While doing development and debugging, we might want to look inside an already running container. There are a few utilities, such as nsenter (https://github.com/jpetazzo/nsenter), which allow us to enter the namespace of the container to inspect its state. With the exec option, which was added in Docker 1.3, we can inject a new process inside a running container.
Injecting a new process into a running container
Getting ready
Make sure that the Docker daemon is running on the host and that you can connect through the Docker client. You might also need a running container to inject a process into.
