Added templates/lxc-centos for CentOS containers.

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

#!/bin/bash

#
# template script for generating centos container for LXC

#
# lxc: linux Container library

# Authors:
# Daniel Lezcano <daniel.lezcano@free.fr>
# Ramez Hanna <rhanna@informatiq.org>
# Fajar A. Nugraha <github@fajar.net>
# Michael H. Warfield <mhw@WittsEnd.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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

#Configurations
arch=$(arch)
cache_base=@LOCALSTATEDIR@/cache/lxc/centos/$arch
default_path=@LXCPATH@
# We really need something better here!
root_password=root

lxc_network_type=veth
lxc_network_link=lxcbr0

# is this centos?
# Alow for weird remixes like the Raspberry Pi
#
# Use the Mitre standard CPE identifier for the release ID if possible...
# This may be in /etc/os-release or /etc/system-release-cpe.  We
# should be able to use EITHER.  Give preference to /etc/os-release for now.

if [ -e /etc/os-release ]
then
# This is a shell friendly configuration file.  We can just source it.
# What we're looking for in here is the ID, VERSION_ID and the CPE_NAME
    . /etc/os-release
    echo "Host CPE ID from /etc/os-release: ${CPE_NAME}"
fi

if [ "${CPE_NAME}" = "" -a -e /etc/system-release-cpe ]
then
    CPE_NAME=$(head -n1 /etc/system-release-cpe)
    CPE_URI=$(expr ${CPE_NAME} : '\([^:]*:[^:*]\)')
    if [ "${CPE_URI}" != "cpe:/o" ]
    then
        CPE_NAME=
    else
        echo "Host CPE ID from /etc/system-release-cpe: ${CPE_NAME}"
        # Probably a better way to do this but sill remain posix
        # compatible but this works, shrug...
        # Must be nice and not introduce convenient bashisms here.
        ID=$(expr ${CPE_NAME} : '[^:]*:[^:]*:[^:]*:\([^:]*\)')
        VERSION_ID=$(expr ${CPE_NAME} : '[^:]*:[^:]*:[^:]*:[^:]*:\([^:]*\)')
    fi
fi

if [ "${CPE_NAME}" != "" -a "${ID}" = "centos" -a "${VERSION_ID}" != "" ]
then
    centos_host_ver=${VERSION_ID}
    is_centos=true
elif [ -e /etc/redhat-release ]
then
    # Only if all other methods fail, try to parse the redhat-release file.
    centos_host_ver=$( sed -e '/^CentOS /!d' -e 's/CentOS*\srelease\s*\([0-9][0-9]*\)\s.*/\1/' < /etc/redhat-release )
    if [ "$centos_host_ver" != "" ]
    then
        is_centos=true
    fi
fi

# Map a few architectures to their generic Centos repository archs.
#
# CentOS currently doesn't support ARM but it's copied here from
# the Fedora template for completeness and that it will in the future.
#
# The two ARM archs are a bit of a guesstimate for the v5 and v6
# archs.  V6 should have hardware floating point (Rasberry Pi).
# The "arm" arch is safer (no hardware floating point).  So
# there may be cases where we "get it wrong" for some v6 other
# than RPi.
case "$arch" in
i686) arch=i386 ;;
armv3l|armv4l|armv5l) arch=arm ;;
armv6l|armv7l|armv8l) arch=armhfp ;;
esac

force_mknod()
{
    # delete a device node if exists, and create a new one
    rm -f $2 && mknod -m $1 $2 $3 $4 $5
}

configure_centos()
{

    # disable selinux in centos
    mkdir -p $rootfs_path/selinux
    echo 0 > $rootfs_path/selinux/enforce

    # Also kill it in the /etc/selinux/config file if it's there...
    if [[ -f $rootfs_path/etc/selinux/config ]]
    then
        sed -i '/^SELINUX=/s/.*/SELINUX=disabled/' $rootfs_path/etc/selinux/config
    fi

    # Nice catch from Dwight Engen in the Oracle template.
    # Wantonly plagerized here with much appreciation.
    if [ -f $rootfs_path/usr/sbin/selinuxenabled ]; then
        mv $rootfs_path/usr/sbin/selinuxenabled $rootfs_path/usr/sbin/selinuxenabled.lxcorig
        ln -s /bin/false $rootfs_path/usr/sbin/selinuxenabled
    fi

