[mirror_lxc.git] / templates / lxc-oci.in

#!/bin/bash

# Create application containers from OCI images

# Copyright © 2014 Stéphane Graber <stgraber@ubuntu.com>
# Copyright © 2017 Serge Hallyn <serge@hallyn.com>
#
#  This library is free software; you can redistribute it and/or
#  modify it under the terms of the GNU Lesser General Public
#  License as published by the Free Software Foundation; either
#  version 2.1 of the License, or (at your option) any later version.

#  This library is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
#  Lesser General Public License for more details.

#  You should have received a copy of the GNU Lesser General Public
#  License along with this library; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
#  USA

set -eu
# set -x  # debug

# Make sure the usual locations are in PATH
export PATH=$PATH:/usr/sbin:/usr/bin:/sbin:/bin

# Check for required binaries
for bin in skopeo umoci jq; do
    if ! type $bin >/dev/null 2>&1; then
        echo "ERROR: Missing required tool: $bin" 1>&2
        exit 1
    fi
done

# Some useful functions
cleanup() {
    if [ -d "$DOWNLOAD_TEMP" ]; then
        rm -Rf $DOWNLOAD_TEMP
    fi
}

in_userns() {
    [ -e /proc/self/uid_map ] || { echo no; return; }
    while read line; do
        fields=$(echo $line | awk '{ print $1 " " $2 " " $3 }')
        [ "$fields" = "0 0 4294967295" ] && { echo no; return; } || true
        echo $fields | grep -q " 0 1$" && { echo userns-root; return; } || true
    done < /proc/self/uid_map

    [ "$(cat /proc/self/uid_map)" = "$(cat /proc/1/uid_map)" ] && \
        { echo userns-root; return; }
    echo yes
}

getconfigpath() {
	basedir="$1"
	q="$2"

	digest=`cat "${basedir}/index.json" | jq --arg q "$q" '.manifests[] | if .annotations."org.opencontainers.image.ref.name" == $q then .digest else null end' | sed -e 's/"//g'`
	if [ -z "${digest}" ]; then
		echo "$q not found in index.json" >&2
		return
	fi

	# Ok we have the image config digest, now get the config from that,
	d=${digest:7}
	cdigest=`cat "${basedir}/blobs/sha256/${d}" | jq '.config.digest' | sed -e 's/"//g'`
	if [ -z "${cdigest}" ]; then
		echo "container config not found" >&2
		return
	fi

	d2=${cdigest:7}
	echo "${basedir}/blobs/sha256/${d2}"
	return
}

# get entrypoint from oci image.  Use sh if unspecified
getep() {
	if [ "$#" -eq 0 ]; then
		echo "/bin/sh"
		return
	fi

	configpath="$1"

	ep=`cat "${configpath}" | jq -c '.config.Entrypoint' | sed -e 's/^\[//; s/\]$//; s/","/" "/'`
	cmd=`cat "${configpath}" | jq -c '.config.Cmd' | sed -e 's/^\[//; s/\]$//; s/","/" "/'`
	if [ "${ep}" = "null" ]; then
		ep="${cmd}"
		if [ "${ep}" = "null" ]; then
			ep="/bin/sh"
		fi
	elif [ "${cmd}" != "null" ]; then
		ep="${ep} ${cmd}"
	fi

	if [ -z "${ep}" ]; then
		echo "/bin/sh"
		return
	fi
	echo "${ep}"
	return
}

# get environment from oci image.
getenv() {
	if [ "$#" -eq 0 ]; then
		return
	fi

	configpath="$1"

	cat "${configpath}" > /tmp/config
	env=`cat "${configpath}" | jq -c '.config.Env[]'`

	echo "${env}"
	return
}

usage() {
    cat <<EOF
LXC container template for OCI images

Special arguments:
[ -h | --help ]: Print this help message and exit.

