minute ago   Up About a minute                       container01
portaivan@training-vm:~$ docker container run --name container03 d70eaf7277ea
portaivan@training-vm:~$ docker container ls -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                     PORTS               NAMES
7adbb0089b56        d70eaf7277ea        "/bin/bash"         3 seconds ago       Exited (0) 2 seconds ago                       container03
e6123c0bbe81        d70eaf7277ea        "/bin/bash"         2 minutes ago       Up About a minute                              container02
03b44b790cfa        ubuntu              "/bin/bash"         3 minutes ago       Up 2 minutes                                   container01
portaivan@training-vm:~$ docker container start 7adbb0089b56
7adbb0089b56
portaivan@training-vm:~$ docker container ls -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                     PORTS               NAMES
7adbb0089b56        d70eaf7277ea        "/bin/bash"         15 seconds ago      Exited (0) 2 seconds ago                       container03
e6123c0bbe81        d70eaf7277ea        "/bin/bash"         2 minutes ago       Up About a minute                              container02
03b44b790cfa        ubuntu              "/bin/bash"         3 minutes ago       Up 3 minutes                                   container01
portaivan@training-vm:~$

参考

https://docs-stage.docker.com/engine/reference/commandline/container_run/ https://www.howtogeek.com/435903/what-are-stdin-stdout-and-stderr-on-linux/

Docker容器不以ubuntu映像开头（docker start）

2 个答案: