How to enter a Docker

https://blog.codecentric.de/en/2014/07/enter-docker-container/

nsenter
The nsenter tool is part of the util-linux package since version 2.23. It provides access to the namespace of another process. nsenter requires root privileges to work properly. Unfortunately, util-linux is still at version 2.20 in Ubuntu 14.04.

To install the latest version (2.24) proceed as follows:

cd /tmp curl https://www.kernel.org/pub/linux/utils/util-linux/v2.24/util-linux-2.24.tar.gz | tar -zxf- cd util-linux-2.24 ./configure --without-ncurses make nsenter cp nsenter /usr/local/bin

In order to connect to a container, you have to find out the PID of the first process in the container.

docker inspect --format "{{ .State.Pid }}" <container-id>

With that PID you can connect to the container:

nsenter --target $PID --mount --uts --ipc --net --pid