Required arguments:
[ -u | --url <url> ]: The OCI image URL

LXC internal arguments (do not pass manually!):
[ --name <name> ]: The container name
[ --path <path> ]: The path to the container
[ --rootfs <rootfs> ]: The path to the container's rootfs
[ --mapped-uid <map> ]: A uid map (user namespaces)
[ --mapped-gid <map> ]: A gid map (user namespaces)

EOF
    return 0
}

options=$(getopt -o u:h -l help,url:,name:,path:,\
rootfs:,mapped-uid:,mapped-gid: -- "$@")

if [ $? -ne 0 ]; then
    usage
    exit 1
fi
eval set -- "$options"

OCI_URL=""
LXC_MAPPED_GID=
LXC_MAPPED_UID=
LXC_NAME=
LXC_PATH=
LXC_ROOTFS=

while :; do
    case "$1" in
        -h|--help)          usage && exit 1;;
        -u|--url)           OCI_URL=$2; shift 2;;
        --name)             LXC_NAME=$2; shift 2;;
        --path)             LXC_PATH=$2; shift 2;;
        --rootfs)           LXC_ROOTFS=$2; shift 2;;
        --mapped-uid)       LXC_MAPPED_UID=$2; shift 2;;
        --mapped-gid)       LXC_MAPPED_GID=$2; shift 2;;
        *)                  break;;
    esac
done

# Check that we have all variables we need
if [ -z "$LXC_NAME" ] || [ -z "$LXC_PATH" ] || [ -z "$LXC_ROOTFS" ]; then
    echo "ERROR: Not running through LXC." 1>&2
    exit 1
fi

if [ -z "$OCI_URL" ]; then
    echo "ERROR: no OCI URL given"
    exit 1
fi

USERNS=$(in_userns)

if [ "$USERNS" != "no" ]; then
    if [ "$USERNS" = "yes" ]; then
        if [ -z "$LXC_MAPPED_UID" ] || [ "$LXC_MAPPED_UID" = "-1" ]; then
            echo "ERROR: In a user namespace without a map." 1>&2
            exit 1
        fi
        DOWNLOAD_MODE="user"
        DOWNLOAD_TARGET="user"
    else
        DOWNLOAD_MODE="user"
        DOWNLOAD_TARGET="system"
    fi
fi

# Trap all exit signals
trap cleanup EXIT HUP INT TERM

if ! type mktemp >/dev/null 2>&1; then
    DOWNLOAD_TEMP=/tmp/lxc-oci.$$
    mkdir -p $DOWNLOAD_TEMP
else
    DOWNLOAD_TEMP=$(mktemp -d)
fi

# Download the image - TODO - cache
skopeo copy "${OCI_URL}" "oci:${DOWNLOAD_TEMP}:latest"

# Unpack the rootfs
echo "Unpacking the rootfs"

umoci_args=("")
if [ -n "$LXC_MAPPED_UID" ] && [ "$LXC_MAPPED_UID" != "-1" ]; then
    umoci_args+=(--rootless)
fi
umoci unpack ${umoci_args[@]} --image "${DOWNLOAD_TEMP}:latest" "${LXC_ROOTFS}.tmp"
rmdir "${LXC_ROOTFS}"
mv "${LXC_ROOTFS}.tmp/rootfs" "${LXC_ROOTFS}"
rm -rf "${LXC_ROOTFS}.tmp"

OCI_CONF_FILE=$(getconfigpath ${DOWNLOAD_TEMP} latest)
LXC_CONF_FILE="${LXC_PATH}/config"
entrypoint=$(getep ${OCI_CONF_FILE})
echo "lxc.execute.cmd = '${entrypoint}'" >> "${LXC_CONF_FILE}"
echo "lxc.mount.auto = proc:mixed sys:mixed cgroup:mixed" >> "${LXC_CONF_FILE}"

environment=$(getenv ${OCI_CONF_FILE})
while read -r line; do
    echo "lxc.environment = ${line}" >> "${LXC_CONF_FILE}"
done <<< "${environment}"

echo "lxc.uts.name = ${LXC_NAME}" >> "${LXC_CONF_FILE}"
# set the hostname
cat <<EOF > ${LXC_ROOTFS}/etc/hostname
${LXC_NAME}
EOF

