#!/bin/sh # Client script for LXC container images. # # Copyright © 2014 Stéphane Graber # # 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 LOCALSTATEDIR="@LOCALSTATEDIR@" LXC_HOOK_DIR="@LXCHOOKDIR@" LXC_TEMPLATE_CONFIG="@LXCTEMPLATECONFIG@" # Defaults DOWNLOAD_ARCH= DOWNLOAD_BUILD= DOWNLOAD_COMPAT_LEVEL=5 DOWNLOAD_DIST= DOWNLOAD_FLUSH_CACHE="false" DOWNLOAD_FORCE_CACHE="false" DOWNLOAD_INTERACTIVE="false" DOWNLOAD_KEYID="0xE7FB0CAEC8173D669066514CBAEFF88C22F6E216" DOWNLOAD_LIST_IMAGES="false" DOWNLOAD_MODE="system" DOWNLOAD_READY_GPG="false" DOWNLOAD_RELEASE= DOWNLOAD_SERVER="images.linuxcontainers.org" DOWNLOAD_SHOW_GPG_WARNING="true" DOWNLOAD_SHOW_HTTP_WARNING="true" DOWNLOAD_TARGET="system" DOWNLOAD_URL= DOWNLOAD_USE_CACHE="false" DOWNLOAD_VALIDATE="true" DOWNLOAD_VARIANT="default" DOWNLOAD_TEMP= LXC_MAPPED_GID= LXC_MAPPED_UID= LXC_NAME= LXC_PATH= LXC_ROOTFS= if [ -z "${DOWNLOAD_KEYSERVER:-}" ]; then DOWNLOAD_KEYSERVER="hkp://pool.sks-keyservers.net" # Deal with GPG over http proxy if [ -n "${http_proxy:-}" ]; then DOWNLOAD_KEYSERVER="hkp://p80.pool.sks-keyservers.net:80" DOWNLOAD_GPG_PROXY="--keyserver-options http-proxy=\"${http_proxy}\"" fi fi # Make sure the usual locations are in PATH export PATH=$PATH:/usr/sbin:/usr/bin:/sbin:/bin # Some useful functions cleanup() { if [ -d "${DOWNLOAD_TEMP}" ]; then rm -Rf "${DOWNLOAD_TEMP}" fi } wget_wrapper() { for _ in $(seq 3); do if wget "$@"; then return 0 fi done return 1 } download_file() { if ! wget_wrapper -T 30 -q "https://${DOWNLOAD_SERVER}/$1" -O "$2" >/dev/null 2>&1; then if ! wget_wrapper -T 30 -q "http://${DOWNLOAD_SERVER}/$1" -O "$2" >/dev/null 2>&1; then if [ "$3" = "noexit" ]; then return 1 else echo "ERROR: Failed to download http://${DOWNLOAD_SERVER}/$1" 1>&2 exit 1 fi elif [ "${DOWNLOAD_SHOW_HTTP_WARNING}" = "true" ]; then DOWNLOAD_SHOW_HTTP_WARNING="false" echo "WARNING: Failed to download the file over HTTPs" 1>&2 echo " The file was instead download over HTTP " 1>&2 echo "A server replay attack may be possible!" 1>&2 fi fi } download_sig() { if ! download_file "$1" "$2" noexit; then if [ "${DOWNLOAD_VALIDATE}" = "true" ]; then if [ "$3" = "normal" ]; then echo "ERROR: Failed to download http://${DOWNLOAD_SERVER}/$1" 1>&2 exit 1 else return 1 fi else return 0 fi fi } gpg_setup() { if [ "${DOWNLOAD_VALIDATE}" = "false" ]; then return fi if [ "${DOWNLOAD_READY_GPG}" = "true" ]; then return fi echo "Setting up the GPG keyring" mkdir -p "${DOWNLOAD_TEMP}/gpg" chmod 700 "${DOWNLOAD_TEMP}/gpg" export GNUPGHOME="${DOWNLOAD_TEMP}/gpg" success= for _ in $(seq 3); do if $(gpg --keyserver "${DOWNLOAD_KEYSERVER}" ${DOWNLOAD_GPG_PROXY:-} \ --recv-keys "${DOWNLOAD_KEYID}" >/dev/null 2>&1); then success=1 break fi break done if [ -z "${success}" ]; then echo "ERROR: Unable to fetch GPG key from keyserver" exit 1 fi DOWNLOAD_READY_GPG="true" } gpg_validate() { if [ "${DOWNLOAD_VALIDATE}" = "false" ]; then if [ "${DOWNLOAD_SHOW_GPG_WARNING}" = "true" ]; then echo "WARNING: Running without gpg validation!" 