#!/bin/sh
#
# Description:  Manages a memcached server as an OCF High-Availability
#               resource under Heartbeat/LinuxHA control
#
# OCF parameters:
#  OCF_RESKEY_memcached   - Path to executable.
#  OCF_RESKEY_start_opt   - Startup options.
#  OCF_RESKEY_pid_file    - Path to PID file.
#  OCF_RESKEY_user        - Which user to run the server as.
#  OCF_RESKEY_port        - Which TCP port to listen on.
#  OCF_RESKEY_max_memory  - Maximum cache size in megabytes.
#  OCF_RESKEY_max_conns   - Maximum number of connections.
###############################################################################
# Initialization:

PROG=memcached

. /usr/lib64/heartbeat/ocf-shellfuncs

unset LC_ALL; export LC_ALL
unset LANGUAGE; export LANGUAGE

SH=/bin/bash

usage() {
    cat <<-! >&1
        usage: $0 start|stop|status|monitor|methods

        $0 manages a memcached server as an HA resource.

        The 'start' operation starts the server.
        The 'stop' operation stops the server.
        The 'status' operation reports whether the server is up.
        The 'monitor' operation reports whether the server is running.
        The 'methods' operation reports on the methods $0 supports.
!
  return $OCF_ERR_ARGS
}

meta_data() {
        sed "s/__PROG__/$PROG/g" <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="__PROG__">
  <version>1.0</version>
  
  <longdesc lang="en">
    Resource script for __PROG__. It manages a server as an HA resource.
  </longdesc>
  <shortdesc lang="en">__PROG__ resource agent</shortdesc>
  
  <parameters>
    <parameter name="__PROG__" unique="0" required="0">
      <longdesc lang="en">
        Path to __PROG__ command.
      </longdesc>
      <shortdesc lang="en">__PROG__</shortdesc>
      <content type="string" default="/usr/local/fbprojects/__PROG__/bin/__PROG__" />
    </parameter>
    <parameter name="start_opt" unique="0" required="0">
      <longdesc lang="en">
        Start options. Do not include the -c, -m, -p or -P
	options here; there are specific settings for those.
      </longdesc>
      <shortdesc lang="en">start_opt</shortdesc>
      <content type="string" default="" />
    </parameter>
    <parameter name="port" unique="0" required="0">
      <longdesc lang="en">
        Which TCP port to listen on.
      </longdesc>
      <shortdesc lang="en">Port number</shortdesc>
      <content type="integer" default="11000" />
    </parameter>
    <parameter name="max_memory" unique="0" required="0">
      <longdesc lang="en">
        Amount of memory to use for cache, in megabytes.
      </longdesc>
      <shortdesc lang="en">Max Memory</shortdesc>
      <content type="integer" default="12288" />
    </parameter>
    <parameter name="max_conns" unique="0" required="0">
      <longdesc lang="en">
        Maximum number of connections allowed.
      </longdesc>
      <shortdesc lang="en">Max Connections</shortdesc>
      <content type="integer" default="1048576" />
    </parameter>
    <parameter name="pid_file" unique="0" required="0">
      <longdesc lang="en">
        Path to PID file.
      </longdesc>
      <shortdesc lang="en">PID File</shortdesc>
      <content type="string" default="/tmp/.memcached.pid.PORTNUMBER" />
    </parameter>
    <parameter name="user" unique="0" required="0">
      <longdesc lang="en">
        Which user to run the server as.
      </longdesc>
      <shortdesc lang="en">User</shortdesc>
      <content type="string" default="nobody" />
    </parameter>
  </parameters>
  
  <actions>
    <action name="start" timeout="120" />
    <action name="stop" timeout="120" />
    <action name="status" timeout="60" />
    <action name="monitor" depth="0" timeout="30" interval="30" start-delay="10" />
    <action name="meta-data" timeout="5" />
    <action name="methods" timeout="5" />
  </actions>
</resource-agent>
END
}


#
#       Run the given command in the Resource owner environment...
#
runasowner() {
    su $AS_USER -c ". ~${AS_USER}/.bash_profile; $*"
}

#
# methods: What methods/operations do we support?
#

prog_methods() {
  echo start
  echo stop
  echo status
  echo monitor
  echo methods
}