# set minimal hosts
cat <<EOF > ${LXC_ROOTFS}/etc/hosts
127.0.0.1   localhost
127.0.1.1   ${LXC_NAME}
EOF

if [ -n "$LXC_MAPPED_UID" ] && [ "$LXC_MAPPED_UID" != "-1" ]; then
    chown $LXC_MAPPED_UID $LXC_PATH/config $LXC_PATH/fstab >/dev/null 2>&1 || true
fi
if [ -n "$LXC_MAPPED_GID" ] && [ "$LXC_MAPPED_GID" != "-1" ]; then
    chgrp $LXC_MAPPED_GID $LXC_PATH/config $LXC_PATH/fstab >/dev/null 2>&1 || true
fi

exit 0
Commit	Line	Data
0ef43a5c SH	1	#!/bin/bash
	2
	3	# Create application containers from OCI images
	4
	5	# Copyright © 2014 Stéphane Graber <stgraber@ubuntu.com>
	6	# Copyright © 2017 Serge Hallyn <serge@hallyn.com>
	7	#
	8	# This library is free software; you can redistribute it and/or
	9	# modify it under the terms of the GNU Lesser General Public
	10	# License as published by the Free Software Foundation; either
	11	# version 2.1 of the License, or (at your option) any later version.
	12
	13	# This library is distributed in the hope that it will be useful,
	14	# but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	# Lesser General Public License for more details.
	17
	18	# You should have received a copy of the GNU Lesser General Public
	19	# License along with this library; if not, write to the Free Software
	20	# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
	21	# USA
	22
	23	set -eu
	24	# set -x # debug
	25
	26	# Make sure the usual locations are in PATH
	27	export PATH=$PATH:/usr/sbin:/usr/bin:/sbin:/bin
	28
	29	# Check for required binaries
	30	for bin in skopeo umoci jq; do
	31	if ! type $bin >/dev/null 2>&1; then
	32	echo "ERROR: Missing required tool: $bin" 1>&2
	33	exit 1
	34	fi
	35	done
	36
	37	# Some useful functions
	38	cleanup() {
	39	if [ -d "$DOWNLOAD_TEMP" ]; then
	40	rm -Rf $DOWNLOAD_TEMP
	41	fi
	42	}
	43
	44	in_userns() {
	45	[ -e /proc/self/uid_map ] \|\| { echo no; return; }
	46	while read line; do
	47	fields=$(echo $line \| awk '{ print $1 " " $2 " " $3 }')
	48	[ "$fields" = "0 0 4294967295" ] && { echo no; return; } \|\| true
	49	echo $fields \| grep -q " 0 1$" && { echo userns-root; return; } \|\| true
	50	done < /proc/self/uid_map
	51
	52	[ "$(cat /proc/self/uid_map)" = "$(cat /proc/1/uid_map)" ] && \
	53	{ echo userns-root; return; }
	54	echo yes
	55	}
	56
ce59e4ca	57	getconfigpath() {
0ef43a5c SH	58	basedir="$1"
	59	q="$2"
	60
0ef43a5c SH	61	digest=`cat "${basedir}/index.json" \| jq --arg q "$q" '.manifests[] \| if .annotations."org.opencontainers.image.ref.name" == $q then .digest else null end' \| sed -e 's/"//g'`
	62	if [ -z "${digest}" ]; then
	63	echo "$q not found in index.json" >&2
0ef43a5c SH	64	return
	65	fi
	66
