#!/bin/sh -e

. /usr/share/debconf/confmodule

set -f # disable pathname expansion
db_capb escape # to support carriage return / multi-line values

debug() {
   [ "${_CI_UPGRADE_DEBUG:-0}" = "0" ] && return 0
   echo "$@" 1>&2 || :
}

update_cfg() {
   # takes filename, header, new object (in yaml), optionally 'remover'
   # and merges new into existing object in filename, and then updates file
   # remover a string that means "delete existing entry"
   python3 -c '
import sys, yaml

def update(src, cand):
    if not (isinstance(src, dict) and isinstance(cand, dict)):
        return cand
    for k, v in cand.items():
        # if the candidate has _ as value, delete source
        if v == REMOVER:
            if k in src:
                del src[k]
            continue
        if k not in src:
            src[k] = v
        else:
            src[k] = update(src[k], v)
    return src

(fname, header, newyaml) = sys.argv[1:4]
REMOVER = object
if len(sys.argv) == 5:
   REMOVER = sys.argv[4]
newcfg = yaml.load(newyaml)

with open(fname, "r") as fp:
    cfg = yaml.load(fp)
if not cfg: cfg = {}

cfg = update(cfg, newcfg)

with open(fname, "w") as fp:
    fp.write(header + "\n")
    fp.write(yaml.dump(cfg))' "$@"
}

handle_preseed_maas() {
   local cfg_file="/etc/cloud/cloud.cfg.d/90_dpkg_maas.cfg"
   local md_url="" creds_all="" c_key="" t_key="" t_sec="" c_sec="";

   db_get "cloud-init/maas-metadata-url" && md_url="$RET" || :
   db_get "cloud-init/maas-metadata-credentials" && creds_all="$RET" || :

   # nothing to do
   [ -n "$md_url" -o -n "$creds_all" ] || return 0

   # change a url query string format into : delimited
   if [ -n "$creds_all" -a "${creds_all#*&}" != "${creds_all}" ]; then
      # the command here ends up looking like:
      # python3 -c '...' 'oauth_consumer_key=v1&oauth_token_key=v2...' \
      #   oauth_consumer_key oauth_token_key oauth_token_secret
      creds_all=$(python3 -c 'from six.moves.urllib.parse import parse_qs;
import sys;
keys = parse_qs(sys.argv[1])
for k in sys.argv[2:]:
   sys.stdout.write("%s:" % keys.get(k,[""])[0])' "$creds_all" \
   oauth_consumer_key oauth_token_key oauth_token_secret
)
   fi

   # now, if non-empty creds_all is: consumer_key:token_key:token_secret
   if [ -n "$creds_all" ]; then
      OIFS="$IFS"; IFS=:; set -- $creds_all; IFS="$OIFS"
      c_key=$1; t_key=$2; t_sec=$3
   fi

   if [ "$md_url" = "_" -a "${c_key}:${t_key}:${t_sec}" = "_:_:_" ]; then
      # if all these values were '_', the delete value, just delete the file.
      rm -f "$cfg_file"
   else
      local header="# written by cloud-init debian package per preseed entries
# cloud-init/{maas-metadata-url,/maas-metadata-credentials}"

      local pair="" k="" v="" pload="" orig_umask=""
      for pair in "metadata_url:$md_url" "consumer_key:${c_key}" \
         "token_key:${t_key}" "token_secret:$t_sec"; do
         k=${pair%%:*}
         v=${pair#${k}:}
         [ -n "$v" ] && pload="${pload} $k: \"$v\","
      done

      # '_' would indicate "delete", otherwise, existing entries are left
      orig_umask=$(umask)
      umask 066
      : >> "$cfg_file" && chmod 600 "$cfg_file"
      update_cfg "$cfg_file" "$header" "datasource: { MAAS: { ${pload%,} } }" _
      umask ${orig_umask}
   fi

