#!/bin/sh
#
#
#	Rsyslog
#	Description: Manages a Rsyslog service as a stateful Rsyslog OCF resource
#	Master	-> Rsyslog runs as server and accepts syslog network packets
#	Slave	-> Rsyslog runs as client
#
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of version 2 of the GNU General Public License as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it would be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#
# Further, this software is distributed without any warranty that it is
# free of the rightful claim of any third person regarding infringement
# or the like.  Any license provided herein, whether implied or
# otherwise, applies only to this software file.  Patent licenses, if
# any, provided herein do not apply to combinations of this program with
# other software, or any other product whatsoever.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write the Free Software Foundation,
# Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
#
# Copyright (c) 2010 T-Systems GEI GmbH, Simon Jansen <simon.jansen@t-systems.com>
#                    All Rights Reserved.
#
#######################################################################
#
# OCF Parameters:
#	OCF_RESKEY_binfile		: Executable file
#	OCF_RESKEY_master_config	: Configuration file for master
#	OCF_RESKEY_slave_config		: Configuration file for slave
#	OCF_RESKEY_port			: UDP port Rsyslog is listening on
#	OCF_RESKEY_pidfile		: Process id file
#	OCF_RESKEY_further_params	: Further parameters
#	OCF_RESKEY_nmap_binfile		: Executable file of nmap
#
# Parameters with default values:	OCF_RESKEY_binfile,
#					OCF_RESKEY_master_config,
#					OCF_RESKEY_slave_config,
#					OCF_RESKEY_port,
#					OCF_RESKEY_pidfile,
#					OCF_RESKEY_further_params,
#					OCF_RESKEY_nmap_binfile
#
#######################################################################
# Initialization:

: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/resource.d/heartbeat}
. ${OCF_FUNCTIONS_DIR}/.ocf-shellfuncs
CRM_MASTER="${HA_SBIN_DIR}/crm_master -l reboot"

#######################################################################


#----------------------------------------------------------------------
# Definitions and default values
#----------------------------------------------------------------------
# Define default values for parameters
OCF_RESKEY_binfile_default="/usr/sbin/rsyslogd"
OCF_RESKEY_master_config_default="/etc/rsyslog_master.conf"
OCF_RESKEY_slave_config_default="/etc/rsyslog_slave.conf"
OCF_RESKEY_port_default="514"
OCF_RESKEY_pidfile_default="/var/run/rsyslogd.pid"
OCF_RESKEY_nmap_binfile_default="/usr/bin/nmap"

# Fill in defaults if no values are defined
: ${OCF_RESKEY_binfile=${OCF_RESKEY_binfile_default}}
: ${OCF_RESKEY_master_config=${OCF_RESKEY_master_config_default}}
: ${OCF_RESKEY_slave_config=${OCF_RESKEY_slave_config_default}}
: ${OCF_RESKEY_port=${OCF_RESKEY_port_default}}
: ${OCF_RESKEY_pidfile=${OCF_RESKEY_pidfile_default}}
: ${OCF_RESKEY_nmap_binfile=${OCF_RESKEY_nmap_binfile_default}}

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

<longdesc lang="en">
This is an OCF stateful resource agent to manage the Rsyslog service in a high-availability setup.
In the master role the node starts the service with the master config and in the slave role
with the slave config.
The agent monitors the service in the master role via nmap by checking the status of the port Rsyslog is listening on. 
So you have to install nmap to use this RA.
</longdesc>
<shortdesc lang="en">Manages a Rsyslog instance as a master/slave resource</shortdesc>

<parameters>
<parameter name="binfile" unique="0" required="0">
<longdesc lang="en">
This parameter defines the executable file of the Rsyslog service.
The default value is ${OCF_RESKEY_binfile_default}.
</longdesc>
<shortdesc lang="en">Executable file</shortdesc>
<content type="string" default="$OCF_RESKEY_binfile_default" />
</parameter>

<parameter name="master_config" unique="0" required="0">
<longdesc lang="en">
This parameter defines the configuration file of the Rsyslog service in the master role.
The default value is ${OCF_RESKEY_master_config_default}.
</longdesc>
<shortdesc lang="en">Master configuration file</shortdesc>
<content type="string" default="$OCF_RESKEY_master_config_default" />
</parameter>

<parameter name="slave_config" unique="0" required="0">
<longdesc lang="en">
This parameter defines the configuration file of the Rsyslog service in the slave role.
The default value is ${OCF_RESKEY_slave_config_default}.
</longdesc>
<shortdesc lang="en">Slave configuration file</shortdesc>
<content type="string" default="$OCF_RESKEY_slave_config_default" />
</parameter>

<parameter name="port" unique="0" required="0">
<longdesc lang="en">
This parameter defines the UDP port Rsyslog is listening on.
The port is defined in the configuration file. This value is only 
used to monitor the service via nmap.
The default value is ${OCF_RESKEY_port_default}.
</longdesc>
<shortdesc lang="en">UDP port Rsyslog is listening on</shortdesc>
<content type="string" default="$OCF_RESKEY_port_default" />
</parameter>

<parameter name="pidfile" unique="0" required="0">
<longdesc lang="en">
This parameter defines the process id file of the Rsyslog service.
The default value is ${OCF_RESKEY_pidfile_default}.
</longdesc>
<shortdesc lang="en">Process id file</shortdesc>
<content type="string" default="$OCF_RESKEY_pidfile_default" />
</parameter>

