unprivileged containers

This commit is contained in:
Jörg Thalheim 2015-08-14 09:32:44 +00:00
parent ea047816d3
commit 8a1f0e87c3
10 changed files with 467 additions and 2 deletions

1
.gitignore vendored
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container.json

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.gitmodules vendored Normal file
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[submodule "fuidshift"]
path = fuidshift
url = https://github.com/Mic92/fuidshift.git

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container-eva.json Normal file
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{
"zone": {
"soa": "ns2.higgsboson.tk.",
"serial": 8,
"refresh": "1H",
"hostmaster": "hostmaster.higgsboson.tk",
"domain": "eva.higgsboson.tk",
"ttl": 300,
"a": "188.226.214.194",
"aaaa": "2a03:b0c0:0:1010::3d:b001",
"retry": "4H",
"expire": "3W",
"minimum": "1D",
"v4_subnet": "172.23.75.64/26",
"ula_subnet": "fdc0:4992:6a6d:300::2/64",
"v6_subnet": "2a03:b0c0:0000:1010:0000:0000:003d:b001/124"
},
"network": {
"eve": {
"ipv4": "172.23.75.65",
"ipv6": "2a03:b0c0:0000:1010:0000:0000:003d:b002",
"lxc": false
},
"bridge": {
"ipv4": "172.23.75.65",
"ipv6": "2a03:b0c0:0000:1010:0000:0000:003d:b002",
"ula": "fdc0:4992:6a6d:300::2",
"lxc": false
},
"base": {
"ipv4": "172.23.75.66",
"ipv6": "2a03:b0c0:0:1010::3d:b003",
"ula": "fdc0:4992:6a6d:300::3"
},
"dn42": {
"ipv4": "172.23.75.64/32",
"ipv6": "2a03:b0c0:0:1010::3d:b001/128",
"ula": "fdc0:4992:6a6d:300::1/128"
},
"mail": {
"ipv4": "172.23.75.67/32",
"ipv6": "2a03:b0c0:0:1010::3d:b004/128",
"ula": "fdc0:4992:6a6d:300::4/128"
}
}
}

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default-eva.conf Normal file
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lxc.include = /etc/lxc/base.conf
lxc.hook.pre-mount = /etc/lxc/hooks/mount-base-rootfs
## this line is used by: /usr/share/lxc/templates/lxc-overlay
# CREATE_HOOKS="setup-machine-id remove-journal cleanup-lxc-config create-lxc-config update-zone update-digitalocean-rnds"

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fuidshift Submodule

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Subproject commit 4a8d24f7bcbfa539f06c021ed0ba13823ce87678

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require "fileutils" require "fileutils"
require "pry"
module Lxc module Lxc
module Utils module Utils
def self.safe_write(path, content) def self.safe_write(path, content)
dir = File.dirname(path) dir = File.dirname(path)
unless Dir.exist?(dir) begin
FileUtils.mkdir_p(dir) FileUtils.mkdir_p(dir)
rescue Errno::EEXIST #don't care
end end
temp_path = path.to_s + ".tmp" temp_path = path.to_s + ".tmp"
File.open(temp_path, 'w+') do |f| File.open(temp_path, 'w+') do |f|

5
hooks/mount-base-rootfs Executable file
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#!/bin/bash
set -e
mount -o bind /lxc/base/rootfs /lxc/${LXC_NAME}/rootfs
mount -o remount,ro,bind /lxc/base/rootfs /lxc/${LXC_NAME}/rootfs

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initial.conf Normal file
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lxc.network.type = empty