   # now clear the database of the values, as they've been consumed
   db_unregister "cloud-init/maas-metadata-url" || :
   db_unregister "cloud-init/maas-metadata-credentials" || :
}

handle_preseed_local_cloud_config() {
   local ccfg="" debconf_name="cloud-init/local-cloud-config"
   local cfg_file="/etc/cloud/cloud.cfg.d/90_dpkg_local_cloud_config.cfg"
   local header="# written by cloud-init debian package per preseed entry
# $debconf_name"

   db_get "${debconf_name}" && ccfg="$RET" || :

   if [ "$ccfg" = "_" ]; then
      rm -f "$cfg_file"
   elif [ -n "$ccfg" ]; then
      { echo "$header"; echo "$ccfg"; } > "$cfg_file"
   fi
   db_unregister "${debconf_name}" || :
}

fix_1336855() {
  ### Begin fix for LP: 1336855
  # fix issue where cloud-init misidentifies the location of grub and
  # where grub misidentifies the location of the device

  # if cloud-init's grub module did not run, then it did not break anything.
  [ -f /var/lib/cloud/instance/sem/config_grub_dpkg ] || return 0

  # This bug only happened on /dev/xvda devices
  [ -b /dev/xvda ] || return 0

  # we can't fix the system without /proc/cmdline
  [ -r /proc/cmdline ] || return 0

  # Don't do anything unless we have grub
  [ -x /usr/sbin/grub-install ] || return 0

  # First, identify the kernel device for the parent.
  for parm in $(cat /proc/cmdline); do
       dev=$(echo $parm | awk -F\= '{print$NF}')
       case $parm in
           root=UUID*)  [ -d /dev/disk/by-uuid ] &&
                            root_dev=$(readlink -f /dev/disk/by-uuid/$dev);;
           root=LABEL*) [ -d /dev/disk/by-label ] &&
                            root_dev=$(readlink -f /dev/disk/by-label/$dev);;
           root=/dev*)  [ -d /dev ] &&
                            root_dev=$(readlink -f $dev);;
       esac
       [ -n "$root_dev" ] && break
  done

  # Don't continue if we don't have a root directive
  [ -z "$root_dev" ] && return 0

  # Only deal with simple, cloud-based devices
  case $root_dev in
       /dev/vda*|/dev/xvda*|/dev/sda*) ;;
       *) return 0;;
  esac

  # Make sure that we are not chrooted.
  [ "$(stat -c %d:%i /)" != "$(stat -c %d:%i /proc/1/root/.)" ] && return 0

  # Check if we are in a container, i.e. LXC
  if systemd-detect-virt --quiet --container || lxc-is-container 2>/dev/null; then
      return 0
  fi

  # Find out where grub thinks the root device is. Only continue if
  # grub postinst would install/reinstall grub
  db_get grub-pc/install_devices && grub_cfg_dev=${RET} || return 0
  db_get grub-pc/install_devices_empty && grub_dev_empty=${RET} || return 0

  # Find out the parent device for the root device.
  #     example output: sda/sda1
  block_path=$(udevadm info -q path -n $root_dev | awk '-Fblock/' '{print$NF}')

  # Extract the parent device name. This works where the device is a block device
  #     example output: /dev/sda
  parent_dev=$(echo $block_path | awk '-F/' '$1 { if ( $1 ) {print"/dev/"$1}}')
  [ -b "${parent_dev}" ] || return 0

  # Do nothing if the device that the grub postinst would install is already used
  [ "$grub_cfg_dev" = "$parent_dev" -o "$grub_cfg_dev" = "$root_dev" ] && return 0

  # If we get here, do the installation
  echo "Reconfiguring grub install device due to mismatch (LP: #1336855)"
  echo "   Grub should use $parent_dev but is configured for $grub_cfg_dev"
  db_set grub-pc/install_devices "$parent_dev"
  grub-install $parent_dev &&
     echo "Reinstalled grub" ||
     echo "WARNING! Unable to fix grub device mismatch. You may be broken."