1>&2 fi DOWNLOAD_SHOW_GPG_WARNING="false" return 0 fi if ! gpg --verify "$1" >/dev/null 2>&1; then echo "ERROR: Invalid signature for $1" 1>&2 exit 1 fi } in_userns() { [ -e /proc/self/uid_map ] || { echo no; return; } while read -r line; do fields="$(echo "$line" | awk '{ print $1 " " $2 " " $3 }')" if [ "${fields}" = "0 0 4294967295" ]; then echo no; return; fi if echo "${fields}" | grep -q " 0 1$"; then echo userns-root; return; fi done < /proc/self/uid_map [ "$(cat /proc/self/uid_map)" = "$(cat /proc/1/uid_map)" ] && { echo userns-root; return; } echo yes } relevant_file() { FILE_PATH="${LXC_CACHE_PATH}/$1" if [ -e "${FILE_PATH}-${DOWNLOAD_MODE}" ]; then FILE_PATH="${FILE_PATH}-${DOWNLOAD_MODE}" fi if [ -e "${FILE_PATH}.${DOWNLOAD_COMPAT_LEVEL}" ]; then FILE_PATH="${FILE_PATH}.${DOWNLOAD_COMPAT_LEVEL}" fi echo "${FILE_PATH}" } usage() { cat < ]: The name of the distribution [ -r | --release ]: Release name/version [ -a | --arch ]: Architecture of the container Optional arguments: [ --variant ]: Variant of the image (default: "default") [ --server ]: Image server (default: "images.linuxcontainers.org") [ --keyid ]: GPG keyid (default: 0x...) [ --keyserver ]: GPG keyserver to use. Environment variable: DOWNLOAD_KEYSERVER [ --no-validate ]: Disable GPG validation (not recommended) [ --flush-cache ]: Flush the local copy (if present) [ --force-cache ]: Force the use of the local copy even if expired LXC internal arguments (do not pass manually!): [ --name ]: The container name [ --path ]: The path to the container [ --rootfs ]: The path to the container's rootfs [ --mapped-uid ]: A uid map (user namespaces) [ --mapped-gid ]: A gid map (user namespaces) Environment Variables: DOWNLOAD_KEYSERVER : The URL of the key server to use, instead of the default. Can be further overridden by using optional argument --keyserver EOF return 0 } if ! options=$(getopt -o d:r:a:hl -l dist:,release:,arch:,help,list,variant:,\ server:,keyid:,keyserver:,no-validate,flush-cache,force-cache,name:,path:,\ rootfs:,mapped-uid:,mapped-gid: -- "$@"); then usage exit 1 fi eval set -- "$options" while :; do case "$1" in -h|--help) usage && exit 1;; -l|--list) DOWNLOAD_LIST_IMAGES="true"; shift 1;; -d|--dist) DOWNLOAD_DIST="$2"; shift 