    # This is a known problem and documented in RedHat bugzilla as relating
    # to a problem with auditing enabled.  This prevents an error in
    # the container "Cannot make/remove an entry for the specified session"
    sed -i '/^session.*pam_loginuid.so/s/^session/# session/' ${rootfs_path}/etc/pam.d/login
    sed -i '/^session.*pam_loginuid.so/s/^session/# session/' ${rootfs_path}/etc/pam.d/sshd

   # configure the network using the dhcp
    cat <<EOF > ${rootfs_path}/etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=dhcp
ONBOOT=yes
HOSTNAME=${UTSNAME}
NM_CONTROLLED=no
TYPE=Ethernet
MTU=${MTU}
EOF

    # set the hostname
    cat <<EOF > ${rootfs_path}/etc/sysconfig/network
NETWORKING=yes
HOSTNAME=${UTSNAME}
EOF

    # set minimal hosts
    cat <<EOF > $rootfs_path/etc/hosts
127.0.0.1 localhost $name
EOF

    # set minimal fstab
    cat <<EOF > $rootfs_path/etc/fstab
/dev/root               /                       rootfs   defaults        0 0
none                    /dev/shm                tmpfs    nosuid,nodev    0 0
EOF

    # create lxc compatibility init script
    if [ "$release" = "6" ]; then
        cat <<EOF > $rootfs_path/etc/init/lxc-sysinit.conf
start on startup
env container

pre-start script
        if [ "x$container" != "xlxc" -a "x$container" != "xlibvirt" ]; then
                stop;
        fi
        initctl start tty TTY=console
        rm -f /var/lock/subsys/*
        rm -f /var/run/*.pid
        telinit 3
        exit 0;
end script
EOF
    elif [ "$release" = "5" ]; then
        cat <<EOF > $rootfs_path/etc/rc.d/lxc.sysinit
#! /bin/bash
rm -f /etc/mtab /var/run/*.{pid,lock} /var/lock/subsys/*
rm -rf {/,/var}/tmp/*
echo "/dev/root               /                       rootfs   defaults        0 0" > /etc/mtab
exit 0
EOF
        chmod 755 $rootfs_path/etc/rc.d/lxc.sysinit
        sed -i 's|si::sysinit:/etc/rc.d/rc.sysinit|si::bootwait:/etc/rc.d/lxc.sysinit|'  $rootfs_path/etc/inittab
        sed -i 's|^1:|co:2345:respawn:/sbin/mingetty console\n1:|' $rootfs_path/etc/inittab
        sed -i 's|^\([56]:\)|#\1|' $rootfs_path/etc/inittab
    fi

    dev_path="${rootfs_path}/dev"
    rm -rf $dev_path
    mkdir -p $dev_path
    mknod -m 666 ${dev_path}/null c 1 3
    mknod -m 666 ${dev_path}/zero c 1 5
    mknod -m 666 ${dev_path}/random c 1 8
    mknod -m 666 ${dev_path}/urandom c 1 9
    mkdir -m 755 ${dev_path}/pts
    mkdir -m 1777 ${dev_path}/shm
    mknod -m 666 ${dev_path}/tty c 5 0
    mknod -m 666 ${dev_path}/tty0 c 4 0
    mknod -m 666 ${dev_path}/tty1 c 4 1
    mknod -m 666 ${dev_path}/tty2 c 4 2
    mknod -m 666 ${dev_path}/tty3 c 4 3
    mknod -m 666 ${dev_path}/tty4 c 4 4
    mknod -m 600 ${dev_path}/console c 5 1
    mknod -m 666 ${dev_path}/full c 1 7
    mknod -m 600 ${dev_path}/initctl p
    mknod -m 666 ${dev_path}/ptmx c 5 2

    echo "setting root passwd to $root_password"
    echo "root:$root_password" | chroot $rootfs_path chpasswd

