templates/lxc-ubuntu-cloud.in

   1 #!/bin/bash
   2
   3 # template script for generating ubuntu container for LXC based on released
   4 # cloud images.
   5 #
   6 # Copyright © 2012 Serge Hallyn <serge.hallyn@canonical.com>
   7 #
   8 # This program is free software; you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License version 2, as
  10 # published by the Free Software Foundation.
  11
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16
  17 # You should have received a copy of the GNU General Public License along
  18 # with this program; if not, write to the Free Software Foundation, Inc.,
  19 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20 #
  21
  22 set -e
  23
  24 STATE_DIR="@LOCALSTATEDIR@"
  25 HOOK_DIR="@LXCHOOKDIR@"
  26 CLONE_HOOK_FN="$HOOK_DIR/ubuntu-cloud-prep"
  27
  28 if [ -r /etc/default/lxc ]; then
  29     . /etc/default/lxc
  30 fi
  31
  32 am_in_userns() {
  33     [ -e /proc/self/uid_map ] || { echo no; return; }
  34     [ "$(wc -l /proc/self/uid_map | awk '{ print $1 }')" -eq 1 ] || { echo yes; return; }
  35     line=$(awk '{ print $1 " " $2 " " $3 }' /proc/self/uid_map)
  36     [ "$line" = "0 0 4294967295" ] && { echo no; return; }
  37     echo yes
  38 }
  39
  40 in_userns=0
  41 [ $(am_in_userns) = "yes" ] && in_userns=1
  42
  43 copy_configuration()
  44 {
  45     path=$1
  46     rootfs=$2
  47     name=$3
  48     arch=$4
  49     release=$5
  50
  51     if [ $arch = "i386" ]; then
  52         arch="i686"
  53     fi
  54
  55     # if there is exactly one veth network entry, make sure it has an
  56     # associated hwaddr.
  57     nics=`grep -e '^lxc\.network\.type[ \t]*=[ \t]*veth' $path/config | wc -l`
  58     if [ $nics -eq 1 ]; then
  59         grep -q "^lxc.network.hwaddr" $path/config || sed -i -e "/^lxc\.network\.type[ \t]*=[ \t]*veth/a lxc.network.hwaddr = 00:16:3e:$(openssl rand -hex 3| sed 's/\(..\)/\1:/g; s/.$//')" $path/config
  60     fi
  61
  62     grep -q "^lxc.rootfs" $path/config 2>/dev/null || echo "lxc.rootfs = $rootfs" >> $path/config
  63     cat <<EOF >> $path/config
  64 lxc.mount = $path/fstab
  65 lxc.pivotdir = lxc_putold
  66
  67 lxc.devttydir =$ttydir
  68 lxc.tty = 4
  69 lxc.pts = 1024
  70
  71 lxc.utsname = $name
  72 lxc.arch = $arch
  73 lxc.cap.drop = sys_module mac_admin mac_override sys_time
  74
  75 # When using LXC with apparmor, uncomment the next line to run unconfined:
  76 #lxc.aa_profile = unconfined
  77
  78 # To support container nesting on an Ubuntu host, uncomment next two lines:
  79 #lxc.aa_profile = lxc-container-default-with-nesting
  80 #lxc.hook.mount = /usr/share/lxc/hooks/mountcgroups
  81
  82 lxc.hook.clone = ${CLONE_HOOK_FN}
  83
  84 lxc.cgroup.devices.deny = a
  85 # Allow any mknod (but not using the node)
  86 lxc.cgroup.devices.allow = c *:* m
  87 lxc.cgroup.devices.allow = b *:* m
  88 # /dev/null and zero
  89 lxc.cgroup.devices.allow = c 1:3 rwm
  90 lxc.cgroup.devices.allow = c 1:5 rwm
  91 # consoles
  92 lxc.cgroup.devices.allow = c 5:1 rwm
  93 lxc.cgroup.devices.allow = c 5:0 rwm
  94 # /dev/{,u}random
  95 lxc.cgroup.devices.allow = c 1:9 rwm
  96 lxc.cgroup.devices.allow = c 1:8 rwm
  97 lxc.cgroup.devices.allow = c 136:* rwm
  98 lxc.cgroup.devices.allow = c 5:2 rwm
  99 # rtc
 100 lxc.cgroup.devices.allow = c 254:0 rm
 101 # fuse
 102 lxc.cgroup.devices.allow = c 10:229 rwm
 103 # tun
 104 lxc.cgroup.devices.allow = c 10:200 rwm
 105 # full
 106 lxc.cgroup.devices.allow = c 1:7 rwm
 107 # hpet
 108 lxc.cgroup.devices.allow = c 10:228 rwm
