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This article introduces the knowledge of "common commands for docker to enter the container". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Use docker attach to enter

Docker provides the attach command to enter the Docker container. We create a guarded Docker container and then use the docker attach command to enter the container.

$sudo docker run-itd ubuntu:14.04 / bin/bash

Then we use docker ps to see the container information, and then we use docker attach to enter the container

$sudo docker attach 44fc0f0582d9

You can see that we have entered the container.

But there is a problem with using this command. When multiple windows enter the container at the same time using this command, all windows are displayed synchronously. If one window is blocked, the other windows can no longer operate. Therefore, the docker attach command is not suitable for production environments and can be used when developing your own applications.

Use nsenter to enter the Docker container

Use nsenter to enter the Docker container. After knowing what nsenter is, the system installs the nsenter we need into the host by default. The specific installation commands are as follows:

$wget https://www.kernel.org/pub/linux/utils/util-linux/v2.24/util-linux-2.24.tar.gz$ tar-xzvf util-linux-2.24.tar.gz$ cd util-linux-2.24/$. / configure-- without-ncurses$ make nsenter$ sudo cp nsenter / usr/local/bin

After you have installed nsenter, you can check the use of this command. Nsenter can access the namespace of another process. So to connect to a container, we also need to get the PID of the first process of the container. You can use the docker inspect command to get the PID.

$sudo docker inspect-help

The inspect command can display information about an image or container at a hierarchical level. For example, we currently have a running container, and we can use docker inspect to view the details of the container.

$sudo docker inspect 44fc0f0582d9

If you want to display the first PID of the container, you can use the following ways

$sudo docker inspect-f {{.State.Pid}} 44fc0f0582d9

After getting the process PID, we can use the nsenter command to access the container.

Sudo nsenter-- target 3326-- mount-- uts-- ipc-- net-- pid$ sudo nsenter-- target 3326-- mount-- uts-- ipc-- net-- pid

3326 of them are the PID of the process just obtained.

Use docker exec to enter

Docker also provides a new command exec to enter the container after version 1.3.x, which is relatively simple.

$sudo docker exec-help

Next we use this command to enter a container that is already running

This is the end of the $sudo docker ps$ sudo docker exec-it 775c7c9ee1e1 / bin/bash "common commands for docker to enter the container". Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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