2;; -r|--release) DOWNLOAD_RELEASE="$2"; shift 2;; -a|--arch) DOWNLOAD_ARCH="$2"; shift 2;; --variant) DOWNLOAD_VARIANT="$2"; shift 2;; --server) DOWNLOAD_SERVER="$2"; shift 2;; --keyid) DOWNLOAD_KEYID="$2"; shift 2;; --keyserver) DOWNLOAD_KEYSERVER="$2"; shift 2;; --no-validate) DOWNLOAD_VALIDATE="false"; shift 1;; --flush-cache) DOWNLOAD_FLUSH_CACHE="true"; shift 1;; --force-cache) DOWNLOAD_FORCE_CACHE="true"; shift 1;; --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="$2"; shift 2;; *) break;; esac done # Check for required binaries for bin in tar xz wget; do if ! command -V "${bin}" >/dev/null 2>&1; then echo "ERROR: Missing required tool: ${bin}" 1>&2 exit 1 fi done # Check for GPG if [ "${DOWNLOAD_VALIDATE}" = "true" ]; then if ! command -V gpg >/dev/null 2>&1; then echo "ERROR: Missing recommended tool: gpg" 1>&2 echo "You can workaround this by using --no-validate" 1>&2 exit 1 fi fi # Check that we have all variables we need if [ -z "${LXC_NAME}" ] || [ -z "${LXC_PATH}" ] || [ -z "${LXC_ROOTFS}" ]; then if [ "${DOWNLOAD_LIST_IMAGES}" != "true" ]; then echo "ERROR: Please pass the name, path, and rootfs for the container" 1>&2 exit 1 fi fi USERNS="$(in_userns)" if [ "${USERNS}" != "no" ]; then if [ "${USERNS}" = "yes" ]; then if [ -z "${LXC_MAPPED_UID}" ] || [ "${LXC_MAPPED_UID}" = "-1" ]; then echo "ERROR: In a user namespace without a map" 1>&2 exit 1 fi DOWNLOAD_MODE="user" DOWNLOAD_TARGET="user" else DOWNLOAD_MODE="user" DOWNLOAD_TARGET="system" fi fi if [ -z "${DOWNLOAD_DIST}" ] || [ -z "${DOWNLOAD_RELEASE}" ] || [ -z "${DOWNLOAD_ARCH}" ]; then DOWNLOAD_INTERACTIVE="true" fi # Trap all exit signals trap cleanup EXIT HUP INT TERM # /tmp may be mounted in tmpfs or noexec if mountpoint -q /tmp; then DOWNLOAD_TEMP="${LXC_PATH}" fi if ! command -V mktemp >/dev/null 2>&1; then DOWNLOAD_TEMP="${DOWNLOAD_TEMP}/tmp/lxc-download.$$" elif [ -n "${DOWNLOAD_TEMP}" ]; then mkdir -p "${DOWNLOAD_TEMP}" DOWNLOAD_TEMP="$(mktemp -p ${DOWNLOAD_TEMP} -d)" else DOWNLOAD_TEMP="${DOWNLOAD_TEMP}$(mktemp -d)" fi # Simply list images if [ "${DOWNLOAD_LIST_IMAGES}" = "true" ] || [ "${DOWNLOAD_INTERACTIVE}" = "true" ]; then # Initialize GPG gpg_setup # Grab the index DOWNLOAD_INDEX_PATH="/meta/1.0/index-${DOWNLOAD_MODE}" echo "Downloading the image index" if ! download_file "${DOWNLOAD_INDEX_PATH}.${DOWNLOAD_COMPAT_LEVEL}" "${DOWNLOAD_TEMP}/index" noexit || ! download_sig "${DOWNLOAD_INDEX_PATH}.