#!/bin/sh
### BEGIN INIT INFO
# Provides:          unified-monitoring-agent
# Required-Start:    $network $local_fs
# Required-Stop:     $network $local_fs
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Oracle Unified Agent fluentd distribution
# Description:       unified-monitoring-agent is a fluentd based logs and metrics agents
### END INIT INFO


export PATH=/sbin:/usr/sbin:/bin:/usr/bin

AGENT_NAME=unified-monitoring-agent
AGENT_HOME=/opt/unified-monitoring-agent
AGENT_DEFAULT=/etc/sysconfig/unified-monitoring-agent
AGENT_USER=unified-monitoring-agent
AGENT_GROUP=unified-monitoring-agent
AGENT_RUBY=/opt/unified-monitoring-agent/embedded/bin/ruby
AGENT_BIN_FILE=/usr/sbin/unified-monitoring-agent
AGENT_LOG_FILE=/var/log/unified-monitoring-agent/unified-monitoring-agent.log
AGENT_PID_FILE=/var/run/unified-monitoring-agent/unified-monitoring-agent.pid
AGENT_LOCK_FILE=/var/lock/subsys/unified-monitoring-agent
AGENT_OPTIONS="--use-v1-config"

# timeout can be overridden from /etc/sysconfig/unified-monitoring-agent
STOPTIMEOUT=120

# Read configuration variable file if it is present
if [ -f "${AGENT_DEFAULT}" ]; then
  . "${AGENT_DEFAULT}"
fi

if [ -n "${name}" ]; then
  # backward compatibility
  echo "Warning: Declaring \$name in ${AGENT_DEFAULT} has been deprecated. Use \$AGENT_NAME instead." 1>&2
  AGENT_NAME="${name}"
fi

if [ -n "${prog}" ]; then
  # backward compatibility
  echo "Warning: Declaring \$prog in ${AGENT_DEFAULT} for customizing \$PIDFILE has been deprecated. Use \$AGENT_PID_FILE instead." 1>&2
  if [ -z "${PIDFILE}" ]; then
    AGENT_PID_FILE="//var/run/unified-monitoring-agent/${prog}.pid"
  fi
  AGENT_LOCK_FILE="//var/lock/subsys/${prog}"
  AGENT_PROG_NAME="${prog}"
else
  unset AGENT_PROG_NAME
fi

if [ -n "${process_bin}" ]; then
  # backward compatibility
  echo "Warning: Declaring \$process_bin in ${AGENT_DEFAULT} has been deprecated. Use \$AGENT_RUBY instead." 1>&2
  AGENT_RUBY="${process_bin}"
fi

if [ -n "${PIDFILE}" ]; then
  echo "Warning: Declaring \$PIDFILE in ${AGENT_DEFAULT} has been deprecated. Use \$AGENT_PIDFILE instead." 1>&2
  AGENT_PID_FILE="${PIDFILE}"
fi

if [ -n "${DAEMON_ARGS}" ]; then
  START_STOP_DAEMON_ARGS=""
  parse_daemon_args() {
    while [ -n "$1" ]; do
      case "$1" in
      "--user="?* )
        echo "Warning: Declaring --user in \$DAEMON_ARGS has been deprecated. Use \$AGENT_USER instead." 1>&2
        AGENT_USER="${1#*=}"
        ;;
      "--user" )
        echo "Warning: Declaring --user in \$DAEMON_ARGS has been deprecated. Use \$AGENT_USER instead." 1>&2
        shift 1
        AGENT_USER="$1"
        ;;
      * )
        START_STOP_DAEMON_ARGS="${START_STOP_DAEMON_ARGS} $1"
        ;;
      esac
      shift 1
    done
  }
  parse_daemon_args ${DAEMON_ARGS}
fi