}

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

disable_network_config_on_upgrade() {
    local oldver="$1" last_without_net="0.7.7~bzr1182-0ubuntu1"
    if [ ! -f /var/lib/cloud/instance/obj.pkl ]; then
        # this is a fresh system not one that has been booted.
        return 0
    fi
    if dpkg --compare-versions "$oldver" le "$last_without_net"; then
        echo "dpkg upgrade from $oldver" > /var/lib/cloud/data/upgraded-network
    fi
}

fix_azure_upgrade_1611074() {
    # adjust /etc/fstab on azure so boot after resize does not mount
    # /mnt as ntfs and stop re-formatting.
    local fixed_ver="0.7.8-49-1" dspath="/var/lib/cloud/instance/datasource"
    local oldver="$1" tmpf="" r="" wmsg="" me="cloud-init postinst"

    # if not on azure, or not booted with instance/ skip out.
    if [ ! -e "$dspath" ]; then
        debug "no $dspath"
        return 0
    fi
    if ! grep -qi azure "$dspath"; then
        debug "not on azure per $dspath"
        return 0
    fi

    # if there is no /etc/fstab, then nothing to fix.
    if [ ! -e /etc/fstab ]; then
        debug "no /etc/fstab"
        return 0
    fi

    if dpkg --compare-versions "$oldver" ge "$fixed_ver"; then
        debug "previous version was fixed"
        return 0
    fi

    wmsg="WARN: $me failed."
    wmsg="$wmsg Subsequent resize may not update ephemeral correctly."
    tmpf=$(mktemp "${TMPDIR:-/tmp}/cloud-init-upgrade.XXXXXX") || {
        echo "$wmsg (mktemp failed with $?)" 1>&2
        return 0;
    }

    awk '{
        if ($4 !~ /x-systemd.requires/ && $4 ~ /comment=cloudconfig/) {
            sub(/comment=cloudconfig/, "x-systemd.requires=cloud-init.service,comment=cloudconfig")
        }
        printf("%s\n", $0)}' /etc/fstab > "$tmpf" || {
            echo "$wmsg (awk reading of /etc/fstab failed with $?)" 1>&2
            rm -f "$tmpf"
            return 0;
        }
    if cmp /etc/fstab "$tmpf" >/dev/null 2>&1; then
        debug "no changes needed."
    else
        cat "$tmpf" > /etc/fstab || {
            r=$?
            echo "$wmsg (cp $tmpf /etc/fstab failed with $r)"
            echo ==== expected to write the following to /etc/fstab =====
            cat "$tmpf"
            echo ========================================================
            return $r
        } 1>&2
        echo "$me fixed /etc/fstab for x-systemd.requires" 1>&2
    fi
    rm "$tmpf" || :
}


if [ "$1" = "configure" ]; then
   # disable ureadahead (LP: #499520)
   dpkg-divert --package cloud-init --rename --divert \
      /etc/init/ureadahead.conf.disabled --add /etc/init/ureadahead.conf
   if db_get cloud-init/datasources; then
      values="$RET"
      if [ "${values#*MaaS}" != "${values}" ]; then
         # if db had old MAAS spelling, fix it.
         values=$(echo "$values" | sed 's,MaaS,MAAS,g')
         db_set cloud-init/datasources "$values"
      fi
      cat > /etc/cloud/cloud.cfg.d/90_dpkg.cfg <<EOF
# to update this file, run dpkg-reconfigure cloud-init
datasource_list: [ $values ]
EOF
   fi

   # we want to affect apt_pipelining on install, not wait for
   # cloud-init to run it on next boot.
   pipeline_f="/etc/apt/apt.conf.d/90cloud-init-pipelining"
   if [ -f /var/lib/cloud/instance/obj.pkl ]; then
      cloud-init single --name apt-pipelining --frequency once >/dev/null 2>&1 ||
         echo "Warning: failed to setup apt-pipelining" 1>&2
   elif [ ! -f "$pipeline_f" ]; then
      # there was no cloud available, so populate it ourselves.
      cat > "$pipeline_f" <<EOF
//Written by cloud-init per 'apt_pipelining'
Acquire::http::Pipeline-Depth "0";
EOF
   fi

   # if there are maas settings pre-seeded apply them
   handle_preseed_maas

   # if there is generic cloud-config preseed, apply them
   handle_preseed_local_cloud_config

   # fix issue where cloud-init misidentifies the location of grub
   fix_1336855

   # make upgrades disable network changes by cloud-init
   disable_network_config_on_upgrade "$2"

   fix_azure_upgrade_1611074 "$2"
fi

#DEBHELPER#

if [ "$1" = "configure" ]; then
   oldver="$2"
   cleanup_lp1552999 "$oldver"
fi