#!/bin/sh
#
# postgresql-setup	Initialization and upgrade operations for PostgreSQL

# PGVERSION is the full package version, e.g., 9.0.2
# Note: the specfile inserts the correct value during package build
PGVERSION=xxxx
# PGENGINE is the directory containing the postmaster executable
# Note: the specfile inserts the correct value during package build
PGENGINE=xxxx
# PREVMAJORVERSION is the previous major version, e.g., 8.4, for upgrades
# Note: the specfile inserts the correct value during package build
PREVMAJORVERSION=xxxx
# PREVPGENGINE is the directory containing the previous postmaster executable
# Note: the specfile inserts the correct value during package build
PREVPGENGINE=xxxx

# Absorb configuration settings from the specified systemd service file,
# or the default "postgresql" service if not specified
SERVICE_NAME="$2"
if [ x"$SERVICE_NAME" = x ]
then
    SERVICE_NAME=postgresql
fi

# this parsing technique fails for PGDATA pathnames containing spaces,
# but there's not much I can do about it given systemctl's output format...
PGDATA=`systemctl show -p Environment "${SERVICE_NAME}.service" |
  sed 's/^Environment=//' | tr ' ' '\n' |
  sed -n 's/^PGDATA=//p' | tail -n 1`

if [ x"$PGDATA" = x ]
then
    echo "failed to find PGDATA setting in ${SERVICE_NAME}.service"
    exit 1
fi

PGPORT=`systemctl show -p Environment "${SERVICE_NAME}.service" |
  sed 's/^Environment=//' | tr ' ' '\n' |
  sed -n 's/^PGPORT=//p' | tail -n 1`

if [ x"$PGPORT" = x ]
then
    echo "failed to find PGPORT setting in ${SERVICE_NAME}.service"
    exit 1
fi

# Log file for initdb
PGLOG=/var/lib/pgsql/initdb.log

# Log file for pg_upgrade
PGUPLOG=/var/lib/pgsql/pgupgrade.log

export PGDATA
export PGPORT

# For SELinux we need to use 'runuser' not 'su'
if [ -x /sbin/runuser ]
then
    SU=runuser
else
    SU=su
fi

script_result=0

# code shared between initdb and upgrade actions
perform_initdb(){
	if [ ! -e "$PGDATA" ]
	then
		mkdir "$PGDATA" || return 1
		chown postgres:postgres "$PGDATA"
		chmod go-rwx "$PGDATA"
	fi
	# Clean up SELinux tagging for PGDATA
	[ -x /sbin/restorecon ] && /sbin/restorecon "$PGDATA"

	# Create the initdb log file if needed
	if [ ! -e "$PGLOG" -a ! -h "$PGLOG" ]
	then
		touch "$PGLOG" || return 1
		chown postgres:postgres "$PGLOG"
		chmod go-rwx "$PGLOG"
		[ -x /sbin/restorecon ] && /sbin/restorecon "$PGLOG"
	fi

	# Initialize the database
	$SU -l postgres -c "$PGENGINE/initdb --pgdata='$PGDATA' --auth='ident'" >> "$PGLOG" 2>&1 < /dev/null

	# Create directory for postmaster log files
	mkdir "$PGDATA/pg_log"
	chown postgres:postgres "$PGDATA/pg_log"
	chmod go-rwx "$PGDATA/pg_log"
	[ -x /sbin/restorecon ] && /sbin/restorecon "$PGDATA/pg_log"

	if [ -f "$PGDATA/PG_VERSION" ]
	then
	    return 0
	fi
	return 1
}

initdb(){
    if [ -f "$PGDATA/PG_VERSION" ]
    then
	echo $"Data directory is not empty!"
	echo
	script_result=1
    else
	echo -n $"Initializing database ... "
	if perform_initdb
	then
	    echo $"OK"
	else
	    echo $"failed, see $PGLOG"
	    script_result=1
	fi
	echo
    fi
}

upgrade(){
    # must see previous version in PG_VERSION
    if [ ! -f "$PGDATA/PG_VERSION" -o \
	 x`cat "$PGDATA/PG_VERSION"` != x"$PREVMAJORVERSION" ]
    then
	echo
	echo $"Cannot upgrade because database is not of version $PREVMAJORVERSION."
	echo
	exit 1
    fi
    if [ ! -x "$PGENGINE/pg_upgrade" ]
    then
	echo
	echo $"Please install the postgresql-upgrade RPM."
	echo
	exit 5
    fi

    # Make sure service is stopped
    # Using service here makes it work both with systemd and other init systems
    service "$SERVICE_NAME" stop

    # Set up log file for pg_upgrade
    rm -f "$PGUPLOG"
    touch "$PGUPLOG" || exit 1
    chown postgres:postgres "$PGUPLOG"
    chmod go-rwx "$PGUPLOG"
    [ -x /sbin/restorecon ] && /sbin/restorecon "$PGUPLOG"

    # Move old DB to PGDATAOLD
    PGDATAOLD="${PGDATA}-old"
    rm -rf "$PGDATAOLD"
    mv "$PGDATA" "$PGDATAOLD" || exit 1

    echo -n $"Upgrading database: "

    # Create empty new-format database
    if perform_initdb
    then
	# Do the upgrade
	$SU -l postgres -c "$PGENGINE/pg_upgrade \
		'--old-bindir=$PREVPGENGINE' \
		'--new-bindir=$PGENGINE' \
		'--old-datadir=$PGDATAOLD' \
		'--new-datadir=$PGDATA' \
		--link \
		'--old-port=$PGPORT' '--new-port=$PGPORT' \
		--user=postgres" >> "$PGUPLOG" 2>&1 < /dev/null
	if [ $? -ne 0 ]
	then
	    # pg_upgrade failed
	    script_result=1
	fi
    else
	# initdb failed
	script_result=1
    fi

    if [ $script_result -eq 0 ]
    then
	    echo $"OK"
    else
	    # Clean up after failure
	    rm -rf "$PGDATA"
	    mv "$PGDATAOLD" "$PGDATA"

	    echo $"failed"
    fi
    echo
    echo $"See $PGUPLOG for details."
}

# See how we were called.
case "$1" in
  initdb)
	initdb
	;;
  upgrade)
	upgrade
	;;
  *)
	echo $"Usage: $0 {initdb|upgrade} [ service_name ]"
	exit 2
esac

exit $script_result