#!/bin/sh
set -e

# Remove a no-longer used conffile
rm_conffile() {
    local PKGNAME="$1"
    local CONFFILE="$2"

    [ -e "$CONFFILE" ] || return 0

    local md5sum="$(md5sum $CONFFILE | sed -e 's/ .*//')"
    local old_md5sum="$(dpkg-query -W -f='${Conffiles}' $PKGNAME | \
            sed -n -e "\' $CONFFILE ' { s/ obsolete$//; s/.* //; p }")"
    if [ "$md5sum" != "$old_md5sum" ]; then
        echo "Obsolete conffile $CONFFILE has been modified by you."
        echo "Saving as $CONFFILE.dpkg-bak ..."
        mv -f "$CONFFILE" "$CONFFILE".dpkg-bak
    else
        echo "Removing obsolete conffile $CONFFILE ..."
        rm -f "$CONFFILE"
    fi
}

# move_sem(src,targets)
#  rename sem/* items named $src to $targets
#  (with hard links if more than one)
move_sem() {
    local src=$1 f="" targ="" freqid="" dir=/var/lib/cloud/sem
    shift
    # link the remaining targets to src, if it exists
    for f in "${dir}/${src}."*; do
        # if there were no src entries, nothing to do
        [ -f "${f}" ] || return 0
        freqid=${f#${dir}/${src}.} # 'i-abcdefg' or 'always'
        for targ in "$@"; do
            [ -e "${dir}/${targ}.${freqid}" ] && continue
            ln -f "${f}" "${dir}/${targ}.${freqid}"
        done
        rm "${f}"
    done
   return 0
}

fix_ephemeral0_micro() {
   # make ephemeral0 entries in /etc/fstab written by cloudconfig
   # 'nobootwait', so they do not block subsequent boots (LP: #634102)
   local out="" oldver=$1 dev="" adop="nobootwait"
   local s="[[:space:]]" ns="[^[:space:]]" # space and "not space"
   local remain="${s}\+.*" first4=""
   for dev in /dev/sda2 /dev/sdb; do
      first4="${dev}$s\+$ns\+$s\+$ns\+$s\+$ns\+"
      out=$(awk '$1 == dev && $4 ~ /cloudconfig/ &&  $4 !~ op { print $1 ; }' \
         dev="${dev}" "op=${adop}" /etc/fstab) || return 0
      [ -n "${out}" ] || continue
      echo "making ephemeral ${dev} in /etc/fstab ${adop} (LP: #634102)" 1>&2
      sed -i "s|^\(${first4}\)\(${remain}\)|\1,${adop}\2|" /etc/fstab
   done
}

convert_varlib_05x_06x() {
   local url="http://169.254.169.254/2009-04-04/meta-data/instance-id"
   local tout="--connect-timeout .5 --read-timeout .5" 
   local iid="" f="" uptime="" bn=""
   iid=$(wget "${url}" ${tout} --tries 1 -O - 2>/dev/null) || iid=""

   [ -n "${iid}" -a -d /var/lib/cloud ] || return 0
   cd /var/lib/cloud
   mkdir -p "instances/${iid}" "instances/${iid}/sem"
   [ -e instance ] || ln -sf "instances/${iid}" instance
   for f in data/*; do
      [ -f "$f" ] || continue
      case "${f#*/}" in
         user-data.txt.i|user-data.txt|cloud-config.txt)
            mv "${f}" instance/
            ;;
      esac
   done
   [ -f data/cache/obj.pkl ] && mv data/cache/obj.pkl instance/
   for f in sem/*.${iid}; do
      [ -f "${f}" ] || continue
      bn=${f#*/}; bn=${bn%.${iid}}
      case "${bn}" in
         set_defaults) mv "${f}" "instance/sem/config-locale";;
         set_hostname) mv "${f}" "instance/sem/config-set_hostname";;
         *) mv "${f}" "instance/sem/${bn}";;
      esac
   done
   [ ! -f sem/update_hostname.always ] ||
      mv sem/update_hostname.always sem/config-update_hostname.always
   rmdir data/cache 2>/dev/null || :
   rm -f data/available.build

   mkdir -p instance/scripts
   if [ -d data/scripts ]; then
      mv data/scripts/* instance/scripts || :
      rmdir data/scripts || :
   fi
   [ -d data/scripts/* ] && mv data/scripts instance/

   [ ! -e instance/boot-finished ] &&
      [ -f /proc/uptime ] && read uptime other </proc/uptime &&
      echo "${uptime}" > instance/boot-finished || :

   return 0
}

azure_apply_new_instance_id_1506187() {
  # With LP: #1506187, the Azure instance ID detection method was changed
  # to use the DMI data. In order to prevent existing instances from thinking
  # they are new instances, the instance ID needs to be updated here.