 109 # kvm
 110 lxc.cgroup.devices.allow = c 10:232 rwm
 111 EOF
 112
 113     cat <<EOF > $path/fstab
 114 proc            proc         proc    nodev,noexec,nosuid 0 0
 115 sysfs           sys          sysfs defaults  0 0
 116 /sys/fs/fuse/connections sys/fs/fuse/connections none bind 0 0
 117 /sys/kernel/debug sys/kernel/debug none bind 0 0
 118 /sys/kernel/security sys/kernel/security none bind 0 0
 119 EOF
 120
 121     # unprivileged user can't mknod these.  One day we may allow
 122     # that in the kernel, but not right now.  So let's just bind
 123     # mount the files from the host.
 124     if [ $in_userns -eq 1 ]; then
 125         for dev in null tty urandom console; do
 126             touch $rootfs/dev/$dev
 127             echo "/dev/$dev dev/$dev    none bind 0 0" >> $path/fstab
 128         done
 129     fi
 130
 131     # rmdir /dev/shm for containers that have /run/shm
 132     # I'm afraid of doing rm -rf $rootfs/dev/shm, in case it did
 133     # get bind mounted to the host's /run/shm.  So try to rmdir
 134     # it, and in case that fails move it out of the way.
 135     if [ ! -L $rootfs/dev/shm ] && [ -d $rootfs/run/shm ] && [ -e $rootfs/dev/shm ]; then
 136         mv $rootfs/dev/shm $rootfs/dev/shm.bak
 137         ln -s /run/shm $rootfs/dev/shm
 138     fi
 139
 140     return 0
 141 }
 142
 143 usage()
 144 {
 145     cat <<EOF
 146 LXC Container configuration for Ubuntu Cloud images.
 147
 148 Generic Options
 149 [ -r | --release <release> ]: Release name of container, defaults to host
 150 [ --rootfs <path> ]: Path in which rootfs will be placed
 151 [ -a | --arch ]: Arhcitecture of container, defaults to host arcitecture
 152 [ -T | --tarball ]: Location of tarball
 153 [ -d | --debug ]: Run with 'set -x' to debug errors
 154 [ -s | --stream]: Use specified stream rather than 'released'
 155
 156 Additionally, clone hooks can be passed through (ie, --userdata).  For those,
 157 see:
 158   $CLONE_HOOK_FN --help
 159 EOF
 160     return 0
 161 }
 162
 163 options=$(getopt -o a:hp:r:n:Fi:CLS:T:ds:u: -l arch:,help,rootfs:,path:,release:,name:,flush-cache,hostid:,auth-key:,cloud,no_locales,tarball:,debug,stream:,userdata: -- "$@")
 164 if [ $? -ne 0 ]; then
 165     usage $(basename $0)
 166     exit 1
 167 fi
 168 eval set -- "$options"
 169
 170 # default release is precise, or the systems release if recognized
 171 release=precise
 172 if [ -f /etc/lsb-release ]; then
 173     . /etc/lsb-release
 174     rels=$(ubuntu-distro-info --supported 2>/dev/null) ||
 175         rels="lucid natty oneiric precise quantal raring saucy"
 176     for r in $rels; do
 177         [ "$DISTRIB_CODENAME" = "$r" ] && release="$r"
 178     done
 179 fi
 180
 181 # Code taken from debootstrap
 182 if [ -x /usr/bin/dpkg ] && /usr/bin/dpkg --print-architecture >/dev/null 2>&1; then
 183     arch=`/usr/bin/dpkg --print-architecture`
 184 elif type udpkg >/dev/null 2>&1 && udpkg --print-architecture >/dev/null 2>&1; then
 185     arch=`/usr/bin/udpkg --print-architecture`
 186 else
 187     arch=$(uname -m)
 188     if [ "$arch" = "i686" ]; then
 189         arch="i386"
 190     elif [ "$arch" = "x86_64" ]; then
 191         arch="amd64"
 192     elif [ "$arch" = "armv7l" ]; then
 193         # note: arm images don't exist before oneiric;  are called armhf in
 194         # precise and later;  and are not supported by the query, so we don't actually
 195         # support them yet (see check later on).  When Query2 is available,
 196         # we'll use that to enable arm images.