    # This will need to be enhanced for CentOS 7 when systemd
    # comes into play...   /\/\|=mhw=|\/\/

    return 0
}

configure_centos_init()
{
    sed -i 's|.sbin.start_udev||' ${rootfs_path}/etc/rc.sysinit
    sed -i 's|.sbin.start_udev||' ${rootfs_path}/etc/rc.d/rc.sysinit
    if [ "$release" = "6" ]; then
        chroot ${rootfs_path} chkconfig udev-post off
    fi
    chroot ${rootfs_path} chkconfig network on
}

download_centos()
{

    # check the mini centos was not already downloaded
    INSTALL_ROOT=$cache/partial
    mkdir -p $INSTALL_ROOT
    if [ $? -ne 0 ]; then
    echo "Failed to create '$INSTALL_ROOT' directory"
    return 1
    fi

    # download a mini centos into a cache
    echo "Downloading centos minimal ..."
    YUM="yum --installroot $INSTALL_ROOT -y --nogpgcheck"
    PKG_LIST="yum initscripts passwd rsyslog vim-minimal openssh-server openssh-clients dhclient chkconfig rootfiles policycoreutils"

    # use temporary repository definition
    REPO_FILE=$INSTALL_ROOT/etc/yum.repos.d/lxc-centos-temp.repo
    mkdir -p $(dirname $REPO_FILE)
    cat <<EOF > $REPO_FILE
[base]
name=CentOS-$release - Base
mirrorlist=http://mirrorlist.centos.org/?release=$release&arch=$arch&repo=os

[updates]
name=CentOS-$release - Updates
mirrorlist=http://mirrorlist.centos.org/?release=$release&arch=$arch&repo=updates
EOF

    # create minimal device nodes, needed for "yum install" and "yum update" process
    mkdir -p $INSTALL_ROOT/dev
    force_mknod 666 $INSTALL_ROOT/dev/null c 1 3
    force_mknod 666 $INSTALL_ROOT/dev/urandom c 1 9

    $YUM install $PKG_LIST

    if [ $? -ne 0 ]; then
        echo "Failed to download the rootfs, aborting."
        return 1
    fi

    # use same nameservers as hosts, needed for "yum update later"
    cp /etc/resolv.conf $INSTALL_ROOT/etc/

    # check whether rpmdb is under $HOME
    if [ ! -e $INSTALL_ROOT/var/lib/rpm/Packages -a -e $INSTALL_ROOT/$HOME/.rpmdb/Packages ]; then
        echo "Fixing rpmdb location ..."
        mv $INSTALL_ROOT/$HOME/.rpmdb/[A-Z]* $INSTALL_ROOT/var/lib/rpm/
        rm -rf $INSTALL_ROOT/$HOME/.rpmdb
        chroot $INSTALL_ROOT rpm --rebuilddb 2>/dev/null
    fi

    # check whether rpmdb version is correct
    chroot $INSTALL_ROOT rpm --quiet -q yum 2>/dev/null
    ret=$?

    # if "rpm -q" doesn't work due to rpmdb version difference,
    # then we need to redo the process using the newly-installed yum
    if [ $ret -gt 0 ]; then
        echo "Reinstalling packages ..."
        mv $REPO_FILE $REPO_FILE.tmp
        mkdir $INSTALL_ROOT/etc/yum.repos.disabled
        mv $INSTALL_ROOT/etc/yum.repos.d/*.repo $INSTALL_ROOT/etc/yum.repos.disabled/
        mv $REPO_FILE.tmp $REPO_FILE
        mkdir -p $INSTALL_ROOT/$INSTALL_ROOT/etc
        cp /etc/resolv.conf $INSTALL_ROOT/$INSTALL_ROOT/etc/
        mkdir -p $INSTALL_ROOT/$INSTALL_ROOT/dev
        mknod -m 666 $INSTALL_ROOT/$INSTALL_ROOT/dev/null c 1 3
        mknod -m 666 $INSTALL_ROOT/$INSTALL_ROOT/dev/urandom c 1 9
        mkdir -p $INSTALL_ROOT/$INSTALL_ROOT/var/cache/yum
        cp -al $INSTALL_ROOT/var/cache/yum/* $INSTALL_ROOT/$INSTALL_ROOT/var/cache/yum/
        chroot $INSTALL_ROOT $YUM install $PKG_LIST
        if [ $? -ne 0 ]; then
            echo "Failed to download the rootfs, aborting."
            return 1
        fi
        mv $INSTALL_ROOT/$INSTALL_ROOT $INSTALL_ROOT.tmp
        rm -rf $INSTALL_ROOT
        mv $INSTALL_ROOT.tmp $INSTALL_ROOT
    fi

    rm -f $REPO_FILE
    rm -rf $INSTALL_ROOT/var/cache/yum/*

    mv "$INSTALL_ROOT" "$cache/rootfs"
    echo "Download complete."

