create-lx-image

#!/usr/bin/env bash
#
# Copyright (c) 2015 Joyent Inc., All rights reserved.
#
# Create an lx-brand image from a given tar file

# shellcheck disable=2154
if [[ -n "$TRACE" ]]; then
  export PS4='[\D{%FT%TZ}] ${BASH_SOURCE}:${LINENO}: ${FUNCNAME[0]:+${FUNCNAME[0]}(): }'
  set -o xtrace
fi

set -euo pipefail
IFS=$'\n\t'

BUILD_DATE=$(date +%Y%m%d)
TARBALL=
KERNEL=
MIN_PLATFORM=
IMAGE_NAME=
DESC=
DOCS=


usage() {
cat <<EOF

Create an lx brand CentOS image from a given tar file

Usage:
  $0 -t <TARBALL> -k <KERNEL> -m <MIN_PLATFORM> -i <IMAGE_NAME> -d <DESC> -u <DOCS>

Example:
  $0 -t /var/tmp/lx-centos-6-20150408.tar.gz -k 2.6.32 -m 20150316T201553Z -i lx-centos-6 -d "CentOS 6.6 64-bit lx-brand image." -u https://docs.joyent.com/images/container-native-linux

OPTIONS:
  -t The full path to the tar archive
  -k The kernel version
  -m The minimum platform required for the image
  -i The name of the image as it would appear in the manifest
  -d The description of the image as it would appear in the manifest
  -u The homepage link of the image as it would appear in the manifest
  -h Show this message

EOF
}

while getopts "ht:k:m:i:d:u:" OPTION
do
	case $OPTION in
		h)
			usage
			exit
			;;
		t)
			TARBALL=${OPTARG}
			;;
		k)
			KERNEL=${OPTARG}
			;;
		m)
			MIN_PLATFORM=${OPTARG}
			;;
		i)
			IMAGE_NAME=${OPTARG}
			;;
		d)
			DESC=${OPTARG}
			;;
		u)
			DOCS=${OPTARG}
			;;
		*)
			usage
			exit 1
			;;
	esac
done

if [[ -z $TARBALL ]]; then
	echo "==> ERROR: the install archive is required"
	usage
	exit 1
fi

if [[ ! -a "$TARBALL" ]]; then
	printf "==> ERROR: %s: file or directory not found\n" "$TARBALL"
	exit 1
fi

if [[ "$(echo "$TARBALL" | cut -c 1)" != "/" ]]; then
	printf "==> Pathname '%s' specified to -t must be absolute\n" "$TARBALL"
	exit 1
fi

if [[ ! -r "$TARBALL" ]]; then
	printf "==> Cannot read file '%s'\n" "$TARBALL"
	exit 1
fi

if [[ ! -f "$TARBALL" ]]; then
	echo "==> ERROR: must be a gzip, bzip2, .Z or uncompressed tar archive"
	exit 1
fi

if [[ -z ${KERNEL} ]]; then
	echo "Error: missing kernel version (-k) value"
	exit 1
fi

if [[ -z ${MIN_PLATFORM} ]]; then
	echo "Error: missing minimum platform (-m) value"
	exit 1
fi

if [[ -z ${IMAGE_NAME} ]]; then
	echo "Error: missing image name (-i) value"
	exit 1
fi

if [[ -z ${DESC} ]]; then
	echo "Error: missing image description (-d) value"
	exit 1
fi

if [[ -z ${DOCS} ]]; then
	DOCS="https://docs.joyent.com/images/container-native-linux"
fi

