#!/bin/bash
#
# priority: 850
#
# Manage settings for the Zabbix installtion and 
#	other monitor-related things
#
# Stephen Soltesz <soltesz@cs.princeton.edu>
# Copyright (C) 2008 The Trustees of Princeton University
#
# $Id$
#

# Source function library and configuration
. /etc/plc.d/functions
. /etc/planetlab/plc_config
local_config=/etc/planetlab/configs/site.xml

# Be verbose
set -x

# Default locations
PGDATA=/var/lib/pgsql/data
postgresql_conf=$PGDATA/postgresql.conf
pghba_conf=$PGDATA/pg_hba.conf

# Export so that we do not have to specify -p to psql invocations
export PGPORT=$PLC_DB_PORT


# TODO:
##   setup database
###    import schema & data
###    tweak values
###    add zabbix to pg_hba.conf
##   setup zabbix.conf.php 
##   
ZABBIX_DB_USER="zabbixuser"
ZABBIX_DB_NAME="zabbix"

function check_user_and_db()
{
    CREATED=
    # confirm user is present or create it
    user_present=$( psql -U postgres -c "select * from pg_user;" -d template1 | grep $ZABBIX_DB_USER )
    if [ -z $user_present ] ; then 
        createuser --no-superuser --no-createdb --no-createrole --login --unencrypted --echo $ZABBIX_DB_USER -U postgres
		CREATED="true"
    fi
    
    # confirm database is present or create it
    db_present=$( psql -U postgres -c "select * from pg_database;" -d template1 | grep $ZABBIX_DB_NAME )
    if [ -z $db_present ] ; then
        createdb --owner=$ZABBIX_DB_USER $ZABBIX_DB_NAME -U postgres
		CREATED="true"
    fi

    # Create/update the unprivileged database user and password
    if [ -z "$PLC_MONITOR_DBPASSWORD" ] ; then
        # Zabbix doesn't like plain uuidgen passwords
        PLC_MONITOR_DBPASSWORD=$( uuidgen | md5sum - | awk '{print $1}' )
        plc-config --category=plc_monitor --variable=dbpassword --value="$PLC_MONITOR_DBPASSWORD" --save=$local_config $local_config
        service plc reload
		CREATED="true"
    fi
    if [ -n "$CREATED" ] ; then
        psql -d template1 -U postgres -c "ALTER USER $ZABBIX_DB_USER WITH PASSWORD '$PLC_MONITOR_DBPASSWORD';"
    fi
}

function if_present_load ()
{
    file=$1
    if [ -f $file ] ; then
        psql -d $ZABBIX_DB_NAME -U $ZABBIX_DB_USER < $file
    fi
}

function check_schema_and_data() 
{
    schema_present=$( psql -U $ZABBIX_DB_USER $ZABBIX_DB_NAME -c "\d;" < /dev/null | grep hosts )
    if [ -z $schema_present ] ; then
        echo "... initial import can take SEVERAL minutes. please wait ..."
        if_present_load "/usr/local/zabbix/misc/create/schema/postgresql.sql"
        if_present_load "/usr/local/zabbix/misc/create/data/data.sql"
        if_present_load "/usr/local/zabbix/misc/create/data/images_pgsql.sql"
	## TODO: update ZABBIX Server entry, "update hosts set status=0, host='MyPLC Server' where hostid=10017"
    fi
}


case "$1" in
    start)
	if [ "$PLC_MONITOR_ENABLED" != "1" ] ; then
	    exit 0
	fi
	MESSAGE=$"Bootstrap Monitoring"
	dialog "$MESSAGE"

	#### SETUP ACCESS to this user and database
	mkdir -p /var/lib/pgsql/data/pg_hba.conf.d
	ZABCONF=/var/lib/pgsql/data/pg_hba.conf.d/zabbix.conf
	if [ ! -f $ZABCONF ] ; then
		echo "host $ZABBIX_DB_NAME $ZABBIX_DB_USER 127.0.0.1/32 password"   > $ZAB
		echo "host $ZABBIX_DB_NAME $ZABBIX_DB_USER $PLC_MONITOR_IP/32 password" >> $ZAB
	fi

	# NOTE: restart db to enable access by users granted above.
	service plc restart posgresql

	check_user_and_db 
	check_schema_and_data

        # UPDATE /etc/zabbix/*.conf
	ZABBIXCFG=/etc/zabbix
	TMP_FILE=`mktemp /tmp/zbxtmpXXXXXX`
	# TODO:  How to know if I need to restart the services?

	if [ -f ${ZABBIXCFG}/zabbix_server.conf ] ; then
		sed -e "s/#DBHost=.*/DBHost=$PLC_MONITOR_HOST/g" \
		    -e "s#DBName=.*#DBName=$ZABBIX_DB_NAME#g" \
		    -e "s#DBUser=.*#DBUser=$ZABBIX_DB_USER#g" \
		    -e "s#DBPassword=.*#DBPassword=$PLC_MONITOR_DBPASSWORD#g" \
		    ${ZABBIXCFG}/zabbix_server.conf > $TMP_FILE
		cat $TMP_FILE > ${ZABBIXCFG}/zabbix_server.conf
	fi
	if [ -f ${ZABBIXCFG}/zabbix_agentd.conf ] ; then
		HOST=`hostname`
		sed -e "s#Server=.*#Server=$PLC_MONITOR_HOST#g" \
		    -e "s#Hostname=.*#Hostname=$HOST#g" \
		    ${ZABBIXCFG}/zabbix_agentd.conf > $TMP_FILE
		cat $TMP_FILE > ${ZABBIXCFG}/zabbix_agentd.conf 
	fi
	service zabbix_server start
	service zabbix_agentd start

	# SETUP zabbix gui configuration
	ZABBIX_WEB_CFG=/var/www/html/zabbix/conf/zabbix.conf.php 
	if [ ! -f $ZABBIX_WEB_CFG ] ; then
		touch  $ZABBIX_WEB_CFG
		cat <<EOF > $ZABBIX_WEB_CFG
<?php
global \$DB;

\$DB["TYPE"]		= "POSTGRESQL";
\$DB["SERVER"]		= "localhost";
\$DB["PORT"]		= "0";
\$DB["DATABASE"]		= "$ZABBIX_DB_NAME";
\$DB["USER"]		= "$ZABBIX_DB_USER";
\$DB["PASSWORD"]		= "$PLC_MONITOR_DBPASSWORD";
\$ZBX_SERVER		= "$PLC_MONITOR_HOST";
\$ZBX_SERVER_PORT	= "10051";
\$IMAGE_FORMAT_DEFAULT	= IMAGE_FORMAT_PNG;
?>
EOF
		chmod 644 $ZABBIX_WEB_CFG
	fi

	result "$MESSAGE"
	;;

    stop)
	MESSAGE=$"Stopping Monitor"
	dialog "$MESSAGE"

	service zabbix_server stop
	service zabbix_agentd stop
	# TODO: is there anything to stop?
	result "$MESSAGE"
	;;
esac

exit $ERRORS