#!/bin/bash
#
#    rabbitmq-relations - relations to be used by formula, referenced
#                         via symlink
#
#    Copyright (C) 2011  Canonical Ltd.
#    Author: Adam Gandelman <adam.gandelman@canonical.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

set -u
FORMULA_DIR=$(dirname $0)
ARG0=${0##*/}

if [[ -e $FORMULA_DIR/rabbitmq-common ]] ; then
  . $FORMULA_DIR/rabbitmq-common
else
  juju-log "rabbitmq-server: ERROR Could not load $FORMULA_DIR/rabbitmq-common"
  exit 1
fi

juju-log "rabbitmq-server: Firing hook $ARG0."

function install_hook() {
  [[ ! `which pwgen` ]] && apt-get -y install pwgen
  DEBIAN_FRONTEND=noninteractive apt-get -qqy \
    install --no-install-recommends rabbitmq-server
  rc=$?

  # give ubuntu user passwd-less sudo for log access 
  echo "ubuntu ALL=(ALL) NOPASSWD:ALL" >/etc/sudoers.d/ubuntu-qa
  chmod 0440 /etc/sudoers.d/ubuntu-qa

  service rabbitmq-server stop
}

function amqp_changed() {
  # Connecting clients should request a username and vhost.
  # In reponse, we generate a password for new users,
  # grant the user access on the default vhost "/",
  # and tell it where to reach us.
  RABBIT_USER=`relation-get username`
  VHOST=`relation-get vhost`
  if [[ -z $RABBIT_USER ]] || [[ -z $VHOST ]] ; then
    juju-log "rabbitmq-server: RABBIT_USER||VHOST not yet received from peer."
    exit 0
  fi
  PASSWD_FILE="/var/run/juju/$RABBIT_USER.passwd"
  if [[ -e $PASSWD_FILE ]] ; then
    PASSWORD=$(cat $PASSWD_FILE)
  else
    PASSWORD=$(pwgen 10 1)
    echo $PASSWORD >$PASSWD_FILE
    chmod 0400 $PASSWD_FILE
  fi
  if ! vhost_exists ; then
    juju-log "rabbitmq-server: Creating vhost $VHOST"
    create_vhost
  fi
  if ! user_exists $RABBIT_USER ; then
    juju-log "rabbitmq-server: Creating user $RABBIT_USER"
    user_create $RABBIT_USER admin || exit 1
  else
    juju-log "rabbitmq-server: user $RABBIT_USER already exists."
  fi
  juju-log "rabbitmq-server: Returning credentials for $RABBIT_USER@$HOSTNAME"
  relation-set hostname=`unit-get private-address`
  relation-set password=$PASSWORD
}

function cluster_joined {
  REMOTE_UNIT_ID=$(echo $JUJU_REMOTE_UNIT | cut -d/ -f2)
  LOCAL_UNIT_ID=$(echo $JUJU_UNIT_NAME | cut -d/ -f2)
  [[ $LOCAL_UNIT_ID -gt $REMOTE_UNIT_ID ]] && echo "Relation greater" && exit 0
  if [[ ! -e $ERLANG_COOKIE ]] ; then
    juju-log "rabbitmq-server: ERROR Could not find cookie at $ERLANG_COOKIE"
    exit 1
  fi
  relation-set cookie=$(cat $ERLANG_COOKIE) host=$HOSTNAME
}

function cluster_changed {
  REMOTE_UNIT_ID=$(echo $JUJU_REMOTE_UNIT | cut -d/ -f2)
  LOCAL_UNIT_ID=$(echo $JUJU_UNIT_NAME | cut -d/ -f2)
  [[ $LOCAL_UNIT_ID -lt $REMOTE_UNIT_ID ]] && echo "Relation lesser" && exit 0

  REMOTE_HOST=$(relation-get host)
  COOKIE_VALUE=$(relation-get cookie)
  [[ -z $REMOTE_HOST ]] || [[ -z $COOKIE_VALUE ]] && \
    juju-log "rabbimtq-server: REMOTE_HOST||COOKIE_VALUE not yet set." \
    exit 0

  service rabbitmq-server stop
  echo -n $COOKIE_VALUE > $ERLANG_COOKIE
  service rabbitmq-server start
  rabbitmqctl reset
  rabbitmqctl cluster rabbit@$HOSTNAME rabbit@$REMOTE_HOST
  rabbitmqctl start_app
}

case $ARG0 in
  "install") install_hook ;;
  "start") service rabbitmq-server status || service rabbitmq-server start ;;
  "stop") service rabbitmq-server status && service rabbitmq-server stop ;;
  "amqp-relation-joined") exit 0 ;;
  "amqp-relation-changed") amqp_changed ;;
  "cluster-relation-joined") cluster_joined ;;
  "cluster-relation-changed") cluster_changed ;;
esac

rc=$?
juju-log "rabbitmq-server: Hook $ARG0 complete. Exiting $rc"
exit $rc