 197         arch="armhf"
 198     fi
 199 fi
 200
 201 debug=0
 202 hostarch=$arch
 203 cloud=0
 204 locales=1
 205 flushcache=0
 206 stream="released"
 207 cloneargs=()
 208 while true
 209 do
 210     case "$1" in
 211     -h|--help)         usage $0 && exit 0;;
 212     -p|--path)         path=$2; shift 2;;
 213     -n|--name)         name=$2; shift 2;;
 214     -F|--flush-cache)  flushcache=1; shift 1;;
 215     -r|--release)      release=$2; shift 2;;
 216     -a|--arch)         arch=$2; shift 2;;
 217     -T|--tarball)      tarball=$2; shift 2;;
 218     -d|--debug)        debug=1; shift 1;;
 219     -s|--stream)       stream=$2; shift 2;;
 220     --rootfs)          rootfs=$2; shift 2;;
 221     -L|--no?locales)   cloneargs[${#cloneargs[@]}]="--no-locales"; shift 1;;
 222     -i|--hostid)       cloneargs[${#cloneargs[@]}]="--hostid=$2"; shift 2;;
 223     -u|--userdata)     cloneargs[${#cloneargs[@]}]="--userdata=$2"; shift 2;;
 224     -C|--cloud)        cloneargs[${#cloneargs[@]}]="--cloud"; shift 1;;
 225     -S|--auth-key)     cloneargs[${#cloneargs[@]}]="--auth-key=$2"; shift 2;;
 226     --)                shift 1; break ;;
 227         *)              break ;;
 228     esac
 229 done
 230
 231 cloneargs=( "--name=$name" "${cloneargs[@]}" )
 232
 233 if [ $debug -eq 1 ]; then
 234     set -x
 235 fi
 236
 237 if [ "$arch" == "i686" ]; then
 238     arch=i386
 239 fi
 240
 241 if [ $arch != "i386" -a $arch != "amd64" -a $arch != "armhf" -a $arch != "armel" ]; then
 242     echo "Only i386, amd64, armel and armhf are supported by the ubuntu cloud template."
 243     exit 1
 244 fi
 245
 246 if [ $hostarch != "i386" -a $hostarch != "amd64" -a $hostarch != "armhf" -a $hostarch != "armel" ]; then
 247     echo "Only i386, amd64, armel and armhf are supported as host."
