#!/bin/sh
#
# Description:  Manages a PostgreSQL Server as an OCF High-Availability
#               resource
#
# Authors:      Serge Dubrouski (sergeyfd@gmail.com) -- original RA
#               Florian Haas (florian@linbit.com) -- makeover
#
# Copyright:    2006-2010 Serge Dubrouski <sergeyfd@gmail.com>
#                         and other Linux-HA contributors
# License:      GNU General Public License (GPL)
#
###############################################################################
# Initialization:

: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/resource.d/heartbeat}
. ${OCF_FUNCTIONS_DIR}/.ocf-shellfuncs

# Defaults
OCF_RESKEY_pgctl_default=/usr/bin/pg_ctl
OCF_RESKEY_psql_default=/usr/bin/psql
OCF_RESKEY_pgdata_default=/var/lib/pgsql/data
OCF_RESKEY_pgdba_default=postgres
OCF_RESKEY_pghost_default=""
OCF_RESKEY_pgport_default=5432
OCF_RESKEY_config_default=""
OCF_RESKEY_start_opt_default=""
OCF_RESKEY_pgdb_default=template1
OCF_RESKEY_logfile_default=/dev/null
OCF_RESKEY_stop_escalate_default=30

: ${OCF_RESKEY_pgctl=${OCF_RESKEY_pgctl_default}}
: ${OCF_RESKEY_psql=${OCF_RESKEY_psql_default}}
: ${OCF_RESKEY_pgdata=${OCF_RESKEY_pgdata_default}}
: ${OCF_RESKEY_pgdba=${OCF_RESKEY_pgdba_default}}
: ${OCF_RESKEY_pghost=${OCF_RESKEY_pghost_default}}
: ${OCF_RESKEY_pgport=${OCF_RESKEY_pgport_default}}
: ${OCF_RESKEY_config=${OCF_RESKEY_config_default}}
: ${OCF_RESKEY_start_opt=${OCF_RESKEY_start_opt_default}}
: ${OCF_RESKEY_pgdb=${OCF_RESKEY_pgdb_default}}
: ${OCF_RESKEY_logfile=${OCF_RESKEY_logfile_default}}
: ${OCF_RESKEY_stop_escalate=${OCF_RESKEY_stop_escalate_default}}

usage() {
    cat <<EOF
	usage: $0 start|stop|status|monitor|meta-data|validate-all|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 'validate-all' operation reports whether the parameters are valid.
        The 'methods' operation reports on the methods $0 supports.
EOF
  return $OCF_ERR_ARGS
}

meta_data() {
	cat <<EOF
<?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">Manages a PostgreSQL database instance</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="${OCF_RESKEY_pgctl_default}" />
</parameter>

<parameter name="start_opt" unique="0" required="0">
<longdesc lang="en">
Start options (-o start_opt in pg_ctl). "-i -p 5432" for example.
</longdesc>
<shortdesc lang="en">start_opt</shortdesc>
<content type="string" default="${OCF_RESKEY_start_opt_default}" />

</parameter>
<parameter name="ctl_opt" unique="0" required="0">
<longdesc lang="en">
Additional pg_ctl options (-w, -W etc..).
</longdesc>
<shortdesc lang="en">ctl_opt</shortdesc>
<content type="string" default="${OCF_RESKEY_ctl_opt_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="${OCF_RESKEY_psql_default}" />
</parameter>

<parameter name="pgdata" unique="0" required="0">
<longdesc lang="en">
Path to PostgreSQL data directory.
</longdesc>
<shortdesc lang="en">pgdata</shortdesc>
<content type="string" default="${OCF_RESKEY_pgdata_default}" />
</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="${OCF_RESKEY_pgdba_default}" />
</parameter>

<parameter name="pghost" unique="0" required="0">
<longdesc lang="en">
Hostname/IP address where PostgreSQL is listening
</longdesc>
<shortdesc lang="en">pghost</shortdesc>
<content type="string" default="${OCF_RESKEY_pghost_default}" />
</parameter>

<parameter name="pgport" unique="0" required="0">
<longdesc lang="en">
Port where PostgreSQL is listening
</longdesc>
<shortdesc lang="en">pgport</shortdesc>
<content type="integer" default="${OCF_RESKEY_pgport_default}" />
</parameter>

<parameter name="config" unique="0" required="0">
<longdesc lang="en">
Path to the PostgreSQL configuration file for the instance
</longdesc>
<shortdesc lang="en">Configuration file</shortdesc>
<content type="integer" default="${OCF_RESKEY_config_default}" />
</parameter>

