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executable file 121 lines (97 sloc) 3.19 KB
#!/usr/bin/env bash
set -e
mkimg="$(basename "$0")"
usage() {
echo >&2 "usage: $mkimg [-d dir] [-t tag] [--compression algo| --no-compression] script [script-args]"
echo >&2 " ie: $mkimg -t someuser/debian debootstrap --variant=minbase jessie"
echo >&2 " $mkimg -t someuser/ubuntu debootstrap --include=ubuntu-minimal --components=main,universe trusty"
echo >&2 " $mkimg -t someuser/busybox busybox-static"
echo >&2 " $mkimg -t someuser/centos:5 rinse --distribution centos-5"
echo >&2 " $mkimg -t someuser/mageia:4 mageia-urpmi --version=4"
echo >&2 " $mkimg -t someuser/mageia:4 mageia-urpmi --version=4 --mirror=http://somemirror/"
exit 1
}
scriptDir="$(dirname "$(readlink -f "$BASH_SOURCE")")/mkimage"
os=
os=$(uname -o)
optTemp=$(getopt --options '+d:t:c:hC' --longoptions 'dir:,tag:,compression:,no-compression,help' --name "$mkimg" -- "$@")
eval set -- "$optTemp"
unset optTemp
dir=
tag=
compression="auto"
while true; do
case "$1" in
-d|--dir) dir="$2" ; shift 2 ;;
-t|--tag) tag="$2" ; shift 2 ;;
--compression) compression="$2" ; shift 2 ;;
--no-compression) compression="none" ; shift 1 ;;
-h|--help) usage ;;
--) shift ; break ;;
esac
done
script="$1"
[ "$script" ] || usage
shift
if [ "$compression" == 'auto' ] || [ -z "$compression" ]
then
compression='xz'
fi
[ "$compression" == 'none' ] && compression=''
if [ ! -x "$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 ${TMPDIR:-/var/tmp}/docker-mkimage.XXXXXXXXXX)"
delDir=1
fi
rootfsDir="$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${compression:+.$compression}"
touch "$tarFile"
(
set -x
tar --numeric-owner --create --auto-compress --file "$tarFile" --directory "$rootfsDir" --transform='s,^./,,' .
)
echo >&2 "+ cat > '$dir/Dockerfile'"
cat > "$dir/Dockerfile" <<EOF
FROM scratch
ADD $(basename "$tarFile") /
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