#!/bin/bash
# Copyright (C) 2017 AT&T Intellectual Property. All rights reserved. 
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this code except in compliance
# with the License. You may obtain a copy of the License
# at http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software  
# distributed under the License is distributed on an "AS IS" BASIS,  
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or  
# implied. See the License for the specific language governing  
# permissions and limitations under the License. 


# NAME
#	list_masters - loop through the nodes in the cluster, using pgwget to determine if any are a master. 

CDF=/opt/app/cdf
if [ -d /opt/app/postgresql-9.5.2 ]
then PGDIR=/opt/app/postgresql-9.5.2
elif [ -d /usr/lib/postgresql/9.6 ]
then PGDIR=/usr/lib/postgresql/9.6
elif [ -d /usr/lib/postgresql/9.5 ]
then PGDIR=/usr/lib/postgresql/9.5
else echo PostgreSQL bin directory not found 1>&2; exit 1
fi
PATH=$PGDIR/bin:$CDF/bin:/opt/app/pgaas/bin:$PATH

usage()
{
    exec 1>&2
    [ $# -gt 0 ] && echo "$@"
    echo "Usage: $0 [-r] [-v]"
    echo -e " -r          check /ro instead of /rw"
    echo -e " -v          verbose"
    exit 1
}

VERBOSE=false
CMD=rw
QUIET=--quiet
OUTPUT=-O/dev/null
while getopts rvQ c
do
    case "$c" in
	r ) CMD=ro ;;
	Q ) QUIET= OUTPUT= ;;
	v ) VERBOSE=: ;;
	\?) usage ;;
    esac
done
shift $(($OPTIND - 1))

# loop through the nodes in the cluster, using pgwget to determine if any are a master. Save in $@
for i in $(getpropvalue -n pgnodes | sed 's/|/ /g')
do
    $VERBOSE && echo "Checking $i"
    if pgwget $QUIET $OUTPUT http://$i:8000/$CMD
    then set -- "$@" $i
    fi
done

echo "$@"
case "$CMD" in
    rw )
        case $# in
	    1 ) exit 0 ;;	# one master exists and is running
	    0 ) exit 1 ;;	# no masters exist
	    * ) exit 2 ;;	# more than one master exist
	esac
	;;
    ro )
        case $# in
	    0 ) exit 1 ;;	# no masters exist
	    * ) exit 0 ;;	# one or more masters+secondaries exist
	esac
	;;
esac