${DOWNLOAD_COMPAT_LEVEL}.asc" "${DOWNLOAD_TEMP}/index.asc" noexit; then download_file "${DOWNLOAD_INDEX_PATH}" "${DOWNLOAD_TEMP}/index" normal download_sig "${DOWNLOAD_INDEX_PATH}.asc" "${DOWNLOAD_TEMP}/index.asc" normal fi gpg_validate "${DOWNLOAD_TEMP}/index.asc" # Parse it echo "" echo "---" printf "DIST\tRELEASE\tARCH\tVARIANT\tBUILD\n" echo "---" while IFS=';' read -r f1 f2 f3 f4 f5 f6; do [ -n "${DOWNLOAD_DIST}" ] && [ "$f1" != "${DOWNLOAD_DIST}" ] && continue [ -n "${DOWNLOAD_RELEASE}" ] && [ "$f2" != "${DOWNLOAD_RELEASE}" ] && continue [ -n "${DOWNLOAD_ARCH}" ] && [ "$f3" != "${DOWNLOAD_ARCH}" ] && continue [ -n "${DOWNLOAD_VARIANT}" ] && [ "$f4" != "${DOWNLOAD_VARIANT}" ] && continue [ -z "${f5}" ] || [ -z "${f6}" ] && continue printf "%s\t%s\t%s\t%s\t%s\n" "${f1}" "${f2}" "${f3}" "${f4}" "${f5}" unset f1 f2 f3 f4 f5 f6 done < "${DOWNLOAD_TEMP}/index" echo "---" if [ "${DOWNLOAD_LIST_IMAGES}" = "true" ]; then exit 1 fi # Interactive mode echo "" if [ -z "${DOWNLOAD_DIST}" ]; then echo "Distribution: " read -r DOWNLOAD_DIST fi if [ -z "${DOWNLOAD_RELEASE}" ]; then echo "Release: " read -r DOWNLOAD_RELEASE fi if [ -z "${DOWNLOAD_ARCH}" ]; then echo "Architecture: " read -r DOWNLOAD_ARCH fi echo "" fi # Setup the cache if [ "${DOWNLOAD_TARGET}" = "system" ]; then LXC_CACHE_BASE="${LOCALSTATEDIR}/cache/lxc/" else LXC_CACHE_BASE="${HOME}/.cache/lxc/" fi # Allow the setting of the LXC_CACHE_PATH with the usage of environment variables. LXC_CACHE_PATH="${LXC_CACHE_PATH:-"${LXC_CACHE_BASE}"}" LXC_CACHE_PATH="${LXC_CACHE_PATH}/download/${DOWNLOAD_DIST}" LXC_CACHE_PATH="${LXC_CACHE_PATH}/${DOWNLOAD_RELEASE}/${DOWNLOAD_ARCH}/" LXC_CACHE_PATH="${LXC_CACHE_PATH}/${DOWNLOAD_VARIANT}" if [ -d "${LXC_CACHE_PATH}" ]; then if [ "${DOWNLOAD_FLUSH_CACHE}" = "true" ]; then echo "Flushing the cache..." rm -Rf "${LXC_CACHE_PATH}" elif [ "${DOWNLOAD_FORCE_CACHE}" = "true" ]; then DOWNLOAD_USE_CACHE="true" else DOWNLOAD_USE_CACHE="true" if [ -e "$(relevant_file expiry)" ]; then if [ "$(cat "$(relevant_file expiry)")" -lt "$(date +%s)" ]; then echo "The cached copy has expired, re-downloading..." DOWNLOAD_USE_CACHE="false" fi fi fi fi # Download what's needed if [ "${DOWNLOAD_USE_CACHE}" = "false" ]; then # Initialize GPG gpg_setup # Grab the index DOWNLOAD_INDEX_PATH="/meta/1.0/index-${DOWNLOAD_MODE}" echo "Downloading the image index" if ! download_file "${DOWNLOAD_INDEX_PATH}.${DOWNLOAD_COMPAT_LEVEL}" "${DOWNLOAD_TEMP}/index" noexit || ! download_sig "${DOWNLOAD_INDEX_PATH}.