	67	# Ok we have the image config digest, now get the config from that,
	68	d=${digest:7}
	69	cdigest=`cat "${basedir}/blobs/sha256/${d}" \| jq '.config.digest' \| sed -e 's/"//g'`
	70	if [ -z "${cdigest}" ]; then
	71	echo "container config not found" >&2
0ef43a5c SH	72	return
	73	fi
	74
	75	d2=${cdigest:7}
ce59e4ca FA	76	echo "${basedir}/blobs/sha256/${d2}"
	77	return
	78	}
	79
	80	# get entrypoint from oci image. Use sh if unspecified
	81	getep() {
	82	if [ "$#" -eq 0 ]; then
	83	echo "/bin/sh"
	84	return
	85	fi
	86
	87	configpath="$1"
	88
	89	ep=`cat "${configpath}" \| jq -c '.config.Entrypoint' \| sed -e 's/^\[//; s/\]$//; s/","/" "/'`
	90	cmd=`cat "${configpath}" \| jq -c '.config.Cmd' \| sed -e 's/^\[//; s/\]$//; s/","/" "/'`
0ef43a5c SH	91	if [ "${ep}" = "null" ]; then
	92	ep="${cmd}"
	93	if [ "${ep}" = "null" ]; then
	94	ep="/bin/sh"
	95	fi
	96	elif [ "${cmd}" != "null" ]; then
	97	ep="${ep} ${cmd}"
	98	fi
	99
	100	if [ -z "${ep}" ]; then
	101	echo "/bin/sh"
	102	return
	103	fi
	104	echo "${ep}"
	105	return
	106	}
	107
996202e7 FA	108	# get environment from oci image.
	109	getenv() {
	110	if [ "$#" -eq 0 ]; then
	111	return
	112	fi
	113
	114	configpath="$1"
	115
	116	cat "${configpath}" > /tmp/config
	117	env=`cat "${configpath}" \| jq -c '.config.Env[]'`
	118
	119	echo "${env}"
	120	return
	121	}
	122
0ef43a5c SH	123	usage() {
	124	cat <<EOF
	125	LXC container template for OCI images
	126
	127	Special arguments:
	128	[ -h \| --help ]: Print this help message and exit.
	129
	130	Required arguments:
	131	[ -u \| --url <url> ]: The OCI image URL
	132
	133	LXC internal arguments (do not pass manually!):
	134	[ --name <name> ]: The container name
	135	[ --path <path> ]: The path to the container
	136	[ --rootfs <rootfs> ]: The path to the container's rootfs
	137	[ --mapped-uid <map> ]: A uid map (user namespaces)
	138	[ --mapped-gid <map> ]: A gid map (user namespaces)
	139
	140	EOF
	141	return 0
	142	}
	143
960f15bf	144	options=$(getopt -o u:h -l help,url:,name:,path:,\
0ef43a5c SH	145	rootfs:,mapped-uid:,mapped-gid: -- "$@")
	146
	147	if [ $? -ne 0 ]; then
	148	usage
	149	exit 1
	150	fi
	151	eval set -- "$options"
	152
	153	OCI_URL=""
	154	LXC_MAPPED_GID=
	155	LXC_MAPPED_UID=
	156	LXC_NAME=
	157	LXC_PATH=
	158	LXC_ROOTFS=
	159
	160	while :; do
	161	case "$1" in
	162	-h\|--help) usage && exit 1;;
	163	-u\|--url) OCI_URL=$2; shift 2;;
	164	--name) LXC_NAME=$2; shift 2;;
	165	--path) LXC_PATH=$2; shift 2;;
	166	--rootfs) LXC_ROOTFS=$2; shift 2;;
	167	--mapped-uid) LXC_MAPPED_UID=$2; shift 2;;
	168	--mapped-gid) LXC_MAPPED_GID=$2; shift 2;;
	169	*) break;;
	170	esac
	171	done
	172
	173	# Check that we have all variables we need
