#!/bin/bash
#
# Do a system upgrade, from a version to the next.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public
# License along with this program.  If not, see
# <http://www.gnu.org/licenses/>.

# Load
source $APP_BASE/lib/hydra/functions || exit 1
hydra_config_load

# Parameters
TMP="/tmp"
STATE="$TMP/system-upgrade"
ENV="$TMP/system-upgrade-env"

# Command line arguments
BASENAME="`basename $0`"
NEXTRELEASE="$1"

# Proceed to the next upgrade stage
function hydra_system_upgrade_stage {
  STAGE="$1"
  echo $STAGE > $STATE
  hydra_system_upgrade_$STAGE
}

# Set and check upgrade environment
function hydra_system_upgrade_env {
  # Available releases
  #release="`facter lsbdistcodename`" # this doesn't work on squeeze
  release="`facter 2> /dev/null | grep lsbdistcodename | sed -e 's/lsbdistcodename => //'`"
  nextrelease="`hydra_next_debian_release $release`"

  # Is a virtual machine?
  virtual="`facter 2> /dev/null | grep virtual | grep -v '^is_virtual' | sed -e 's/virtual => //'`"

  # Save environment
  echo "release=$release"          > $ENV
  echo "nextrelease=$nextrelease" >> $ENV
  echo "nextrelease=$nextrelease" >> $ENV
  echo "virtual=$virtual"         >> $ENV

  # Check release
  if [ "$?" != "0" ]; then
    echo "Unsupported release"
    exit 1
  fi

  # Check optional parameter
  if [ ! -z "$NEXTRELEASE" ]; then
    if [ "$NEXTRELEASE" == "$release" ]; then
      echo "System is already upgraded to $NEXTRELEASE"
      exit 1
    fi

    if [ "$NEXTRELEASE" != "$nextrelease" ]; then
      echo "Cannot upgrade: next release for this system is $nextrelease"
      exit 1
    fi
  fi

  # Set next  state
  hydra_system_upgrade_stage prepare
}

# Prepare the environment for a system upgrade
function hydra_system_upgrade_prepare {
  # Ensure puppet is stopped during the process
  if [ -e "/etc/default/puppet" ]; then
    echo "Disabling puppet agent..."
    sed -i -e 's/START=yes/START=no/' /etc/default/puppet
    service puppet stop
  fi

  # Configure apt for the next debian release
  echo ""
  echo "Updating apt configuration..."
  sed -i -e "s/$release/$nextrelease/g" /etc/apt/sources.list

  if [ -e "/etc/apt/preferences" ]; then
    sed -i -e "s/$release/$nextrelease/g" /etc/apt/preferences
  fi

  sed -i -e 's|^deb http://backports.debian.org/debian-backports|#deb http://backports.debian.org/debian-backports|' /etc/apt/sources.list

  # These will be generated by puppet and can be safely removed
  rm -f /etc/apt/sources.list.d/*
  rm -f /etc/apt/preferences.d/*

  # These might lead in upgrade errors
  if [ "$virtual" == "vserver" ] && [ "$nextrelease" == "wheezy" ]; then
    apt-get remove makedev -y
    apt-get remove colord  -y
  fi

  # Set next  state
  hydra_system_upgrade_stage download
}

# Update package listing and download new packages
function hydra_system_upgrade_download {
  echo ""
  echo "Updating package listing..."
  apt-get update
  echo ""
  echo "Downloading packages..."
  apt-get dist-upgrade -d -y
  hydra_system_upgrade_stage upgrade
}

# Proceed with the actual upgrade
function hydra_system_upgrade_upgrade {
  echo ""
  echo "Upgrading the system..."
  DEBIAN_FRONTEND=noninteractive apt-get dist-upgrade

  if [ "$?" != "0" ]; then
    echo "Upgrade failed. Please fix it manually and run this command again."
    exit 1
  fi

  hydra_system_upgrade_stage custom
}

# Custom upgrade procedures
function hydra_system_upgrade_custom {
  if [ "$nextrelease" == "wheezy" ]; then
    # Old suhosin config
    rm -f /etc/php5/conf.d/suhosin.ini

    # This has to be manually installed again
    if [ -f "/etc/php5/cli/conf.d/uploadprogress.ini" ]; then
      pecl uninstall uploadprogress
      pecl install   uploadprogress
    fi
  fi

  if [ "$nextrelease" == "jessie" ]; then
    # We're using a masterless puppet setup, so no agent
    apt-get install puppet-common
    apt-get purge puppet

    # Purge old monitoring infrastructure
    apt-get purge 'munin*' 'nagios*'
    rm -rf /etc/nagios* /etc/munin* /etc/munin* /usr/share/munin*

    # Cleanup old scripts
    rm -f /usr/local/sbin/check-puppetd.sh
    rm -f remove /etc/cron.d/puppetd
  fi

  hydractl trac-upgrade
  hydra_system_upgrade_stage cleanup
}

# Cleanup procedures
function hydra_system_upgrade_cleanup {
  apt-get autoremove --purge -y
  apt-get clean
}

# Check for root user
if [ "`whoami`" != "root" ]; then
  echo "please run this command as root"
  exit 1
fi

# Initialize
if [ ! -e "$STATE" ]; then
  hydra_system_upgrade_env
else
  # Resume from the previous state
  STAGE="`cat $STATE`"

  # Restore environment
  if [ -e "$ENV" ]; then
    source $ENV
  fi

  hydra_install_package facter
  hydra_system_upgrade_$STAGE
fi

# Teardown
rm -f $STATE
rm -f $ENV