    return 0
}

copy_centos()
{

    # make a local copy of the mini centos
    echo -n "Copying rootfs to $rootfs_path ..."
    #cp -a $cache/rootfs-$arch $rootfs_path || return 1
    # i prefer rsync (no reason really)
    mkdir -p $rootfs_path
    rsync -a $cache/rootfs/ $rootfs_path/
    return 0
}

update_centos()
{
    YUM="chroot $cache/rootfs yum -y --nogpgcheck"
    $YUM update
    if [ $? -ne 0 ]; then
        return 1
    fi
    $YUM clean packages
}

install_centos()
{
    mkdir -p /var/lock/subsys/
    (
    flock -x 200
    if [ $? -ne 0 ]; then
        echo "Cache repository is busy."
        return 1
    fi

    echo "Checking cache download in $cache/rootfs ... "
    if [ ! -e "$cache/rootfs" ]; then
        download_centos
        if [ $? -ne 0 ]; then
            echo "Failed to download 'centos base'"
            return 1
        fi
    else
        echo "Cache found. Updating..."
        update_centos
        if [ $? -ne 0 ]; then
            echo "Failed to update 'centos base', continuing with last known good cache"
        else
            echo "Update finished"
        fi
    fi

    echo "Copy $cache/rootfs to $rootfs_path ... "
    copy_centos
    if [ $? -ne 0 ]; then
        echo "Failed to copy rootfs"
        return 1
    fi

    return 0

    ) 200>/var/lock/subsys/lxc

    return $?
}

copy_configuration()
{

    mkdir -p $config_path
    cat <<EOF >> $config_path/config
lxc.utsname = $utsname
lxc.tty = 4
lxc.pts = 1024
lxc.rootfs = $rootfs_path
lxc.mount  = $config_path/fstab
lxc.cap.drop = sys_module mac_admin mac_override sys_time

lxc.autodev = $auto_dev

# example simple networking setup, uncomment to enable
#lxc.network.type = $lxc_network_type
#lxc.network.flags = up
#lxc.network.link = $lxc_network_link
#lxc.network.name = eth0
# additional example for veth network type, static MAC address,
# and persistent veth device name on host side
#lxc.network.hwaddr = 00:16:3e:77:52:20
#lxc.network.veth.pair = v-$name-e0

#cgroups
lxc.cgroup.devices.deny = a
# /dev/null and zero
lxc.cgroup.devices.allow = c 1:3 rwm
lxc.cgroup.devices.allow = c 1:5 rwm
# consoles
lxc.cgroup.devices.allow = c 5:1 rwm
lxc.cgroup.devices.allow = c 5:0 rwm
lxc.cgroup.devices.allow = c 4:0 rwm
lxc.cgroup.devices.allow = c 4:1 rwm
# /dev/{,u}random
lxc.cgroup.devices.allow = c 1:9 rwm
lxc.cgroup.devices.allow = c 1:8 rwm
lxc.cgroup.devices.allow = c 136:* rwm
lxc.cgroup.devices.allow = c 5:2 rwm
# rtc
lxc.cgroup.devices.allow = c 254:0 rwm
EOF

    cat <<EOF > $config_path/fstab
proc            proc         proc    nodev,noexec,nosuid 0 0
devpts          dev/pts      devpts defaults 0 0
sysfs           sys          sysfs defaults  0 0
EOF

    if [ $? -ne 0 ]; then
    echo "Failed to add configuration"
    return 1
    fi

    return 0
}

clean()
{

    if [ ! -e $cache ]; then
    exit 0
    fi

    # lock, so we won't purge while someone is creating a repository
    (
    flock -x 200
    if [ $? != 0 ]; then
        echo "Cache repository is busy."
        exit 1
    fi

    echo -n "Purging the download cache for centos-$release..."
    rm --preserve-root --one-file-system -rf $cache && echo "Done." || exit 1
    exit 0