  if grep DataSourceAzure /var/lib/cloud/instance/datasource > /dev/null 2>&1; then

     product_id_f="/sys/devices/virtual/dmi/id/product_uuid"
     instance_id_f="/var/lib/cloud/data/instance-id"

     if [ ! -e "${product_id_f}" -o ! -e "${instance_id_f}" ]; then
        return 0
     fi

     # Get the current instance ID's (new and old)
     new_instance_id="$(cat ${product_id_f})"
     old_instance_id="$(cat ${instance_id_f})"

     if [ "${new_instance_id}" = "${old_instance_id}" ]; then
        # this may have been applied for a prior version, i.e. upgrading
        # from 14.04 to 16.04
        return 0

     elif [ -z "${new_instance_id}" -o -z "${old_instance_id}" ]; then
        cat <<EOM

WARNING: Failed to migrate old instance ID to new instance ID.
    Cloud-init may detect this instance as a new instance upon reboot.
    Please see: https://bugs.launchpad.net/bug/1506187

EOM

     elif [ "${new_instance_id}" != "${old_instance_id}" ]; then
        cat <<EOM

AZURE: this instance uses an unstable instance ID. Cloud-init will
    migrate the instance ID from:
            ${old_instance_id}
        to:
            ${new_instance_id}
    For more information about this change, please see:
    https://bugs.launchpad.net/bug/1506187
    https://azure.microsoft.com/en-us/blog/accessing-and-using-azure-vm-unique-id

EOM

        # Write the new instance id
        echo "${new_instance_id}" > /var/lib/cloud/data/instance-id

        # Remove the symlink for the instance
        rm /var/lib/cloud/instance

        # Rename the old instance id to the new one
        mv /var/lib/cloud/instances/${old_instance_id} \
           /var/lib/cloud/instances/${new_instance_id}

        # Link the old id to the new one, just incase
        ln -s /var/lib/cloud/instances/${new_instance_id} \
              /var/lib/cloud/instances/${old_instance_id}

        # Make the active instance the new id
        ln -s /var/lib/cloud/instances/${new_instance_id} \
              /var/lib/cloud/instance
  fi
fi
}

cleanup_lp1552999() {
    local oldver="$1" last_bad_ver="0.7.7~bzr1178"
    dpkg --compare-versions "$oldver" le "$last_bad_ver" || return 0
    local hdir="/var/lib/systemd/deb-systemd-helper-enabled"
    hdir="$hdir/multi-user.target.wants" 
    local edir="/etc/systemd/system/multi-user.target.wants"
    rm -f "$hdir/cloud-config.service" "$hdir/cloud-final.service" \
        "$hdir/cloud-init-local.service" "$hdir/cloud-init.service"
}

case "$1" in
    install|upgrade)
        if dpkg --compare-versions "$2" le "0.5.11-0ubuntu1"; then
            # rename the config entries in sem/ so they're not run again

            # transition names in 0.5.11 had only short name (no config- prefix)
            # so create config- entries for each
            for name in apt-update-upgrade disable-ec2-metadata mounts \
                puppet runcmd ssh updates-check; do
                move_sem ${name} config-${name}
            done

            # 0.5.11 split 'config-misc' into 'updates-check' and 'runcmd'
            move_sem config-misc config-updates-check config-runcmd
        fi

      if dpkg --compare-versions "$2" le "0.5.14-0ubuntu5"; then
         fix_ephemeral0_micro
      fi

      if dpkg --compare-versions "$2" le 0.6.0-0ubuntu1; then
         # convert /var/lib/cloud from 0.5.x layout to 0.6.x
         convert_varlib_05x_06x
      fi

      # 0.6.0 changed 'user-scripts' to config-scripts-user (LP: #1049146)
      if [ -e /var/lib/cloud/instance/sem/user-scripts ]; then
         ln -sf user-scripts /var/lib/cloud/instance/sem/config-scripts-user
      fi

      # 0.7.7-bzr1556 introduced new instance ID source for Azure
      if dpkg --compare-versions "$2" le "0.7.7~bzr1556-0ubuntu1"; then
         azure_apply_new_instance_id_1506187
      fi

      d=/etc/cloud/
      if [ -f "$d/distro.cfg" ] && [ ! -f "$d/cloud.cfg.d/90_dpkg.cfg" ]; then
         echo "moving $d/distro.cfg -> $d/cloud.cfg.d/90_dpkg.cfg"
         [ -d "${d}/cloud.cfg.d" ] || mkdir "${d}/cloud.cfg.d"
         mv "$d/distro.cfg" "$d/cloud.cfg.d/90_dpkg.cfg"
      fi

      cleanup_lp1552999 "$oldver"
esac

#DEBHELPER#