<parameter name="start_opt" unique="0" required="0">
<longdesc lang="en">
Additional options passed to the PostgreSQL server daemon.
</longdesc>
<shortdesc lang="en">Additional PostgreSQL server options</shortdesc>
<content type="string" default="${OCF_RESKEY_start_opt_default}" />
</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="${OCF_RESKEY_pgdb_default}" />
</parameter>

<parameter name="logfile" unique="0" required="0">
<longdesc lang="en">
Path to PostgreSQL server log output file.
</longdesc>
<shortdesc lang="en">logfile</shortdesc>
<content type="string" default="${OCF_RESKEY_logfile_default}" />
</parameter>

<parameter name="stop_escalate" unique="0" required="0">
<longdesc lang="en">
Number of shutdown retries (using -m fast) before resorting to -m immediate
</longdesc>
<shortdesc lang="en">stop escalation</shortdesc>
<content type="integer" default="${OCF_RESKEY_stop_escalation}" />
</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"/>
<action name="meta-data" timeout="5" />
<action name="validate-all" timeout="5" />
<action name="methods" timeout="5" />
</actions>
</resource-agent>
EOF
}


#
#	Run the given command in the Resource owner environment...
#
runasowner() {
    ocf_run su $OCF_RESKEY_pgdba -c "$*"
}

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

pgsql_methods() {
  cat <<EOF
	start
	stop
	status
	monitor
	methods
	meta-data
	validate-all
EOF
}


#pgsql_start: Starts PostgreSQL
pgsql_start() {
    local pgctl_options
    local postgres_options

    if pgsql_status; then
        ocf_log info "PostgreSQL is already running. PID=`cat $PIDFILE`"
        return $OCF_SUCCESS
    fi

    # Remove postmaster.pid if it exists
    rm -f $PIDFILE

    # Remove backup_label if it exists
    if [ -f $BACKUPLABEL ]; then
	ocf_log info "Removing $BACKUPLABEL. The previous backup might have failed."
	rm -f $BACKUPLABEL
    fi

    # Check if we need to create a log file
    if ! check_log_file $OCF_RESKEY_logfile
    then
        ocf_log err "PostgreSQL can't write to the log file: $OCF_RESKEY_logfile"
	return $OCF_ERR_GENERIC
    fi

    # Set options passed to pg_ctl
    pgctl_options="$OCF_RESKEY_ctl_opt -D $OCF_RESKEY_pgdata -l $OCF_RESKEY_logfile"

    # Set options passed to the PostgreSQL server process
    postgres_options=""
    if [ -n "$OCF_RESKEY_config" ]; then
	postgres_options="$postgres_options -c config_file=${OCF_RESKEY_config}"
    fi
    if [ -n "$OCF_RESKEY_pghost" ]; then
	postgres_options="$postgres_options -h $OCF_RESKEY_pghost"
    fi
    if [ -n "$OCF_RESKEY_start_opt" ]; then
	postgres_options="$postgres_options $OCF_RESKEY_start_opt"
    fi

    # Tack pass-through options onto pg_ctl options
    if [ -n "$postgres_options" ]; then
	pgctl_options="$pgctl_options -o '$postgres_options'"
    fi

    # Invoke pg_ctl
    runasowner "$OCF_RESKEY_pgctl $pgctl_options start"

    if [ $? -eq 0 ]; then
	# Probably started.....
        ocf_log info "PostgreSQL start command sent."
    else
	ocf_log err "Can't start PostgreSQL."
        return $OCF_ERR_GENERIC
    fi

    while :
    do
        pgsql_monitor warn
        rc=$?
        if [ $rc -eq 0 ]; then
            break;
        fi
        sleep 1
	ocf_log debug "PostgreSQL still hasn't started yet. Waiting..."
    done
    ocf_log info "PostgreSQL is started."

