image: Add script to build image

Add script to build image based on a rootfs directory.

Signed-off-by: Jose Carlos Venegas Munoz <jose.carlos.venegas.munoz@intel.com>

image-builder/image_builder.sh

@@ -0,0 +1,130 @@
+#!/bin/bash
+#
+# Copyright (c) 2017 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+set -e
+if [ -n "$DEBUG" ] ; then
+	set -x
+fi
+
+SCRIPT_NAME="${0##*/}"
+IMAGE="${IMAGE:-kata-containers.img}"
+AGENT_BIN=${AGENT_BIN:-kata-agent}
+
+die()
+{
+	local msg="$*"
+	echo "ERROR: ${msg}" >&2
+	exit 1
+}
+
+OK()
+{
+	local msg="$*"
+	echo "[OK] ${msg}" >&2
+}
+
+info()
+{
+	local msg="$*"
+	echo "INFO: ${msg}"
+}
+
+usage()
+{
+	error="${1:-0}"
+	cat <<EOT
+Usage: ${SCRIPT_NAME} [options] <rootfs-dir>
+	This script will create a Kata Containers image file based on the 
+	<rootfs-dir> directory.
+
+Options:
+	-h Show this help
+	-o path to generate image file ENV: IMAGE
+	-s Image size in MB (default $IMG_SIZE) ENV: IMG_SIZE
+
+Extra environment variables:
+	AGENT_BIN: use it to change the expected agent binary name"
+EOT
+exit "${error}"
+}
+
+while getopts "ho:s:" opt
+do
+	case "$opt" in
+		h)	usage ;;
+		o)	IMAGE="${OPTARG}" ;;
+		s)	IMG_SIZE="${OPTARG}" ;;
+	esac
+done
+
+shift $(( $OPTIND - 1 ))
+
+ROOTFS="$1"
+
+[ -n "${ROOTFS}" ] || usage
+[ -d "${ROOTFS}" ] || die "${ROOTFS} is not a directory"
+# The kata rootfs image expect init and kata-agent to be installed
+init="${ROOTFS_DIR}/sbin/init"
+[ -x "${init}" ] || [ -L ${init} ] || die "/sbin/init is not installed in ${ROOTFS_DIR}"
+OK "init is installed"
+[ -x "${ROOTFS}/bin/${AGENT_BIN}" ] || \
+	die "/bin/${AGENT_BIN} is not installed in ${ROOTFS_DIR}
+	use AGENT_BIN env variable to change the expected agent binary name"
+OK "Agent installed"
+[ "$(id -u)" -eq 0 ] || die "$0: must be run as root"
+
+BLOCK_SIZE=${BLOCK_SIZE:-4096}
+IMG_SIZE=${IMG_SIZE:-80}
+
+info "Creating raw disk with size ${IMG_SIZE}M"
+qemu-img create -q -f raw "${IMAGE}" "${IMG_SIZE}M"
+OK "Image file created"
+
+# Kata runtime expect an image with just one partition
+# The partition is the rootfs content
+
+info "Creating partitions"
+parted "${IMAGE}" --script "mklabel gpt" \
+"mkpart ext4 1M -1M"
+OK "Partitions created"
+
+# Get the loop device bound to the image file (requires /dev mounted in the
+# image build system and root privileges)
+DEVICE=$(losetup -P -f --show "${IMAGE}")
+
+#Refresh partition table
+partprobe "${DEVICE}"
+
+MOUNT_DIR=$(mktemp -d osbuilder-mount-dir.XXXX)
+info "Formating Image using ext4 format"
+mkfs.ext4 -q -F -b "${BLOCK_SIZE}" "${DEVICE}p1"
+OK "Image formated"
+
+info "Mounting root paratition"
+mount "${DEVICE}p1" "${MOUNT_DIR}"
+OK "root paratition mounted"
+
+RESERVED_BLOCKS_PERCENTAGE=3
+info "Set filesystem reserved blocks percentage to ${RESERVED_BLOCKS_PERCENTAGE}%"
+tune2fs -m "${RESERVED_BLOCKS_PERCENTAGE}" "${DEVICE}p1"
+
+#TODO: Calculate disk size based on rootfs
+#FIXME: https://github.com/kata-containers/osbuilder/issues/2
+ROOTFS_SIZE=$(du -B 1MB -s "${ROOTFS}" | awk '{print $1}')
+AVAIL_DISK=$(df -B M --output=avail "${DEVICE}p1" | tail -1)
+AVAIL_DISK=${AVAIL_DISK/M}
+info "Free space root partition ${AVAIL_DISK} MB"
+info "rootfs size ${ROOTFS_SIZE} MB"
+info "Copying content from rootfs to root partition"
+cp -a "${ROOTFS}"/* ${MOUNT_DIR}
+OK "rootfs copied"
+
+# Cleanup
+sync
+umount -l ${MOUNT_DIR}
+fsck -D -y "${DEVICE}p1"
+losetup -d "${DEVICE}"
+info "Image created"