Forbedrelse:

sudo apt install docker.io
sudo usermod -a -G docker $USER

Terminal 1:

sudo docker run -it ubuntu:16.04 bash
apt update
apt install pdftk

Terminal 2:

sudo docker ps -a
sudo docker commit CONTAINER_ID ubuntu_pdftk

/usr/local/bin/pdftk

#!/bin/sh

docker run --name pdftk-$$ --user $(id -u):$(id -g) \
  -it -v "$PWD:/workdir$PWD" -w "/workdir$PWD" ubuntu_pdftk pdftk "$@"
docker rm pdftk-$$