Script to download all dependencies of a package on Ubuntu

download_deb_files.sh

#!/usr/bin/env bash

# Inspired from https://ostechnix.com/download-packages-dependencies-locally-ubuntu/

# Can be typically run in docker to select the version you want like:
# docker run -it -v $(pwd):/host ubuntu:20.04 bash -c "$(cat ./this_script.sh)"

package_to_install="docker.io"

apt update; apt install -y apt-rdepends lsb-release
# Download all dependencies + the package itself
apt-get download $(apt-rdepends ${package_to_install} | grep -v "^ " | sed 's/debconf-2.0/debconf/g')
ubuntu_version=$(lsb_release -rs)
# Create an archive of these
tar -cvf "${package_to_install}_ubuntu${ubuntu_version}_packages.tar" *.deb
# Get them back to the host
cp *.tar /host/