Monitor Amazon EMR and send XMPP message on completion

watch_and_notify_emr.sh

#! /bin/bash

# A script that watches the running status of Amazon EMR jobs, sending an XMPP
# message upon completion.
#
# A destination jabber account, where the messages are sent, should be supplied
# either as the first argument at invocation or in the environment variable
# JABBER_ACCOUNT.
#
# Dependencies:
# - https://github.com/hapyrus/elastic-mapreduce
# - sendxmpp (available as debian package)


CHECK_INTERVAL_SECONDS=10 # subject to throttling on Amazon, at least 3 secs?
JABBER_ACCOUNT=${1:-$JABBER_ACCOUNT}

function validate_args() {
  if [ -z $JABBER_ACCOUNT ]
  then
    echo "Usage: supply a destination jabber account either as the first"
    echo "argument or in the environment variable JABBER_ACCOUNT"
    exit 1
  fi
}

function list_emr() {
  ./emr --list --active --no-steps
}

function filter_done() {
  grep 'COMPLETED\|FAILED\|WAITING'
}

function send_xmpp() {
  sendxmpp $JABBER_ACCOUNT 2>/dev/null
}

function check_status() {
  read OUT
  if [ ! -z "$OUT" ]
  then
    echo -e "Job is finished:\n$OUT" | send_xmpp
    exit 1
  else
    echo "$(date +'%Y-%m-%d %H:%M:%S'), waiting for job.."
  fi
}

function main() {
  while true
  do
    list_emr | filter_done | check_status

    if [ $? -ne 0 ]
    then
      echo 'done, exiting..'
      exit 1
    fi

    sleep $CHECK_INTERVAL_SECONDS
  done
}

validate_args
main