#!/bin/sh

#
# Rolls back VzLinux to CentOS or RHEL
#

log=/var/log/vzrollback.log
lock=/var/lock/vzrollback.lck

wget="/usr/bin/wget"
wget_options="-q"

check_exit_code()  { if [ $? -ne $1 ]; then echo $2; rm -f $lock; exit 1; fi; }
check_pipestatus()   { if [ $PIPESTATUS -ne $1 ]; then echo $2; rm -f $lock; exit 1; fi; }

backup()
{
BACKUP=/etc/virtuozzo-convert-saved
mkdir -p $BACKUP
cp /etc/redhat-release $BACKUP 2>&1 | tee -a $log
if [ -f /etc/yum.repos.d/vzlinux.repo ]; then
    mv /etc/yum.repos.d/vzlinux.repo $BACKUP >> $log 2>&1 #test if that is the rate path
fi
}

print_help()
{
    cat << EOF >&2
Usage: $0 release_pkg_url

  release_file_url      URL to *-release rpm package
                        (e.g., centos-release)

Example:
  $0 http://mirror.yandex.ru/centos/7.2.1511/os/x86_64/Packages/centos-release-7-2.1511.el7.centos.2.10.x86_64.rpm
EOF
}

if [ -f $lock ] ; then
    if [ -d /proc/$(cat $lock) ] ; then
        echo "$scriptname is already running"
        exit 1
    fi
fi

echo $$ > $lock
check_exit_code 0 "Please run $scriptname as root"

if [ "$#" -ne 1 ]; then
    print_help
    rm -f $lock
    exit 1
fi

RELEASE_PKG=$1
LOGOS_PKG=`basename ${RELEASE_PKG} | cut -f1 -d-`

if [[ -e "${RELEASE_PKG}" ]]; then
    cp "${RELEASE_PKG}" /tmp/os-release.rpm
else
    echo "Downloading ${RELEASE_PKG}" | tee -a $log
    yum install -y wget
    $wget $wget_options ${RELEASE_PKG} -O /tmp/os-release.rpm || exit 1
fi

backup

rpm -e --nodeps vzlinux-release 2>&1 | tee -a $log
check_pipestatus 0 "Unable to remove vzlinux-release"

rpm -i /tmp/os-release.rpm 2>&1 | tee -a $log
check_pipestatus 0 "Unable to install ${RELEASE_PKG}"
rm -f /tmp/os-release.rpm

sed -i s/vzlinux-release/${LOGOS_PKG}-release/ /etc/yum.conf 2>&1 | tee -a $log
sed -i s/virtuozzo-release/${LOGOS_PKG}-release/ /etc/yum.conf 2>&1 | tee -a $log
yum distro-sync -y 2>&1 | tee -a $log
check_pipestatus 0 "Failed to install necessary packages!"

rpm -e --nodeps vzlinux-logos 2>&1 | tee -a $log
check_pipestatus 0 "Failed to remove vzlinux-logos!"

yum install -y ${LOGOS_PKG}-logos 2>&1 | tee -a $log
check_pipestatus 0 "Failed to install ${LOGOS_PKG}-logos!"

rpm -qa | grep kernel | grep vl7 | xargs rpm -e 2>&1 | tee -a $log
check_pipestatus 0 "Failed to remove vzlinux kernel!"

grub2-mkconfig -o /boot/grub2/grub.cfg 2>&1 | tee -a $log
check_pipestatus 0 "Failed to regenerate grub config!"

echo "Rollback is complete! Please reboot your system. You can find complete log in $log"
rm -f $lock
exit 0