using traps to send graphite metrics in bash scripts

graphite_traps.sh

#!/usr/bin/env bash

starttime=$(date +%s)

########
# Set up a set of functions and traps that will emit duration and error counts for this script on exit.
# expects that $GRAPHITE_HOST is set in the environment.
function emit_duration {
  endtime=$(date +%s)
  duration=$(($endtime-$starttime))
  echo "foo.duration  $duration `date +%s`" | nc -w 1 $GRAPHITE_HOST 2003
}

function emit_error {
  # we have to trap exit here so that we don't hit both emit_error and emit_success
  trap - EXIT
  echo "foo.error 1 `date +%s`" | nc -w 1 $GRAPHITE_HOST 2003
}

function emit_success {
  echo "foo.success 1 `date +%s`" | nc -w 1 $GRAPHITE_HOST 2003
}

function success_trap {
  emit_duration; emit_success;
}

function error_trap {
  emit_duration; emit_error;
}

# a reasonable set of things to call an error
trap error_trap HUP INT QUIT PIPE TERM
# the success case
trap success_trap 0
########

# do some things

sleep 10;