#prog_start: Starts the server
prog_start() {
    if prog_status
    then
        ocf_log info "$PROG is already running."
        return $OCF_SUCCESS
    fi

    if [ -x $EXECUTABLE ]
    then
	COMMANDLINE="$EXECUTABLE -d $START_OPT"
	if [ -n "$MAX_MEMORY" ]; then
		COMMANDLINE="$COMMANDLINE -m $MAX_MEMORY"
	fi
	if [ -n "$MAX_CONNS" ]; then
		COMMANDLINE="$COMMANDLINE -c $MAX_CONNS"
	fi
	if [ -n "$PORT" ]; then
		COMMANDLINE="$COMMANDLINE -p $PORT -U $PORT"
	fi
	if [ -n "$PID_FILE" ]; then
		COMMANDLINE="$COMMANDLINE -P $PID_FILE"
	fi
	if [ -n "$AS_USER" ]; then
		COMMANDLINE="$COMMANDLINE -u $AS_USER"
	fi
        echo $COMMANDLINE
        if $COMMANDLINE > /dev/null 2>&1
        then
           # Probably started.....
            ocf_log info "$PROG started."
        else
            ocf_log err "Can't start $PROG."
	    return $OCF_ERR_GENERIC
        fi
    else
        ocf_log err "$EXECUTABLE not found!"
        return $OCF_ERR_GENERIC
    fi
        
    if ! prog_status
    then
        sleep 5
        if ! prog_status
        then    
            echo "ERROR: $PROG is not running!"
            return $OCF_ERR_GENERIC
        fi
    fi

    return $OCF_SUCCESS
}

#prog_stop: Stops the server
prog_stop() {
    if ! prog_status
    then
        #Already stopped
        return $OCF_SUCCESS
    fi

    if [ ! -f $PID_FILE ]; then
        echo "ERROR: no PID file found"
        return $OCF_ERR_GENERIC
    fi

    kill `cat $PID_FILE`

    if prog_status
    then
        sleep 1
	kill -9 `cat $PID_FILE`
        if prog_status
        then
            echo "ERROR: server not terminating!"
	    return $OCF_ERR_GENERIC
        fi
    fi

    rm -f $PID_FILE
    return $OCF_SUCCESS
}

#
# prog_status: Is the server up?
#

prog_status() {
    STATS="`send_command stats`"
    case "$STATS" in
    STAT*)
    	return $OCF_SUCCESS
	;;
    "")
    	return $OCF_NOT_RUNNING
	;;
    *)
    	return $OCF_ERR_GENERIC
    esac
}


#
# sends a command to the server
#
send_command() {
    echo "`(echo "$1"; echo quit) | nc localhost $PORT`"
}

#
# prog_monitor
#

prog_monitor() {
    if ! prog_status
    then
        ocf_log info "$PROG is down"
        return $OCF_NOT_RUNNING
    fi
    
    return $OCF_SUCCESS
}

#
#   'main' starts here...
#


if [ $# -ne 1 ]
then
    usage
    exit 1
fi

US=`id -u -n`

if [ $US != root ]
then
    ocf_log err "$0 must be run as root"
    exit 1
fi

EXECUTABLE=${OCF_RESKEY_memcached:-/usr/local/fbprojects/$PROG/bin/$PROG}
START_OPT=${OCF_RESKEY_start_opt}
PORT=${OCF_RESKEY_port:-11000}
AS_USER=${OCF_RESKEY_user:-nobody}
MAX_MEMORY=${OCF_RESKEY_max_memory:-12288}
MAX_CONNS=${OCF_RESKEY_max_conns:-1048576}
PID_FILE=${OCF_RESKEY_pid_file:-/tmp/.memcached.pid.$PORT}

if [ ! -x $EXECUTABLE ]
then
    ocf_log err "Can't run $EXECUTABLE"
    exit $OCF_ERR_GENERIC
fi

# What kind of method was invoked?
case "$1" in
    start)      prog_start               
                exit $?;;

    stop)       prog_stop
                exit $?;;

    status)     if prog_status
                then
                    ocf_log info "$PROG is up"
                    exit $OCF_SUCCESS
                else
                    ocf_log info "$PROG is down"
                    exit $OCF_NOT_RUNNING
                fi
                exit $?;;

    monitor)    prog_monitor
                exit $?;;

    methods)    prog_methods
                exit $?;;
                
    meta_data)  meta_data
                exit $OCF_SUCCESS;;
esac

usage