if [ -n "${AGENT_ARGS}" ]; then
  ORIG_AGENT_ARGS="${AGENT_ARGS}"
  AGENT_ARGS=""
  parse_agent_args() {
    while [ -n "$1" ]; do
      case "$1" in
      "--group="?* )
        echo "Warning: Declaring --group in \$AGENT_ARGS has been deprecated. Use \$AGENT_GROUP instead." 1>&2
        AGENT_GROUP="${1#*=}"
        ;;
      "--group" )
        echo "Warning: Declaring --group in \$AGENT_ARGS has been deprecated. Use \$AGENT_GROUP instead." 1>&2
        shift 1
        AGENT_GROUP="$1"
        ;;
      "--user="?* )
        echo "Warning: Declaring --user in \$AGENT_ARGS has been deprecated. Use \$AGENT_USER instead." 1>&2
        AGENT_USER="${1#*=}"
        ;;
      "--user" )
        echo "Warning: Declaring --user in \$AGENT_ARGS has been deprecated. Use \$AGENT_USER instead." 1>&2
        shift 1
        AGENT_USER="$1"
        ;;
      * )
        AGENT_ARGS="${AGENT_ARGS} $1"
        ;;
      esac
      shift 1
    done
  }
  parse_agent_args ${ORIG_AGENT_ARGS}
fi

# Arguments to run the daemon with
AGENT_ARGS="${AGENT_ARGS:-${AGENT_BIN_FILE} --log ${AGENT_LOG_FILE} ${AGENT_OPTIONS}}"
START_STOP_DAEMON_ARGS="${START_STOP_DAEMON_ARGS}"

# Exit if the package is not installed
[ -x "${AGENT_RUBY}" ] || exit 0

# Source function library.
. /etc/init.d/functions

# Check log_* functions definitions existence.
if [ -f /lib/lsb/init-functions ]; then
  # Depend on lsb-base (>= 3.0-6) to use original implementation
  . /lib/lsb/init-functions
else
  killproc() {
    LSB=LSB-1.1 killproc $*
  }

  log_success_msg() {
    echo -n "$*"
    $MOVE_TO_COL
    echo -ne "[  OK  ]\r"
    echo
  }

  log_failure_msg() {
    echo -n "$*"
    $MOVE_TO_COL
    echo -ne "[FAILED]\r"
    echo
  }
fi

# Check the user
if [ -n "${AGENT_USER}" ]; then
  if ! getent passwd "${AGENT_USER}" > /dev/null 2>&1; then
    echo "$0: user for running ${AGENT_NAME} doesn't exist: ${AGENT_USER}" >&2
    exit 1
  fi
  mkdir -p "$(dirname "${AGENT_PID_FILE}")"
  chown -R "${AGENT_USER}" "$(dirname "${AGENT_PID_FILE}")"
  START_STOP_DAEMON_ARGS="${START_STOP_DAEMON_ARGS} --user ${AGENT_USER}"
fi

if [ -n "${AGENT_GROUP}" ]; then
  if ! getent group -s files "${AGENT_GROUP}" > /dev/null 2>&1; then
    echo "$0: group for running ${AGENT_NAME} doesn't exist: ${AGENT_GROUP}" >&2
    exit 1
  fi
  AGENT_ARGS="${AGENT_ARGS} --group ${AGENT_GROUP}"
fi

if [ -n "${AGENT_PID_FILE}" ]; then
  mkdir -p "$(dirname "${AGENT_PID_FILE}")"
  chown -R "${AGENT_USER}" "$(dirname "${AGENT_PID_FILE}")"
  AGENT_ARGS="${AGENT_ARGS} --daemon ${AGENT_PID_FILE}"
fi

# Use jemalloc to avoid memory fragmentation
if [ -f "${AGENT_HOME}/embedded/lib/libjemalloc.so" ]; then
  export LD_PRELOAD="${AGENT_HOME}/embedded/lib/libjemalloc.so"
fi

kill_by_file() {
  local sig="$1"
  shift 1
  local pid="$(cat "$@" 2>/dev/null || true)"
  if [ -n "${pid}" ]; then
    if /bin/kill "${sig}" "${pid}" 1>/dev/null 2>&1; then
      return 0
    else
      return 2
    fi
  else
    return 1
  fi
}

#
# Function that starts the daemon/service
#
do_start() {
  # Set Max number of file descriptors for the safety sake
  # see http://docs.fluentd.org/en/articles/before-install
  ulimit -n 65536 1>/dev/null 2>&1 || true
  local RETVAL=0
  daemon --pidfile="${AGENT_PID_FILE}" ${START_STOP_DAEMON_ARGS} "${AGENT_RUBY}" ${AGENT_ARGS} || RETVAL="$?"
  [ $RETVAL -eq 0 ] && touch "${AGENT_LOCK_FILE}"
  return $RETVAL
}

