A scheduler script for NZBGet which pauses the queue if using too much of my allocated monthly quota from Internode. E.g. if 30% through the month but used more than 30% of quota, pause, otherwise unpause.

nzbget-quota-checker.sh

#!/usr/bin/env sh

##############################################################################
### NZBGET SCHEDULER SCRIPT                                                ###

# Pause queue when using too much of Internode monthly quota.
#
# It will also unpause the queue once we're behind expected usage.
#
# Note: this script requires the `xmllint` binary (e.g.: from xmllib2-utils)
# and `curl` and `awk` and `perl`.

##############################################################################
### OPTIONS                                                                ###

# Internode Username
#Username=

# Internode Password
#Password=

# Service Identifier (optional if you only have one account with Internode)
#Service=

### NZBGET SCHEDULER SCRIPT                                                ###
##############################################################################

INTERNODE_API="https://customer-webtools-api.internode.on.net/api/v1.5"

INTERNODE_USER="$NZBPO_USERNAME"
INTERNODE_PASS="$NZBPO_PASSWORD"
INTERNODE_SERVICE="$NZBPO_SERVICE"

if [ x = "x$INTERNODE_SERVICE" ]; then
  INTERNODE_SERVICE="[1]"
else
  INTERNODE_SERVICE="[text()=$INTERNODE_SERVICE]"
fi

PATH="/usr/bin:/opt/bin:$PATH"
XML_LINT="`which xmllint`"
CURL="`which curl`"

nzbRun() {
  if [ -z "$NZBOP_APPBIN" ]; then
    echo "[DEBUG] would run: nzbget -c nzbget.conf $*"
  else
    "$NZBOP_APPBIN" -c "$NZBOP_CONFIGFILE" $* >/dev/null 2>/dev/null
  fi
}

pause() {
  nzbRun -P D
}

unpause() {
  nzbRun -U D
}

api() {
  ENDPOINT=$1
  $CURL -k --silent -u "$INTERNODE_USER:$INTERNODE_PASS" "${INTERNODE_API}${ENDPOINT}"
}

path() {
  result="`$XML_LINT --xpath $1 -`"
  echo $result
}

service() {
  services="`api /`"
  service_endpoint="`echo $services | path "string(//service$INTERNODE_SERVICE/@href)"`"
  api $service_endpoint
}

quota() {
  echo $1 | path 'string(//traffic/@quota)'
}

usage() {
  echo $1 | path '//traffic/text()'
}

rollover() {
  echo $1 | path 'string(//traffic/@rollover)'
}

# actual calc command not on my NAS
calc() { awk "BEGIN { print $*}"; }

is() {
  test 1 -eq "`calc \( $* \)`"
}

# Thanks to http://stackoverflow.com/a/4948548/56690. The cleaner solution on that page
# works but the Perl DateTime module isn't on my Synology NAS so I used the uglier version.
daysBetween() {
  perl -le '
    use Time::Local;
    sub to_epoch {
      my ($t) = @_;
      my ($y, $m, $d) = ($t =~ /(\d{4})-(\d{2})-(\d{2})/);
      return timelocal(0, 0, 0, $d+0, $m-1, $y-1900);
    }
    sub diff_days {
      my ($t1, $t2) = @_;
      return int((abs(to_epoch($t2) - to_epoch($t1))) / 86400);
    }
    print diff_days(shift, shift);
  ' $1 $2
}

main() {
  service="`service`"
  usage_endpoint="`echo $service | path 'string(//resource[@type="usage"]/@href)'`"
  history_endpoint="`echo $service | path 'string(//resource[@type="history"]/@href)'`"
  usage="`api $usage_endpoint`"

  first_day="`api $history_endpoint | path 'string(//usage[1]/@day)'`"
  today="`date +"%Y-%m-%d"`"
  rollover="`rollover "$usage"`"
  quota="`quota "$usage"`"
  used="`usage "$usage"`"
  days_in_month="`daysBetween $first_day $rollover`"
  days_into_month="`daysBetween $first_day $today`"
  days_into_month="`calc 1 + $days_into_month`" # count today

  if [ $days_into_month -ge $days_in_month ]; then
    month_perc=100
  else
    month_perc="`calc 100 \* $days_into_month / $days_in_month`"
  fi

  usage_perc="`calc 100 \* $used / $quota`"

  echo "[DETAIL] Today: $today ($days_into_month day(s) or $month_perc% into month)"
  echo "[DETAIL] Month: $first_day to $rollover ($days_in_month day(s))"
  echo "[DETAIL] Usage: $used / $quota bytes ($usage_perc%)"

  # The cut-off for downloading is the % of quota corresponding to how much
  # through our current month we are, unless it's over 90% of the total quota,
  # in which case we should just stop downloading for the month.
  if is $month_perc \>= 90; then
    perc_cap=90
  else
    perc_cap=$month_perc
  fi

  if is $usage_perc \>= $perc_cap; then
    echo "[INFO] Using quota to quickly; pausing"
    pause
  else
    echo "[INFO] Quota to spare; unpausing"
    unpause
  fi
}

main