	174	if [ -z "$LXC_NAME" ] \|\| [ -z "$LXC_PATH" ] \|\| [ -z "$LXC_ROOTFS" ]; then
	175	echo "ERROR: Not running through LXC." 1>&2
	176	exit 1
	177	fi
	178
	179	if [ -z "$OCI_URL" ]; then
	180	echo "ERROR: no OCI URL given"
	181	exit 1
	182	fi
	183
	184	USERNS=$(in_userns)
	185
	186	if [ "$USERNS" != "no" ]; then
	187	if [ "$USERNS" = "yes" ]; then
	188	if [ -z "$LXC_MAPPED_UID" ] \|\| [ "$LXC_MAPPED_UID" = "-1" ]; then
	189	echo "ERROR: In a user namespace without a map." 1>&2
	190	exit 1
	191	fi
	192	DOWNLOAD_MODE="user"
	193	DOWNLOAD_TARGET="user"
	194	else
	195	DOWNLOAD_MODE="user"
	196	DOWNLOAD_TARGET="system"
	197	fi
	198	fi
	199
	200	# Trap all exit signals
	201	trap cleanup EXIT HUP INT TERM
	202
	203	if ! type mktemp >/dev/null 2>&1; then
	204	DOWNLOAD_TEMP=/tmp/lxc-oci.$$
	205	mkdir -p $DOWNLOAD_TEMP
	206	else
	207	DOWNLOAD_TEMP=$(mktemp -d)
	208	fi
209
210	# Download the image - TODO - cache
211	skopeo copy "${OCI_URL}" "oci:${DOWNLOAD_TEMP}:latest"
212
213	# Unpack the rootfs
214	echo "Unpacking the rootfs"
215
51c80577 FA	216	umoci_args=("")
	217	if [ -n "$LXC_MAPPED_UID" ] && [ "$LXC_MAPPED_UID" != "-1" ]; then
	218	umoci_args+=(--rootless)
	219	fi
	220	umoci unpack ${umoci_args[@]} --image "${DOWNLOAD_TEMP}:latest" "${LXC_ROOTFS}.tmp"
0ef43a5c SH	221	rmdir "${LXC_ROOTFS}"
0ef43a5c SH	222	mv "${LXC_ROOTFS}.tmp/rootfs" "${LXC_ROOTFS}"
0ef43a5c SH	223	rm -rf "${LXC_ROOTFS}.tmp"
0ef43a5c SH	224
ce59e4ca	225	OCI_CONF_FILE=$(getconfigpath ${DOWNLOAD_TEMP} latest)
0ef43a5c	226	LXC_CONF_FILE="${LXC_PATH}/config"
ce59e4ca	227	entrypoint=$(getep ${OCI_CONF_FILE})
3dca1af0	228	echo "lxc.execute.cmd = '${entrypoint}'" >> "${LXC_CONF_FILE}"
0ef43a5c SH	229	echo "lxc.mount.auto = proc:mixed sys:mixed cgroup:mixed" >> "${LXC_CONF_FILE}"
0ef43a5c SH	230
996202e7 FA	231	environment=$(getenv ${OCI_CONF_FILE})
	232	while read -r line; do
	233	echo "lxc.environment = ${line}" >> "${LXC_CONF_FILE}"
	234	done <<< "${environment}"
	235
bc2c91ae FA	236	echo "lxc.uts.name = ${LXC_NAME}" >> "${LXC_CONF_FILE}"
	237	# set the hostname
	238	cat <<EOF > ${LXC_ROOTFS}/etc/hostname
	239	${LXC_NAME}
	240	EOF
0ef43a5c	241
b5236550 FA	242	# set minimal hosts
	243	cat <<EOF > ${LXC_ROOTFS}/etc/hosts
	244	127.0.0.1 localhost
	245	127.0.1.1 ${LXC_NAME}
	246	EOF
	247
0ef43a5c SH	248	if [ -n "$LXC_MAPPED_UID" ] && [ "$LXC_MAPPED_UID" != "-1" ]; then
	249	chown $LXC_MAPPED_UID $LXC_PATH/config $LXC_PATH/fstab >/dev/null 2>&1 \|\| true
	250	fi
	251	if [ -n "$LXC_MAPPED_GID" ] && [ "$LXC_MAPPED_GID" != "-1" ]; then
	252	chgrp $LXC_MAPPED_GID $LXC_PATH/config $LXC_PATH/fstab >/dev/null 2>&1 \|\| true
	253	fi
	254
	255	exit 0