    ) 200>/var/lock/subsys/lxc
}

usage()
{
    cat <<EOF
usage:
    $1 -n|--name=<container_name>
        [-p|--path=<path>] [-c|--clean] [-R|--release=<CentOS_release>] [-A|--arch=<arch of the container>]
        [-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, defaults to /var/lib/lxc. The container config will go under /var/lib/lxc in that case
  -c,--clean        clean the cache
  -R,--release      Centos release for the new container. if the host is Centos, then it will defaultto the host's release.
     --fqdn         fully qualified domain name (FQDN) for DNS and system naming
  -A,--arch         NOT USED YET. Define what arch the container will be [i686,x86_64]
  -h,--help         print this help
EOF
    return 0
}

options=$(getopt -o hp:n:cR: -l help,path:,rootfs:,name:,clean,release:,fqdn: -- "$@")
if [ $? -ne 0 ]; then
    usage $(basename $0)
    exit 1
fi
eval set -- "$options"

while true
do
    case "$1" in
        -h|--help)      usage $0 && exit 0;;
        -p|--path)      path=$2; shift 2;;
        --rootfs)       rootfs=$2; shift 2;;
        -n|--name)      name=$2; shift 2;;
        -c|--clean)     clean=$2; shift 2;;
        -R|--release)   release=$2; shift 2;;
        --fqdn)         utsname=$2; shift 2;;
        --)             shift 1; break ;;
        *)              break ;;
    esac
done

if [ ! -z "$clean" -a -z "$path" ]; then
    clean || exit 1
    exit 0
fi

if [ -z "${utsname}" ]; then
    utsname=${name}
fi

# This follows a standard "resolver" convention that an FQDN must have
# at least two dots or it is considered a local relative host name.
# If it doesn't, append the dns domain name of the host system.
#
# This changes one significant behavior when running
# "lxc_create -n Container_Name" without using the
# --fqdn option.
#
# Old behavior:
#    utsname and hostname = Container_Name
# New behavior:
#    utsname and hostname = Container_Name.Domain_Name

if [ $(expr "$utsname" : '.*\..*\.') = 0 ]; then
    if [ -n "$(dnsdomainname)" ]; then
        utsname=${utsname}.$(dnsdomainname)
    fi
fi

type yum >/dev/null 2>&1
if [ $? -ne 0 ]; then
    echo "'yum' command is missing"
    exit 1
fi

if [ -z "$path" ]; then
    path=$default_path/$name
fi

if [ -z "$release" ]; then
    if [ "$is_centos" -a "$centos_host_ver" ]; then
        release=$centos_host_ver
    else
        echo "This is not a centos host and release missing, defaulting to 6 use -R|--release to specify release"
        release=6
    fi
fi

# CentOS 7 and above should run systemd.  We need autodev enabled to keep
# systemd from causing problems.
if [ $release -gt 6 ]; then
    auto_dev="1"
else
    auto_dev="0"
fi

if [ "$(id -u)" != "0" ]; then
    echo "This script should be run as 'root'"
    exit 1
fi


if [ -z "$rootfs_path" ]; then
    rootfs_path=$path/rootfs
    # check for 'lxc.rootfs' passed in through default config by lxc-create
    if grep -q '^lxc.rootfs' $path/config 2>/dev/null ; then
        rootfs_path=`grep 'lxc.rootfs =' $path/config | awk -F= '{ print $2 }'`
    fi
fi
config_path=$default_path/$name
cache=$cache_base/$release

revert()
{
    echo "Interrupted, so cleaning up"
    lxc-destroy -n $name
    # maybe was interrupted before copy config
    rm -rf $path
    rm -rf $default_path/$name
    echo "exiting..."
    exit 1
}

trap revert SIGHUP SIGINT SIGTERM

copy_configuration
if [ $? -ne 0 ]; then
    echo "failed write configuration file"
    exit 1
fi

install_centos
if [ $? -ne 0 ]; then
    echo "failed to install centos"
    exit 1
fi

configure_centos
if [ $? -ne 0 ]; then
    echo "failed to configure centos for a container"
    exit 1
fi

configure_centos_init

if [ ! -z $clean ]; then
    clean || exit 1
    exit 0
fi
echo "container rootfs and config created, default root password is '$root_password'"
echo "edit the config file to check/enable networking setup"