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#!/bin/bash

###############################################################################
# CONFIG

# AWS config
export AWS_SECRET_KEY="XXXX"
export AWS_ACCESS_KEY="XXXX"
export PATH=$PATH:/usr/local/aws/ec2/bin
export EC2_HOME=/usr/local/aws/ec2/
export JAVA_HOME=/usr/lib/jvm/java-6-openjdk-amd64/
export EC2_URL=https://eu-west-1.ec2.amazonaws.com

# needed for moving the IP
AWS_INSTANCE_ID="XXXX"          # different for each node, ex: i-xxxxxxxx
ELASTIC_IP="XXXX"  # ex: 174.129.253.XXX
###############################################################################


###############################################################################
# For testing purposes delete OCF_ROOT after testing
OCF_ROOT=/usr/lib/ocf/
#
# INIT
: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/resource.d/heartbeat}
if [ -f ${OCF_FUNCTIONS_DIR}/.ocf-shellfuncs ]; then
  . ${OCF_FUNCTIONS_DIR}/.ocf-shellfuncs
fi

USAGE="usage: $0 {start|stop|status|meta-data}";
###############################################################################

meta_data() {
    cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="ElasticIP">
<version>1.0</version>
<longdesc lang="en">
This script manages Amazon EC2 Elastic IP addresses.
</longdesc>
<shortdesc lang="en">Manages Amazon EC2 Elastic IP addresses</shortdesc>

<parameters></parameters>

<actions>
  <action name="start"   timeout="20s" />
  <action name="stop"    timeout="20s" />
  <action name="monitor"  timeout="20s" />
  <action name="meta-data"  timeout="5s" />
</actions>
</resource-agent>
END
}

ip_already_associated() {
  if [ `ec2-describe-addresses | grep "$ELASTIC_IP" | awk '{print $3}'` = "$AWS_INSTANCE_ID" ]; then
      ocf_log info "Elastic IP address already associated to the node"
    return $OCF_SUCCESS
  else
      ocf_log err "Elastic IP address not associated to the node"
    return $OCF_ERR_GENERIC
  fi
}

ip_start() {
  ip_validate_all || exit $?

  if ip_monitor; then
    ocf_log info "Resource is already running"
    return $OCF_SUCCESS
  fi

  ec2-associate-address "$ELASTIC_IP" -i "$AWS_INSTANCE_ID" > /dev/null

  if [ $? -eq 1 ]; then
    ocf_log info "An error occurred when starting the resource"
    return $OCF_ERR_GENERIC
  fi

  while ! ip_monitor; do
    ocf_log debug "Resource has not started yet, waiting"
    sleep 1
  done

  ocf_log info "Elastic IP sucessfully associated with the node"
  return $OCF_SUCCESS
}

ip_stop() {
  ip_validate_all || exit $?

  if ip_monitor; then
    ocf_log debug "Resource is currently running"
  else
    ocf_log info "Resource is already stopped"
    return $OCF_SUCCESS
  fi

  ec2-disassociate-address "$ELASTIC_IP" > /dev/null

  if [ $? -eq 0 ]; then
      while ip_monitor; do
        ocf_log debug "Resource has not stopped yet, waiting"
        sleep 1
      done
      ocf_log info "Resource is stopped"
  else
    ocf_log info "An error occurred when stopping the resource"
    exit $OCF_ERR_GENERIC
  fi

  return $OCF_SUCCESS
}

# FIRST approach to monitoring
ip_monitor() {
  ip_validate_all || exit $?

  if ip_already_associated; then
    ping -c 1 $ELASTIC_IP > /dev/null
    if [ $? -eq 0 ]; then
      ocf_log info "Elastic IP responding to ping test, resource test sucessful"
      return $OCF_SUCCESS
    else
      ocf_log err "Elastic IP not responding to ping test, resource test failed"
      return $OCF_ERR_GENERIC
    fi
  else
  ocf_log debug "Resource not running"
  return $OCF_NOT_RUNNING
  fi

  return $OCF_SUCCESS
}

ip_validate_all() {
  which ec2-describe-addresses > /dev/null

  if [ $? -eq 1 ]; then
    ocf_log info "AWS command line tools unavailable"
    return $OCF_ERR_INSTALLED
  elif [ -z "$AWS_SECRET_KEY" ]; then
    ocf_log info "AWS_SECRET_KEY env variable not set"
    return $OCF_ERR_CONFIGURED
  elif [ -z "$AWS_ACCESS_KEY" ]; then
    ocf_log info "AWS_ACCESS_KEY env variable not set"
    return $OCF_ERR_CONFIGURED
  elif [ -z "$EC2_HOME" ]; then
    ocf_log info "EC2_HOME env variable not set"
    return $OCF_ERR_CONFIGURED
  elif [ -z "$JAVA_HOME" ]; then
    ocf_log info "JAVA_HOME env variable not set"
    return $OCF_ERR_CONFIGURED
  elif [ -z "$EC2_URL" ]; then
    ocf_log info "EC2_URL env variable not set"
    return $OCF_ERR_CONFIGURED
  elif [ -z "$AWS_INSTANCE_ID" ]; then
    ocf_log info "AWS_INSTANCE_ID env variable not set"
    return $OCF_ERR_CONFIGURED
  elif [ -z $ELASTIC_IP ]; then
    ocf_log info "ELASTIC_IP env variable not set"
    return $OCF_ERR_CONFIGURED
  fi
  return $OCF_SUCCESS
}

usage() {
    echo $USAGE >&2
    return $1
}

if [ $# -ne 1 ]; then
    usage $OCF_ERR_ARGS
fi

case $1 in
    meta-data)          meta_data;;
    start)              ip_start;;
    stop)               ip_stop;;
    status)             ip_monitor;; # Status is deprecated, monitor replaces it.
    monitor)            ip_monitor;;
    validate-all)       ip_validate_all;;
    usage)              usage $OCF_SUCCESS;;
    *)                  usage $OCF_ERR_UNIMPLEMENTED;;
esac

exit $?