rktup

#!/usr/bin/env bash

# you may try to configure those variables
RKT_VERSION=1.20.0
RKT_PACKAGE_SIZE=95333129
ACBUILD_VERSION=0.4.0
ACBUILD_PACKAGE_SIZE=11864872
# DESTDIR is supported

## get file size. usage: getsize file.txt
function getsize() {
	stat --printf='%s' "$1"
}

## downloads URl to file OUTPUT 
## download is skipped if file SIZE is supplied and file exists and size matches
function download() {
	URL=$1
	OUTPUT=$2
	SIZE=$3

	if [ -n "$SIZE" -a -f "$OUTPUT" ]; then
		if [ $(getsize "$OUTPUT") == $SIZE ]; then
			echo "$OUTPUT already downloaded, size matched"
			return 0
		else
			echo "$OUTPUT size differs redownloading from $URL..."
		fi
	fi

	mkdir -p $(dirname "$OUTPUT")
	if which curl; then
		curl --location --output "$OUTPUT" "$URL"
	elif which wget; then
		wget "--output-document=$OUTPUT" "$URL"
	else
		echo "unable to download $1 neither wget nor curl found"
		exit 1
	fi

	if [ -n "$SIZE" ]; then
		if [ $(getsize "$OUTPUT") != $SIZE ]; then
			echo "size differs after download, it was unsuccessfull"
			return 1
		fi		
	fi
}



function install-rkt() {
	local CACHE="$CACHE/rkt"
	local URL="https://github.com/coreos/rkt/releases/download/v$RKT_VERSION/rkt-v$RKT_VERSION.tar.gz"
	local DIR="$CACHE/rkt-v$RKT_VERSION"
	local PACKAGE="$DIR.tar.gz"

	echo 'downloading rkt'
	download "$URL" "$PACKAGE" "$RKT_PACKAGE_SIZE" || exit 1

	echo "unpacking rkt..."
	mkdir -p "$DIR"
	tar xzf "$PACKAGE" --directory "$CACHE"
	touch $CACHE/unpack-flag

	echo 'installing rkt...'
	mkdir -p "${DESTDIR}/usr/bin"
	cp "$DIR/rkt" "${DESTDIR}/usr/bin/rkt"
	chmod ugo+x "${DESTDIR}/usr/bin/rkt"

	# images
	IMAGE_DIR="${DESTDIR}/usr/lib/rkt/stage1-images"
	mkdir -p "$IMAGE_DIR"
	for ACI in stage1-coreos.aci stage1-fly.aci stage1-kvm.aci; do
		cp "$DIR/$ACI" "$IMAGE_DIR/$ACI"
	done

	mkdir -p "${DESTDIR}/var/lib/rkt"
	if [ $(id -u) == 0 ]; then
		echo 'configuring system...'
		groupadd rkt || true
		bash "$DIR/scripts/setup-data-dir.sh" "${DESTDIR}/var/lib/rkt"
	fi
	echo rkt installed
}



function install-acbuild() {

	local CACHE="$CACHE/acbuild"
	local URL=https://github.com/appc/acbuild/releases/download/v${ACBUILD_VERSION}/acbuild-v${ACBUILD_VERSION}.tar.gz
	local DIR="${CACHE}/acbuild-v${ACBUILD_VERSION}"
	local PACKAGE="${DIR}.tar.gz"

	echo 'downloading acbuild...'
	download "$URL" "$PACKAGE" "$ACBUILD_PACKAGE_SIZE" || exit 1

	echo 'unpacking acbuild...'
	mkdir -p "$DIR"
	tar xzf "$PACKAGE" --directory "$CACHE"

	echo 'installing acbuild...'
	cp "$DIR/acbuild" "${DESTDIR}/usr/bin/acbuild"
	chmod ugo+x "${DESTDIR}/usr/bin/acbuild"

	echo acbuild installed
}


function install-uninstaller() {
	SCRIPT="$DESTDIR/usr/lib/rkt/uninstall"
	mkdir -p "${DESTDIR}/usr/lib/rkt"
	echo "#!/usr/bin/env bash
	rm -rf /usr/bin/rkt /usr/bin/acbuild /usr/lib/rkt /var/lib/rkt
" > "$SCRIPT"
	chmod ugo+x "$SCRIPT"
	echo "created uninstall script at $SCRIPT"
}


# find temp
test -z "$TEMP" && TEMP="$TMP"
test -z "$TEMP" && TEMP="/tmp"


# cache 
export CACHE="$TEMP/rktup-cache"
mkdir -p "$CACHE" || (
	echo "error creating $CACHE"
	exit 1
)




install-rkt
install-acbuild
install-uninstaller

todo Error: Mounting "/dev/null" on "/opt/stage2/anyorigin/rootfs/dev/null" failed: Permission denied
(possibly selinux issue)

todo find size of downloaded file with
stat -c%s "$OUTPUT"