    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 "$OCF_RESKEY_pgctl -D $OCF_RESKEY_pgdata stop -m fast"

    # stop waiting
    count=0
    while [ $count -lt $OCF_RESKEY_stop_escalate ]
    do
        if ! pgsql_status
        then
            #PostgreSQL stopped
            break;
        fi
        count=`expr $count + 1`
        sleep 1
    done

    if pgsql_status
    then
       #PostgreSQL is still up. Use another shutdown mode.
       ocf_log info "PostgreSQL failed to stop after ${OCF_RESKEY_stop_escalate}s using -m fast. Trying -m immediate..."
       runasowner "$OCF_RESKEY_pgctl -D $OCF_RESKEY_pgdata stop -m immediate"
    fi

    while :
    do
        pgsql_monitor
        rc=$?
        if [ $rc -eq $OCF_NOT_RUNNING ]; then
            # An unnecessary debug log is prevented.
            break;
        fi
	sleep 1
	ocf_log debug "PostgreSQL still hasn't stopped yet. Waiting..."
    done

    # Remove postmaster.pid if it exists
    rm -f $PIDFILE

    return $OCF_SUCCESS
}

#
# pgsql_status: is PostgreSQL up?
#

pgsql_status() {
     if [ -f $PIDFILE ]
     then
         PID=`head -n 1 $PIDFILE`
         kill -s 0 $PID >/dev/null 2>&1 && fuser $OCF_RESKEY_pgdata 2>&1 | grep $PID >/dev/null 2>&1
         return $?
     fi

     # No PID file
     false
}

#
# pgsql_monitor
#

pgsql_monitor() {
    local loglevel
    local psql_options

    # Set the log level of the error message
    loglevel=${1:-err}

    if ! pgsql_status
    then
	ocf_log info "PostgreSQL is down"
	return $OCF_NOT_RUNNING
    fi

    psql_options="-p $OCF_RESKEY_pgport -U $OCF_RESKEY_pgdba $OCF_RESKEY_pgdb"
    if [ -n "$OCF_RESKEY_pghost" ]; then
	psql_options="$psql_options -h $OCF_RESKEY_pghost"
    fi
    runasowner "$OCF_RESKEY_psql $psql_options -c 'select now();'"

    rc=$?
    if [ $rc -ne  0 ]; then
	ocf_log $loglevel "PostgreSQL $OCF_RESKEY_pgdb isn't running"
        if [ $rc -eq 1 ]; then
            ocf_log err "Fatal error (out of memory, file not found, etc.) occurred while executing the psql command."
        elif [ $rc -eq 2 ]; then
            ocf_log $loglevel "Connection error (connection to the server went bad and the session was not interactive) occurred while executing the psql command."
        elif [ $rc -eq 3 ]; then
            ocf_log err "Script error (the variable ON_ERROR_STOP was set) occurred while executing the psql command."
        fi
	return $OCF_ERR_GENERIC
    fi

    return $OCF_SUCCESS
}

# Validate most critical parameters
pgsql_validate_all() {
    check_binary $OCF_RESKEY_pgctl
    check_binary $OCF_RESKEY_psql

    return $OCF_SUCCESS
}


#
# Check if we need to create a log file
#

check_log_file() {
    if [ ! -f "$1" ]
    then
        touch $1 > /dev/null 2>&1
        chown $OCF_RESKEY_pgdba:$(getent passwd $OCF_RESKEY_pgdba | cut -d ":" -f 4) $1
    fi

    #Check if $OCF_RESKEY_pgdba can write to the log file
    if ! runasowner "test -w $1"
    then
        return 1
    fi

    return 0
}

#
#   'main' starts here...
#


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


PIDFILE=${OCF_RESKEY_pgdata}/postmaster.pid
BACKUPLABEL=${OCF_RESKEY_pgdata}/backup_label

case "$1" in
    methods)    pgsql_methods
                exit $?;;

    meta-data)  meta_data
                exit $OCF_SUCCESS;;

    validate-all) pgsql_validate_all
                exit $?;;
esac

if ! pgsql_validate_all
then
    case "$1" in
        stop)    exit $OCF_SUCCESS;;
        monitor) exit $OCF_NOT_RUNNING;;
        status)  exit $OCF_NOT_RUNNING;;
        *)       exit $OCF_ERR_INSTALLED;;
    esac
fi

US=`id -u -n`

if [ $US != root -a $US != $OCF_RESKEY_pgdba ]
then
    ocf_log err "$0 must be run as root or $OCF_RESKEY_pgdba"
    exit $OCF_ERR_GENERIC
fi

# What kind of method was invoked?
case "$1" in
    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;;

    monitor)    pgsql_monitor
                exit $?;;

    start)      pgsql_start
                exit $?;;

    stop)       pgsql_stop
                exit $?;;
    *)
                exit $OCF_ERR_UNIMPLEMENTED;;
esac
