#!/usr/bin/env bash set -e mkimg="$(basename "$0")" usage() { echo >&2 "usage: $mkimg [-d dir] [-t tag] script [script-args]" echo >&2 " ie: $mkimg -t someuser/debian debootstrap --variant=minbase jessie" echo >&2 " $mkimg -t someuser/ubuntu debootstrap --include=ubuntu-minimal trusty" echo >&2 " $mkimg -t someuser/busybox busybox-static" echo >&2 " $mkimg -t someuser/centos:5 rinse --distribution centos-5" exit 1 } scriptDir="$(dirname "$(readlink -f "$BASH_SOURCE")")/mkimage" optTemp=$(getopt --options '+d:t:h' --longoptions 'dir:,tag:,help' --name "$mkimg" -- "$@") eval set -- "$optTemp" unset optTemp dir= tag= while true; do case "$1" in -d|--dir) dir="$2" ; shift 2 ;; -t|--tag) tag="$2" ; shift 2 ;; -h|--help) usage ;; --) shift ; break ;; esac done script="$1" [ "$script" ] || usage shift if [ ! -x "$scriptDir/$script" ]; then echo >&2 "error: $script does not exist or is not executable" echo >&2 " see $scriptDir for possible scripts" exit 1 fi # don't mistake common scripts like .febootstrap-minimize as image-creators if [[ "$script" == .* ]]; then echo >&2 "error: $script is a script helper, not a script" echo >&2 " see $scriptDir for possible scripts" exit 1 fi delDir= if [ -z "$dir" ]; then dir="$(mktemp -d ${TMPDIR:-/tmp}/docker-mkimage.XXXXXXXXXX)" delDir=1 fi rootfsDir="$dir/rootfs" ( set -x; mkdir -p "$rootfsDir" ) # pass all remaining arguments to $script "$scriptDir/$script" "$rootfsDir" "$@" # Docker mounts tmpfs at /dev and procfs at /proc so we can remove them rm -rf "$rootfsDir/dev" "$rootfsDir/proc" mkdir -p "$rootfsDir/dev" "$rootfsDir/proc" # make sure /etc/resolv.conf has something useful in it mkdir -p "$rootfsDir/etc" cat > "$rootfsDir/etc/resolv.conf" <<'EOF' nameserver 8.8.8.8 nameserver 8.8.4.4 EOF tarFile="$dir/rootfs.tar.xz" touch "$tarFile" ( set -x tar --numeric-owner -caf "$tarFile" -C "$rootfsDir" --transform='s,^./,,' . ) echo >&2 "+ cat > '$dir/Dockerfile'" cat > "$dir/Dockerfile" <<'EOF' FROM scratch ADD rootfs.tar.xz / EOF # if our generated image has a decent shell, let's set a default command for shell in /bin/bash /usr/bin/fish /usr/bin/zsh /bin/sh; do if [ -x "$rootfsDir/$shell" ]; then ( set -x; echo 'CMD ["'"$shell"'"]' >> "$dir/Dockerfile" ) break fi done ( set -x; rm -rf "$rootfsDir" ) if [ "$tag" ]; then ( set -x; docker build -t "$tag" "$dir" ) elif [ "$delDir" ]; then # if we didn't specify a tag and we're going to delete our dir, let's just build an untagged image so that we did _something_ ( set -x; docker build "$dir" ) fi if [ "$delDir" ]; then ( set -x; rm -rf "$dir" ) fi