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#!/bin/bash
#
# template script for generating Arch Linux container for LXC
#
#
# lxc: linux Container library
# Authors:
# Alexander Vladimirov <alexander.idkfa.vladimirov@gmail.com>
# John Lane <lxc@jelmail.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
# Detect use under userns (unsupported)
# Make sure the usual locations are in PATH
export PATH=$PATH:/usr/sbin:/usr/bin:/sbin:/bin
set -x
# defaults
arch=$(uname -m)
default_path="/var/lib/lxc"
default_locale="en-US.UTF-8"
default_timezone="UTC"
pacman_config="/etc/pacman.conf"
common_config="/usr/share/lxc/config/common.conf"
shared_config="/usr/share/lxc/config/archlinux.common.conf"
# by default, install 'base' except the kernel
pkg_blacklist="linux"
base_packages=()
for pkg in $(pacman -Sqg base); do
[ "${pkg_blacklist#*$pkg}" = "$pkg_blacklist" ] && base_packages+=($pkg)
done
declare -a additional_packages
# split comma-separated string into an array
# ${1} - string to split
# ${2} - separator (default is ",")
# ${result} - result value on success
split_string() {
local ifs=${IFS}
IFS="${2:-,}"
read -a result < <(echo "${1}")
IFS=${ifs}
return 0
}
[ -f /etc/arch-release ] && is_arch=true
# Arch-specific preconfiguration for container
configure_arch() {
# on ArchLinux, read defaults from host systemd configuration
if [ "${is_arch}" ]; then
cp -p /etc/locale.conf /etc/locale.gen "${rootfs_path}/etc/"
else
echo "LANG=${default_locale}" > "${rootfs_path}/etc/locale.conf"
if [ -e "${rootfs_path}/etc/locale.gen" ]; then
sed -i 's@^#\(en_US\.UTF-8\)@\1@' "${rootfs_path}/etc/locale.gen"
if [ ! "${default_locale}" = "en_US.UTF-8" ]; then
echo "${default_locale} ${default_locale##*.}" >> \
"${rootfs_path}/etc/locale.gen"
fi
fi
fi
# hostname and nameservers
echo "${name}" > "${rootfs_path}/etc/hostname"
while read r; do
[ "${r#nameserver}" = "$r" ] || echo "$r"
done < /etc/resolv.conf > "${rootfs_path}/etc/resolv.conf"
# chroot and configure system
arch-chroot "${rootfs_path}" /bin/bash -s << EOF
mkdir /run/lock
locale-gen
ln -s /usr/share/zoneinfo/${default_timezone} /etc/localtime
# set default boot target
ln -s /lib/systemd/system/multi-user.target /etc/systemd/system/default.target
# override getty@.service for container ttys
sed -e 's/^ConditionPathExists=/# ConditionPathExists=/' \
-e 's/After=dev-%i.device/After=/' \
< /lib/systemd/system/getty\@.service \
> /etc/systemd/system/getty\@.service
# initialize pacman keyring
pacman-key --init
pacman-key --populate archlinux
EOF
# enable getty on active ttys
local nttys=$(cat "${config_path}/config" ${shared_config} ${common_config} | grep "^lxc.tty" | head -n1 | cut -d= -f2 | tr -d "[:blank:]")
local devttydir=$(cat "${config_path}/config" ${shared_config} ${common_config} | grep "^lxc.devttydir" | head -n1 | cut -d= -f2 | tr -d "[:blank:]")
local devtty=""
# bind getty instances to /dev/<devttydir>/tty* if lxc.devttydir is set
[ -n "${devttydir}" ] && devtty="${devttydir}-"
if [ ${nttys:-0} -gt 1 ]; then
( cd "${rootfs_path}/etc/systemd/system/getty.target.wants"
for i in $(seq 1 $nttys); do ln -sf "../getty@.service" "getty@${devtty}tty${i}.service"; done )
fi
# update securetty to allow console login if devttydir is set
if [ -n "${devttydir}" ]; then
for i in $(seq 1 ${nttys:-1}); do
echo "${devttydir}/tty${i}" >> "${rootfs_path}/etc/securetty"
done
fi
[ -n "${devttydir}" ] && echo "${devttydir}/console" >> "${rootfs_path}/etc/securetty"
# Arch default configuration allows only tty1-6 for login
[ ${nttys:-0} -gt 6 ] && echo \
"You may want to modify container's /etc/securetty \
file to allow root logins on tty7 and higher"
return 0
}
# write container configuration files
copy_configuration() {
mkdir -p "${config_path}"
local config="${config_path}/config"
echo "lxc.utsname = ${name}" >> "${config}"
grep -q "^lxc.arch" "${config}" 2>/dev/null \
|| echo "lxc.arch = ${arch}" >> "${config}"
grep -q "^lxc.rootfs" "${config}" 2>/dev/null \
|| echo "lxc.rootfs = ${rootfs_path}" >> "${config}"
[ -e "${shared_config}" ] \
&& echo "lxc.include = ${shared_config}" >> "${config}"
if [ $? -ne 0 ]; then
echo "Failed to configure container"
return 1
fi
return 0
}
# install packages within container chroot
install_arch() {
[ "${arch}" != "$(uname -m)" ] && different_arch=true
if [ "${different_arch}" = "true" ]; then
container_pacman_config=$(mktemp)
container_mirrorlist=$(mktemp)
sed -e "s:Architecture =.*:Architecture = ${arch}:g" \
-e "s:/etc/pacman.d/mirrorlist:${container_mirrorlist}:g" \
"${pacman_config}" > "${container_pacman_config}"