#
# Function that stops the daemon/service
#
do_stop() {
  # Return
  #   0 if daemon has been stopped
  #   1 if daemon was already stopped
  #   2 if daemon could not be stopped
  #   other if a failure occurred
  if [ -e "${AGENT_PID_FILE}" ]; then
    # Use own process termination instead of killproc because killproc can't wait SIGTERM
    if kill_by_file -TERM "${AGENT_PID_FILE}"; then
      local i
      for i in $(seq "${STOPTIMEOUT}"); do
        if kill_by_file -0 "${AGENT_PID_FILE}"; then
          sleep 1
        else
          break
        fi
      done
      if kill_by_file -0 "${AGENT_PID_FILE}"; then
        echo -n "Timeout error occurred trying to stop ${AGENT_NAME}..."
        return 2
      else
        rm -f "${AGENT_PID_FILE}"
        rm -f "${AGENT_LOCK_FILE}"
      fi
    else
      return 1
    fi
  else
    if kill_by_file -0 "${AGENT_PID_FILE}"; then
      killproc "${AGENT_PROG_NAME:-${AGENT_NAME}}"
      rm -f "${AGENT_PID_FILE}"
      rm -f "${AGENT_LOCK_FILE}"
    else
      return 1
    fi
  fi
}

#
# Function that sends a SIGHUP to the daemon/service
#
do_reload() {
  kill_by_file -HUP "${AGENT_PID_FILE}"
}

do_restart() {
  if ! do_configtest; then
    return 1
  fi
  local val=0
  do_stop || val="$?"
  case "${val}" in
  0 | 1 )
    if ! do_start; then
      return 1
    fi
    ;;
  * ) # Failed to stop
    return 1
    ;;
  esac
}

do_configtest() {
  eval "${AGENT_ARGS} ${START_STOP_DAEMON_ARGS} --dry-run -q"
}

RETVAL=0
case "$1" in
"start" )
  echo -n "Starting ${AGENT_NAME}: "
  do_start || RETVAL="$?"
  case "$RETVAL" in
  0 | 1 )
    log_success_msg "${AGENT_NAME}"
    ;;
  * )
    log_failure_msg "${AGENT_NAME}"
    exit 1
    ;;
  esac
  ;;
"stop" )
  echo -n "Stopping ${AGENT_NAME}: "
  do_stop || RETVAL="$?"
  case "$RETVAL" in
  0 )
    log_success_msg "${AGENT_NAME}"
    ;;
  * )
    log_failure_msg "${AGENT_NAME}"
    exit 1
    ;;
  esac
  ;;
"reload" )
  echo -n "Reloading ${AGENT_NAME}: "
  if ! do_configtest; then
    log_failure_msg "${AGENT_NAME}"
    exit 1
  fi
  if do_reload; then
    log_success_msg "${AGENT_NAME}"
  else
    log_failure_msg "${AGENT_NAME}"
    exit 1
  fi
  ;;
"restart" )
  echo -n "Restarting ${AGENT_NAME}: "
  if do_restart; then
    log_success_msg "${AGENT_NAME}"
  else
    log_failure_msg "${AGENT_NAME}"
    exit 1
  fi
  ;;
"status" )
  if kill_by_file -0 "${AGENT_PID_FILE}"; then
    log_success_msg "${AGENT_NAME} is running"
  else
    log_failure_msg "${AGENT_NAME} is not running"
    exit 1
  fi
  ;;
"condrestart" )
  if [ -f "${AGENT_LOCK_FILE}" ]; then
    echo -n "Restarting ${AGENT_NAME}: "
    if do_restart; then
      log_success_msg "${AGENT_NAME}"
    else
      log_failure_msg "${AGENT_NAME}"
      exit 1
    fi
  fi
  ;;
"configtest" )
  if do_configtest; then
    log_success_msg "${AGENT_NAME}"
  else
    log_failure_msg "${AGENT_NAME}"
    exit 1
  fi
  ;;
* )
  echo "Usage: $0 {start|stop|reload|restart|condrestart|status|configtest}" >&2
  exit 1
  ;;
esac