IUUID=${IMAGE_NAME}-$BUILD_DATE

filetype=$({ LC_ALL=C file "$TARBALL" | awk '{print $2}' ; } 2>/dev/null)

if [[ "$filetype" = "gzip" ]]; then
	gtaropts="-xz"
elif [[ "$filetype" = "bzip2" ]]; then
	gtaropts="-xj"
elif [[ "$filetype" = "compressed" ]]; then
	gtaropts="-xZ"
elif [[ "$filetype" = "USTAR" ]]; then
	gtaropts="-x"
else
	printf "==> ERROR: must be a gzip, bzip2, .Z or uncompressed tar archive"
	exit 1
fi

gtaropts="${gtaropts}f"

zpath="/zones/$IUUID"
zroot="/zones/$IUUID/root"

create_dataset() {
	echo "==> Creating dataset for image creation..."
	zfs create "zones/$IUUID"
	chmod 700 "$zpath"

	mkdir "$zpath/root"
	chmod 755 "$zpath/root"

	mkdir "$zpath/cores"
	chmod 755 "$zpath/cores"

	echo "==> The dataset is zones/$IUUID"
	echo "==>"
}

install_tar() {
	echo "==> Installing the tar archive, this will take a few minutes..."
	if ! (cd "$zroot" && gtar --strip-components=2 "$gtaropts" "$TARBALL"); then
		echo "==> Error: extraction from tar archive failed."
		zfs destroy -r "zones/$IUUID"
	fi
}

modify_image() {
	echo "==> Modifying the image to work in a zone..."

	echo "====> Creating /native directories..."
	mkdir -p "$zroot/native/dev"
	mkdir -p "$zroot/native/etc/default"
	mkdir -p "$zroot/native/etc/svc/volatile"
	mkdir -p "$zroot/native/lib"
	mkdir -p "$zroot/native/proc"
	mkdir -p "$zroot/native/tmp"
	chmod 1777 "$zroot/native/tmp"
	mkdir -p "$zroot/native/usr"
	mkdir -p "$zroot/native/var"
	echo "====> done."

	# Create the /var/ld/ld.config files that will point to /native/lib for our
	# Solaris libraries.

	echo "====> Creating the /var/ld/ld.config file..."
	mkdir "$zroot/var/ld" "$zroot/var/ld/64"

if crle -c "$zroot/var/ld/ld.config" -l /native/lib:/native/usr/lib \
	-s /native/lib/secure:/native/usr/lib/secure ; then
	echo "====> Created \"$zroot/var/ld/ld.config\""
else
	echo "====> Creation of \"$zroot/var/ld/ld.config\" failed!"
	exit 1
fi

if crle -64 -c "$zroot/var/ld/64/ld.config" \
	-l /native/lib/amd64:/native/usr/lib/amd64 \
	-s /native/lib/secure/amd64:/native/usr/lib/secure/amd64 ; then
	echo "====> Created \"$zroot/var/ld/64/ld.config\""
else
	echo "====> Creation of \"$zroot/var/ld/64/ld.config\" failed!"
	exit 1
fi

	echo "====> Setting up fstab..."
cat << EOF > "$zroot/etc/fstab"
none		/			zfs	defaults	1 1
proc		/proc			proc	defaults	0 0
EOF

	echo "==> Image modification complete."
}

create_file() {
	echo "==> Creating image file:"

	echo "====> Creating snapshot..."
	zfs snapshot "zones/$IUUID@final"

	echo "====> Doing a zfs send. This may take a few minutes..."
	zfs send "zones/$IUUID@final" | gzip -9 > "${IMAGE_NAME}-${BUILD_DATE}.zfs.gz"
	echo "====> Done."

	echo "====> Cleaning up..."
	zfs destroy -r "zones/$IUUID"

	echo "==> Image File created!"
	echo "==>"
}

create_manifest() {
	echo "==> Creating manifest file..."
	./create-manifest -f "${IMAGE_NAME}-${BUILD_DATE}.zfs.gz" -k "${KERNEL}" -m "${MIN_PLATFORM}" -n "${IMAGE_NAME}" -o linux -v "${BUILD_DATE}" -d "${DESC}" -h "${DOCS}" > "${IMAGE_NAME}-${BUILD_DATE}.json"
	echo "==> done!"
	echo "==>"
}

show_image_files() {
	echo "*** Image creation complete ***"
	echo "==> Image files:"
	echo "${IMAGE_NAME}-${BUILD_DATE}.zfs.gz"
	echo "${IMAGE_NAME}-${BUILD_DATE}.json"
	echo ""
}

create_dataset
install_tar
modify_image
create_file
create_manifest
show_image_files

exit 0