sed -e "s:\(x86_64\|\$arch\):${arch}:g" \
/etc/pacman.d/mirrorlist > "${container_mirrorlist}"
pacman_config="${container_pacman_config}"
fi
if ! pacstrap -dcGC "${pacman_config}" "${rootfs_path}" \
${base_packages[@]}; then
echo "Failed to install container packages"
return 1
fi
if [ "${different_arch}" = "true" ]; then
sed -i -e "s:Architecture =.*:Architecture = ${arch}:g" \
"${rootfs_path}"/etc/pacman.conf
cp "${container_mirrorlist}" "${rootfs_path}"/etc/pacman.d/mirrorlist
rm "${container_pacman_config}" "${container_mirrorlist}"
fi
[ -d "${rootfs_path}/lib/modules" ] && ldconfig -r "${rootfs_path}"
return 0
}
usage() {
cat <<EOF
usage:
${1} -n|--name=<container_name> [-p|--path=<path>] [-a|--arch=<arch of the container>]
[-r|--root_password=<root password>] [-P|--packages=<pkg1,pkg2,...>]
[-e|--enable_units=unit1,unit2...] [-d|--disable_units=unit1,unit2...]
[-c|--config=<pacman config path>] [-h|--help]
Mandatory args:
-n,--name container name, used to as an identifier for that container from now on
Optional args:
-p,--path path to where the container rootfs will be created (${default_path})
--rootfs path for actual container rootfs, (${default_path/rootfs)
-P,--packages preinstall additional packages, comma-separated list
-e,--enable_units enable systemd services, comma-separated list
-d,--disable_units disable systemd services, comma-separated list
-c,--config use specified pacman config when installing container packages
-a,--arch use specified architecture instead of host's architecture
-r,--root_password set container root password
-h,--help print this help
EOF
return 0
}
options=$(getopt -o hp:P:e:d:n:c:a:r: -l help,rootfs:,path:,packages:,enable_units:,disable_units:,name:,config:,arch:,root_password:,mapped-uid:,mapped-gid: -- "${@}")
if [ ${?} -ne 0 ]; then
usage $(basename ${0})
exit 1
fi
eval set -- "${options}"
mapped_uid=-1
mapped_gid=-1
while true
do
case "${1}" in
-h|--help) usage ${0} && exit 0;;
-p|--path) path=${2}; shift 2;;
-n|--name) name=${2}; shift 2;;
--rootfs) rootfs_path=${2}; shift 2;;
-P|--packages) additional_packages=${2}; shift 2;;
-e|--enable_units) enable_units=${2}; shift 2;;
-d|--disable_units) disable_units=${2}; shift 2;;
-c|--config) pacman_config=${2}; shift 2;;
-a|--arch) arch=${2}; shift 2;;
-r|--root_password) root_passwd=${2}; shift 2;;
--mapped-uid) mapped_uid=$2; shift 2;;
--mapped-gid) mapped_gid=$2; shift 2;;
--) shift 1; break ;;
*) break ;;
esac
done
if [ -z "${name}" ]; then
echo "missing required 'name' parameter"
exit 1
fi
type pacman >/dev/null 2>&1
if [ ${?} -ne 0 ]; then
echo "'pacman' command is missing, refer to wiki.archlinux.org for information about installing pacman"
exit 1
fi
if [ -z "${path}" ]; then
path="${default_path}/${name}"
fi
if [ "${EUID}" != "0" ]; then
echo "This script should be run as 'root'"
exit 1
fi
if [ -z "$rootfs_path" ]; then
rootfs_path="${path}/rootfs"
fi
config_path="${path}"
revert() {
echo "Interrupted, cleaning up"
lxc-destroy -n "${name}"
rm -rf "${path}/${name}"
rm -rf "${default_path}/${name}"
exit 1
}
trap revert SIGHUP SIGINT SIGTERM
copy_configuration
if [ ${?} -ne 0 ]; then
echo "failed to write configuration file"
rm -rf "${config_path}"
exit 1
fi
if [ ${#additional_packages[@]} -gt 0 ]; then
split_string ${additional_packages}
base_packages+=(${result[@]})
fi
mkdir -p "${rootfs_path}"
install_arch
if [ ${?} -ne 0 ]; then
echo "failed to install Arch Linux"
rm -rf "${config_path}" "${path}"
exit 1
fi
configure_arch
if [ ${?} -ne 0 ]; then
echo "failed to configure Arch Linux for a container"
rm -rf "${config_path}" "${path}"
exit 1
fi
if [ ${#enable_units[@]} -gt 0 ]; then
split_string ${enable_units}
for unit in ${result[@]}; do
[ "${unit##*.}" = "service" ] || unit="${unit}.service"
ln -s "/usr/lib/systemd/system/${unit}" \
"${rootfs_path}/etc/systemd/system/multi-user.target.wants/"
done
fi
if [ ${#disable_units[@]} -gt 0 ]; then
split_string ${disable_units}
for unit in ${result[@]}; do
[ "${unit##*.}" = "service" ] || unit="${unit}.service"
ln -s /dev/null "${rootfs_path}/etc/systemd/system/${unit}"
done
fi
if [ -n "${root_passwd}" ]; then
echo "root:${root_passwd}" | chroot "${rootfs_path}" chpasswd
fi
if [ $mapped_uid -ne -1 ]; then
chown $mapped_uid "$config_path"
chown -R $mapped_uid "$rootfs_path"
fi
if [ $mapped_gid -ne -1 ]; then
chgrp $mapped_gid "$config_path"
chgrp -R $mapped_gid "$rootfs_path"
fi
cat << EOF
Arch Linux container ${name} is successfully created! The configuration is
stored in ${config_path}/config. Please refer to https://wiki.archlinux.org for
information about configuring Arch Linux.
EOF