${DOWNLOAD_COMPAT_LEVEL}.asc" "${DOWNLOAD_TEMP}/index.asc" noexit; then download_file "${DOWNLOAD_INDEX_PATH}" "${DOWNLOAD_TEMP}/index" normal download_sig "${DOWNLOAD_INDEX_PATH}.asc" "${DOWNLOAD_TEMP}/index.asc" normal fi gpg_validate "${DOWNLOAD_TEMP}/index.asc" # Parse it while IFS=';' read -r f1 f2 f3 f4 f5 f6; do if [ "${f1}" != "${DOWNLOAD_DIST}" ] || \ [ "${f2}" != "${DOWNLOAD_RELEASE}" ] || \ [ "${f3}" != "${DOWNLOAD_ARCH}" ] || \ [ "${f4}" != "${DOWNLOAD_VARIANT}" ] || \ [ -z "${f6}" ]; then continue fi DOWNLOAD_BUILD="${f5}" DOWNLOAD_URL="${f6}" unset f1 f2 f3 f4 f5 f6 break done < "${DOWNLOAD_TEMP}/index" if [ -z "${DOWNLOAD_URL}" ]; then echo "ERROR: Couldn't find a matching image" 1>&1 exit 1 fi if [ -d "${LXC_CACHE_PATH}" ] && [ -f "${LXC_CACHE_PATH}/build_id" ] && \ [ "$(cat "${LXC_CACHE_PATH}/build_id")" = "${DOWNLOAD_BUILD}" ]; then echo "The cache is already up to date" echo "Using image from local cache" else # Download the actual files echo "Downloading the rootfs" download_file "${DOWNLOAD_URL}/rootfs.tar.xz" "${DOWNLOAD_TEMP}/rootfs.tar.xz" normal download_sig "${DOWNLOAD_URL}/rootfs.tar.xz.asc" "${DOWNLOAD_TEMP}/rootfs.tar.xz.asc" normal gpg_validate "${DOWNLOAD_TEMP}/rootfs.tar.xz.asc" echo "Downloading the metadata" download_file "${DOWNLOAD_URL}/meta.tar.xz" "${DOWNLOAD_TEMP}/meta.tar.xz" normal download_sig "$DOWNLOAD_URL/meta.tar.xz.asc" "${DOWNLOAD_TEMP}/meta.tar.xz.asc" normal gpg_validate "${DOWNLOAD_TEMP}/meta.tar.xz.asc" if [ -d "${LXC_CACHE_PATH}" ]; then rm -Rf "${LXC_CACHE_PATH}" fi mkdir -p "${LXC_CACHE_PATH}" mv "${DOWNLOAD_TEMP}/rootfs.tar.xz" "${LXC_CACHE_PATH}" if ! tar Jxf "${DOWNLOAD_TEMP}/meta.tar.xz" -C "${LXC_CACHE_PATH}"; then echo "ERROR: Invalid rootfs tarball." 2>&1 exit 1 fi echo "${DOWNLOAD_BUILD}" > "${LXC_CACHE_PATH}/build_id" if [ -n "${LXC_MAPPED_UID}" ] && [ "${LXC_MAPPED_UID}" != "-1" ]; then # As the script is run in strict mode (set -eu), all commands # exiting with non 0 would make the script stop. # || true or || : (more portable) prevents that. chown -R "${LXC_MAPPED_UID}" "${LXC_CACHE_BASE}" >/dev/null 2>&1 || : fi if [ -n "${LXC_MAPPED_GID}" ] && [ "${LXC_MAPPED_GID}" != "-1" ]; then chgrp -R "${LXC_MAPPED_GID}" "${LXC_CACHE_BASE}" >/dev/null 2>&1 || : fi echo "The image cache is now ready" fi else echo "Using image from local cache" fi # Unpack the rootfs echo "Unpacking the rootfs" EXCLUDES="" excludelist=$(relevant_file excludes) if [ -f "${excludelist}" ]; then while read -r line; do EXCLUDES="${EXCLUDES} --exclude=${line}" done < "${excludelist}" fi # Do not surround ${EXCLUDES} by quotes. This does not work. The solution could # use array but this is not POSIX compliant. The only POSIX compliant solution # is to use a function wrapper, but the latter can't be used here as the args # are dynamic. We thus need to ignore the warning brought by shellcheck. # shellcheck disable=SC2086 tar --anchored ${EXCLUDES} --numeric-owner -xpJf "${LXC_CACHE_PATH}/rootfs.tar.xz" -C "${LXC_ROOTFS}" mkdir -p "${LXC_ROOTFS}/dev/pts/" # Setup the configuration configfile="$(relevant_file config)" fstab="$(relevant_file fstab)" if [ ! -e "${configfile}" ]; then echo "ERROR: meta tarball is missing the configuration file" 1>&2 exit 1 fi ## Extract all the network config entries sed -i -e "/lxc.net.0/{w ${LXC_PATH}/config-network" -e "d}" "${LXC_PATH}/config" ## Extract any other config entry sed -i -e "/lxc./{w ${LXC_PATH}/config-auto" -e "d}" "${LXC_PATH}/config" ## Append the defaults { echo "" echo "# Distribution configuration" cat "$configfile" } >> "${LXC_PATH}/config" ## Add the container-specific config { echo "" echo "# Container specific configuration" if [ -e "${LXC_PATH}/config-auto" ]; then cat "${LXC_PATH}/config-auto" rm "${LXC_PATH}/config-auto" fi if [ -e "${fstab}" ]; then echo "lxc.mount.fstab = ${LXC_PATH}/fstab" fi echo "lxc.uts.name = ${LXC_NAME}" } >> "${LXC_PATH}/config" ## Re-add the previously removed network config if [ -e "${LXC_PATH}/config-network" ]; then { echo "" echo "# Network configuration" cat "${LXC_PATH}/config-network" rm "${LXC_PATH}/config-network" } >> "${LXC_PATH}/config" fi TEMPLATE_FILES="${LXC_PATH}/config" # Setup the fstab if [ -e "${fstab}" ]; then cp "${fstab}" "${LXC_PATH}/fstab" TEMPLATE_FILES="${TEMPLATE_FILES};${LXC_PATH}/fstab" fi # Look for extra templates if [ -e "$(relevant_file templates)" ]; then while read -r line; do fullpath="${LXC_ROOTFS}/${line}" [ ! -e "${fullpath}" ] && continue TEMPLATE_FILES="${TEMPLATE_FILES};${fullpath}" done < "$(relevant_file templates)" fi # Replace variables in all templates OLD_IFS=${IFS} IFS=";" for file in ${TEMPLATE_FILES}; do [ ! -f "${file}" ] && continue sed -i "s#LXC_NAME#${LXC_NAME}#g" "${file}" sed -i "s#LXC_PATH#${LXC_PATH}#g" "${file}" sed -i "s#LXC_ROOTFS#${LXC_ROOTFS}#g" "${file}" sed -i "s#LXC_TEMPLATE_CONFIG#${LXC_TEMPLATE_CONFIG}#g" "${file}" sed -i "s#LXC_HOOK_DIR#${LXC_HOOK_DIR}#g" "${file}" done IFS=${OLD_IFS} # prevent mingetty from calling vhangup(2) since it fails with userns on CentOS / Oracle if [ -f "${LXC_ROOTFS}/etc/init/tty.conf" ]; then sed -i 's|mingetty|mingetty --nohangup|' "${LXC_ROOTFS}/etc/init/tty.conf" fi if [ -n "${LXC_MAPPED_UID}" ] && [ "${LXC_MAPPED_UID}" != "-1" ]; then chown "${LXC_MAPPED_UID}" "${LXC_PATH}/config" "${LXC_PATH}/fstab" >/dev/null 2>&1 || : fi if [ -n "${LXC_MAPPED_GID}" ] && [ "${LXC_MAPPED_GID}" != "-1" ]; then chgrp "${LXC_MAPPED_GID}" "${LXC_PATH}/config" "${LXC_PATH}/fstab" >/dev/null 2>&1 || : fi if [ -e "$(relevant_file create-message)" ]; then echo "" echo "---" cat "$(relevant_file create-message)" fi exit 0