#!/bin/sh
#
# Description:	Manages a PostrgreSQL Server as an OCF High-Availability
#		resource under Heartbeat/LinuxHA control
#
#
# Author:	Serge Dubrouski (sergeyfd@gmail.com)
# Copyright 2006 Serge Dubrouski <sergeyfd@gmail.com>
# License:	GNU General Public License (GPL)
#
# OCF parameters:
#  OCF_RESKEY_pgctl  - Path to pg_ctl. Default /usr/bin/pg_ctl
#  OCF_RESKET_start_opt - Startup options. Default ""
#  OCF_RESKEY_psql   - Path to psql. Defauilt is /usr/bin/psql
#  OCF_RESKEY_pgdata - PGDATA directory. Default is /var/lib/pgsql/data
#  OCF_RESKEY_pgdba  - userID that manages DB. Default is postgres
#  OCF_RESKEY_pgdb   - database to monitor. Default is template1
###############################################################################
# Initialization:

. @hb_libdir@/ocf-shellfuncs

unset LC_ALL; export LC_ALL
unset LANGUAGE; export LANGUAGE

SH=@SHELL@

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

	$0 manages a PostgreSQL Server as an HA resource.

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

meta_data() {
	cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="pgsql">
<version>1.0</version>

<longdesc lang="en">
Resource script for PostgreSQL. It manages a PostgreSQL as an HA resource.
</longdesc>
<shortdesc lang="en">pgsql resource agent</shortdesc>

<parameters>
<parameter name="pgctl" unique="0" required="0">
<longdesc lang="en">
Path to pg_ctl command.
</longdesc>
<shortdesc lang="en">pgctl</shortdesc>
<content type="string" default="/usr/bin/pgctl" />
</parameter>
<parameter name="start_opt" unique="0" required="0">
<longdesc lang="en">
Start options. "-i -p 5432" for example.
</longdesc>
<shortdesc lang="en">start_opt</shortdesc>
<content type="string" default="" />
</parameter>
<parameter name="psql" unique="0" required="0">
<longdesc lang="en">
Path to psql command.
</longdesc>
<shortdesc lang="en">psql</shortdesc>
<content type="string" default="/usr/bin/psql" />
</parameter>
<parameter name="pgdata" unique="0" required="0">
<longdesc lang="en">
Path PostgreSQL data directory.
</longdesc>
<shortdesc lang="en">pgdata</shortdesc>
<content type="string" default="/var/lib/pgsql/data" />
</parameter>
<parameter name="pgdba" unique="0" required="0">
<longdesc lang="en">
User that owns PostgreSQL.
</longdesc>
<shortdesc lang="en">pgdba</shortdesc>
<content type="string" default="postgres" />
</parameter>
<parameter name="pgdb" unique="0" required="0">
<longdesc lang="en">
Database that will be used for monitoring.
</longdesc>
<shortdesc lang="en">pgdb</shortdesc>
<content type="string" default="template1" />
</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 $PGDBA -c ". ~${PGDBA}/.bash_profile; $*"
}

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

pgsql_methods() {
  cat <<-!
	start
	stop
	status
	monitor
	methods	
	!
}


#pgsql_start: Starts PostgreSQL
pgsql_start() {
    if pgsql_status
    then
        ocf_log info "PostgreSQL is already running. PID=`cat $PIDFILE`"
        return $OCF_SUCCESS
    fi
    
    if [ -x $PGCTL ]
    then
        # Check if we need to create a log file
        [ ! -f /var/log/pgsql.log ] && touch /var/log/pgsql.log
        # Set the right ownership

	if runasowner "$PGCTL -D $PGDATA -l /var/log/pgsql.log -o "\'$STARTOPT\'" start > /dev/null 2>&1"
	then
	   # Probably started.....
            ocf_log info "PostgreSQL start command sent."
	else
	    ocf_log err "Can't start PostgreSQL."; return $OCF_ERR_GENERIC
	fi
    else
	ocf_log err "$PGCTL not found!"
	return $OCF_ERR_GENERIC
    fi
	
    if ! pgsql_status
    then
	sleep 5
	if ! pgsql_status
	then	
	    echo "ERROR: PostgreSQL is not running!"
            return $OCF_ERR_GENERIC
	fi
    fi

    return $OCF_SUCCESS
}

#pgsql_stop: Stop PostgreSQL	
pgsql_stop() {
    if ! pgsql_status
    then
        #Already stopped
        return $OCF_SUCCESS
    fi
    
    # Stop PostgreSQL do not wait for clients to disconnect
    runasowner "$PGCTL -D $PGDATA stop -m fast > /dev/null 2>&1"

    if pgsql_status
    then
       #PostgreSQL is still up. Use another shutdown mode.
       runasowner "$PGCTL -D $PGDATA stop -m immediate > /dev/null 2>&1"
    fi

    return $OCF_SUCCESS
}

#
# pgsql_status: is PostgreSQL up?
#

pgsql_status() {
    if [ -f $PIDFILE  ]
    then
        PID=`head -n 1 $PIDFILE`
        process_running $PID && [ `ps -p $PID | grep postmaster | wc -l` -eq 1 ]
    else
        : No pid file
        false
    fi
}


#
# return TRUE if a process with given PID is running
#
process_running() {
    kill -0 "$1" >/dev/null 2>&1
}

#
# pgsql_monitor
#

pgsql_monitor() {
    if ! pgsql_status
    then
	ocf_log info "PostgreSQL is down"
	return $OCF_NOT_RUNNING
    fi
    
    $PSQL -U $PGDBA $PGDB -c 'select now();' >/dev/null 2>&1
    
    if [ $? -ne  0 ]
    then
	ocf_log err "PostgreSQL $PGDB isn't running"
	return $OCF_ERR_GENERIC
    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

PGCTL=${OCF_RESKEY_pgctl:-/usr/bin/pg_ctl}
STARTOPT=${OCF_RESKEY_start_opt:-""}
PSQL=${OCF_RESKEY_psql:-/usr/bin/psql}
PGDATA=${OCF_RESKEY_pgdata:-/var/lib/pgctl/data}
PGDBA=${OCF_RESKEY_pgdba:-postgres}
PGDB=${OCF_RESKEY_pgdb:-template1}
PIDFILE=${PGDATA}/postmaster.pid

case "$1" in
    methods)    pgsql_methods
                exit $?;;
		
    meta_data)  meta_data
                exit $OCF_SUCCESS;;
esac

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

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

    stop)       pgsql_stop
                exit $?;;

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

    monitor)    pgsql_monitor
                exit $?;;
esac

usage