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templates/lxc-overlay Executable file
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#!/bin/bash
set -ex
add_overlayfs(){
local root_path="$1"
local rootfs="$root_path/rootfs" local path="$2"
local lower="$base_rootfs/${path}"
local upper="$root_path/.${path}-delta"
local work="$root_path/.${path}-work"
[[ -d "$rootfs" ]] || mkdir -p "$rootfs"
[[ -d "$work" ]] || mkdir -p "$work"
[[ -d "$upper" ]] || mkdir -p "$upper"
echo "none $path overlay lowerdir=$lower,upperdir=$upper,workdir=$work 0 0" >> "$root_path/fstab"
}
options=$(getopt -o n:4:6: -l name:,ipv4:,ipv6:,path:,rootfs:,mapped-uid:,mapped-gid: -- "$@")
if [ $? -ne 0 ]; then
usage $(basename $0)
exit 1
fi
eval set -- "$options"
while true
do
case "$1" in
-n|--name) name=$2; shift 2;;
-4|--ipv4) ipv4=$2; shift 2;;
-6|--ipv6) ipv6=$2; shift 2;;
--path) path=$2; shift 2;;
--rootfs) base_rootfs=$2; shift 2;;
--) shift 1; break ;;
*) break ;;
esac
done
if [ -z "${name}" ]; then
echo "missing required 'name' parameter"
exit 1
fi
if [ -z "${path}" ]; then
echo "missing required 'path' parameter"
exit 1
fi
if [ -z "${base_rootfs}" ]; then
echo "missing required 'rootfs' parameter"
exit 1
fi
config="${path}/config"
touch "$path/fstab"
add_overlayfs "$path" "var"
add_overlayfs "$path" "etc"
add_overlayfs "$path" "home"
add_overlayfs "$path" "srv"
add_overlayfs "$path" "mnt"
add_overlayfs "$path" "root"
cat > "$config" <<EOF
lxc.include = /etc/lxc/default.conf
lxc.include = ${path}/local.conf
lxc.rootfs = ${path}/rootfs
lxc.utsname = $name
EOF
touch "$path/local.conf"
export LXC_ROOTFS_PATH="$path/rootfs"
export LXC_NAME=$name
export LXC_CONFIG_FILE="$config"
perl -n -e'/CREATE_HOOKS="([^"]+)"/ && map { system("/etc/lxc/hooks/$_") == 0 or print("executing $_ failed\n") } split(/\s+/, $1)' \
/etc/lxc/default.conf