 248     exit 1
 249 fi
 250
 251 if [ $hostarch = "amd64" -a $arch != "amd64" -a $arch != "i386" ]; then
 252     echo "can't create $arch container on $hostarch"
 253     exit 1
 254 fi
 255
 256 if [ $hostarch = "i386" -a $arch != "i386" ]; then
 257     echo "can't create $arch container on $hostarch"
 258     exit 1
 259 fi
 260
 261 if [ $hostarch = "armhf" -o $hostarch = "armel" ] && \
 262    [ $arch != "armhf" -a $arch != "armel" ]; then
 263     echo "can't create $arch container on $hostarch"
 264     exit 1
 265 fi
 266
 267 if [ "$stream" != "daily" -a "$stream" != "released" ]; then
 268     echo "Only 'daily' and 'released' streams are supported"
 269     exit 1
 270 fi
 271
 272 if [ -z "$path" ]; then
 273     echo "'path' parameter is required"
 274     exit 1
 275 fi
 276
 277 if [ "$(id -u)" != "0" ]; then
 278     echo "This script should be run as 'root'"
 279     exit 1
 280 fi
 281
 282 # detect rootfs
 283 config="$path/config"
 284 if [ -z "$rootfs" ]; then
 285     if grep -q '^lxc.rootfs' $config 2>/dev/null ; then
 286         rootfs=`grep 'lxc.rootfs =' $config | awk -F= '{ print $2 }'`
 287     else
 288         rootfs=$path/rootfs
 289     fi
 290 fi
 291
 292 type ubuntu-cloudimg-query
 293 type wget
 294
 295 # determine the url, tarball, and directory names
 296 # download if needed
 297 cache="$STATE_DIR/cache/lxc/cloud-$release"
 298
 299 mkdir -p $cache
 300
 301 if [ -n "$tarball" ]; then
 302     url2="$tarball"
 303 else
 304     url1=`ubuntu-cloudimg-query $release $stream $arch --format "%{url}\n"`
 305     url2=`echo $url1 | sed -e 's/.tar.gz/-root\0/'`
 306 fi
 307
 308 filename=`basename $url2`
 309
 310 wgetcleanup()
 311 {
 312     rm -f $filename
 313 }
 314
 315 buildcleanup()
 316 {
 317     cd $rootfs
 318     umount -l $cache/$xdir || true
 319     rm -rf $cache
 320 }
 321
 322 # if the release doesn't have a *-rootfs.tar.gz, then create one from the
 323 # cloudimg.tar.gz by extracting the .img, mounting it loopback, and creating
 324 # a tarball from the mounted image.
 325 build_root_tgz()
 326 {
 327     url=$1
 328     filename=$2
 329
 330     xdir=`mktemp -d -p .`
 331     tarname=`basename $url`
 332     imgname="$release-*-cloudimg-$arch.img"
 333     trap buildcleanup EXIT SIGHUP SIGINT SIGTERM
 334     if [ $flushcache -eq 1 -o ! -f $cache/$tarname ]; then
 335         rm -f $tarname
 336         echo "Downloading cloud image from $url"
 337         wget $url || { echo "Couldn't find cloud image $url."; exit 1; }
 338     fi
 339     echo "Creating new cached cloud image rootfs"
 340     tar --wildcards -zxf $tarname $imgname
 341     mount -o loop $imgname $xdir
 342     (cd $xdir; tar zcf ../$filename .)
 343     umount $xdir
 344     rm -f $tarname $imgname
 345     rmdir $xdir
 346     echo "New cloud image cache created"
 347     trap EXIT
 348     trap SIGHUP
 349     trap SIGINT
 350     trap SIGTERM
 351 }
 352
 353 do_extract_rootfs() {
 354
 355     cd $cache
 356     if [ $flushcache -eq 1 ]; then
 357         echo "Clearing the cached images"
 358         rm -f $filename
 359     fi
 360
 361     trap wgetcleanup EXIT SIGHUP SIGINT SIGTERM
 362     if [ ! -f $filename ]; then
 363         wget $url2 || build_root_tgz $url1 $filename
 364     fi
 365     trap EXIT
 366     trap SIGHUP
 367     trap SIGINT
 368     trap SIGTERM
 369
 370     echo "Extracting container rootfs"
 371     mkdir -p $rootfs
 372     cd $rootfs
 373     tar -zxf $cache/$filename
 374 }
 375
 376 if [ -n "$tarball" ]; then
 377     do_extract_rootfs
 378 else
 379     mkdir -p "$STATE_DIR/lock/subsys/"
 380     (
 381         flock -x 200
 382         do_extract_rootfs
 383     ) 200>"$STATE_DIR/lock/subsys/lxc-ubuntu-cloud"
 384 fi
 385
 386 copy_configuration $path $rootfs $name $arch $release
 387
 388 "$CLONE_HOOK_FN" "${cloneargs[@]}" "$rootfs"
 389
 390 echo "Container $name created."
 391 exit 0
 392
 393 # vi: ts=4 expandtab