Create a temporary Alpine chroo

alpine-chroot.sh

#!/bin/sh

# Create and launch an alpine chroot

# If /tmp is not tmpfs, change this to /dev/shm
rootfs=/tmp/alpine
set -eu
if ! [ -f $rootfs/etc/resolv.conf ]; then
  if ! [ -f ~/Downloads/alpine.tar.gz ]; then
    curl -Lf -o ~/Downloads/alpine.tar.gz http://dl-cdn.alpinelinux.org/alpine/v3.11/releases/x86_64/alpine-minirootfs-3.11.6-x86_64.tar.gz
  fi
  mkdir -p $rootfs
  sudo tar -C $rootfs -xf ~/Downloads/alpine.tar.gz
  if ! [ -d $rootfs/dev/stdout ]; then
    echo dev proc run sys | xargs -d' ' -I% sudo mount /%/ $rootfs/%/ --bind
  fi
  sudo cp -a /etc/resolv.conf $rootfs/etc/.
fi
sudo chroot $rootfs /bin/sh -i