Wrapper for nsinit and nsenter for easily accessing running Docker containers

docker-enter

#! /bin/bash

# Enter a running Docker container using either nsinit(preferred) or nsenter
# You can specify one or the other if desired.
# See
# http://blog.docker.com/2014/06/why-you-dont-need-to-run-sshd-in-docker/
# https://github.com/jpetazzo/nsenter
# https://gist.github.com/ubergarm/ed42ebbea293350c30a6 for compiling nsinit

[[ -n "$1" ]] || { echo "Usage: `basename $0` <container ID or name> [nsinit|nsenter]. Defaults to nsinit if available."; exit 0; }

[[ -n "$2" ]] && cmd=$2 || cmd=nsinit
command -v $cmd >/dev/null 2>&1 || cmd=nsenter
command -v $cmd >/dev/null 2>&1 || { echo "$cmd must be installed"; exit 1; }

if [ $(id -ru) -ne 0 ]; then
  echo "You have to be root."
  exit 1
fi

if [[ $cmd == "nsinit" ]]; then
	# libcontainer driver method:
	echo "Using nsinit..."
	FULL_ID=$(docker inspect --format='{{.Id}}' $1)
	bash -c "cd /var/lib/docker/execdriver/native/$FULL_ID && nsinit exec bash"
	exit 0
elif [[ $cmd == "nsenter" ]]; then
	echo "Using nsenter..."
	export PATH=$PATH:/bin:/sbin
	PID=$(docker inspect --format {{.State.Pid}} "$1")
	nsenter --target $PID --mount --uts --ipc --net --pid
	exit 0
fi

docker-enter.completion

_docker_enter() {
  local cur prev words cword
  _get_comp_words_by_ref -n : cur prev words cword
  __docker_containers_running
}

. /usr/share/bash-completion/completions/docker
complete -F _docker_enter docker-enter