<parameter name="further_params" unique="0" required="0">
<longdesc lang="en">
This parameter defines additional parameters that are passed to the Rsyslog service
during the startup.
</longdesc>
<shortdesc lang="en">Further parameters</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="nmap_binfile" unique="0" required="0">
<longdesc lang="en">
This parameter defines the executable file of nmap.
The default value is ${OCF_RESKEY_nmap_binfile_default}.
</longdesc>
<shortdesc lang="en">Nmap executable file</shortdesc>
<content type="string" default="$OCF_RESKEY_nmap_binfile_default" />
</parameter>
</parameters>

<actions>
<action name="start"        timeout="120" />
<action name="stop"         timeout="120" />
<action name="monitor"      timeout="30" interval="10" depth="0" />
<action name="reload"       timeout="20" />
<action name="meta-data"    timeout="5" />
<action name="validate-all"   timeout="20" />
</actions>
</resource-agent>
END
}

#######################################################################

Rsyslog_usage() {
cat <<END
usage: $0 {start|stop|promote|demote|monitor|validate-all|meta-data}

$0 manages a Rsyslog instance as a master/slave resource.

The 'start' operation starts the Rsyslog service.
The 'stop' operation stops the Rsyslog service.
The 'promote' operation promotes the node to the master role.
The 'demote' operation demotes the node to the slave role.
The 'monitor' operation reports if the Rsyslog service seems to be working.
The 'validate-all' operation reports whether the parameters are valid.
The 'meta-data' operation shows the meta data message of this resource agent.
END
}

Rsyslog_start() {
	local rc
	local status
	local first_try=true

	rc=$OCF_ERR_GENERIC
	
	# Start Rsyslog as master 
	${OCF_RESKEY_binfile} -c4 -f ${OCF_RESKEY_slave_config} -i ${OCF_RESKEY_pidfile} \
	${OCF_RESKEY_further_params}

	# Keep trying to bring up Rsyslog service;
	# wait for the CRM to time us out if this fails
	while :; do
		Rsyslog_monitor
		status=$?
		case "$status" in
		$OCF_SUCCESS)
			ocf_log info "Rsyslog successfully started as slave."
			$CRM_MASTER -v 5
			return $OCF_SUCCESS
			;;
		$OCF_NOT_RUNNING)
			rc=$OCF_NOT_RUNNING
			;;
		$OCF_RUNNING_MASTER)
			ocf_log warn "Rsyslog already started as primary, demoting."
			Rsyslog_demote
		esac
		$first_try || sleep 1
		first_try=false
	done

	return $rc
}

Rsyslog_start_master() {
	local rc
	local status
	local first_try=true

	rc=$OCF_ERR_GENERIC
	
	# Start Rsyslog as master 
	${OCF_RESKEY_binfile} -c4 -f ${OCF_RESKEY_master_config} -i ${OCF_RESKEY_pidfile} \
	${OCF_RESKEY_further_params}
	
	# Keep trying to bring up Rsyslog service;
	# wait for the CRM to time us out if this fails
	while :; do
		Rsyslog_monitor
		status=$?
		case "$status" in
		$OCF_NOT_RUNNING)
			rc=$OCF_NOT_RUNNING
			;;
		$OCF_RUNNING_MASTER)
			ocf_log info "Rsyslog successfully started as master."
			$CRM_MASTER -v 10
			return $OCF_SUCCESS
		esac
		$first_try || sleep 1
		first_try=false
	done

	return $rc
}

Rsyslog_demote() {
	local status
	local first_try=true
	local retVal

	# Keep trying to demote Rsyslog;
	# wait for the CRM to time us out if this fails
	while :; do
		Rsyslog_monitor
		status=$?
		case "$status" in
		$OCF_SUCCESS)
			ocf_log info "Rsyslog successfully demoted."
			return $OCF_SUCCESS
			;;
		#$OCF_NOT_RUNNING)
		#	ocf_log error "Trying to promote Rsyslog but it was not started."
		#	return $OCF_ERR_GENERIC
		#	break
		#	;;
		$OCF_RUNNING_MASTER)
			Rsyslog_stop
			retVal=$?
			if [ $retVal = $OCF_SUCCESS ]; then
				Rsyslog_start
			else
				ocf_log error "Could not demote Rsyslog because the stop action failed."
				return $OCF_ERR_GENERIC
			fi
		esac
		$first_try || sleep 1
		first_try=false
	done

	return $OCF_ERR_GENERIC
}

Rsyslog_promote() {
	local rc
	local status
	local first_try=true
	local first_try

	rc=$OCF_ERR_GENERIC

	# Keep trying to ptomote Rsyslog;
	# wait for the CRM to time us out if this fails
	while :; do
		Rsyslog_monitor
		status=$?
		case "$status" in
		$OCF_SUCCESS)
			Rsyslog_stop
			retVal=$?
			if [ $retVal = $OCF_SUCCESS ]; then
				# Start Rsyslog as master
				Rsyslog_start_master
			else
				ocf_log error "Could not demote Rsyslog because the stop action failed."
				return $OCF_ERR_GENERIC
			fi
			break
			;;
		#$OCF_NOT_RUNNING)
		#	ocf_log error "Trying to promote Rsyslog but it was not started."
		#	return $OCF_ERR_GENERIC
		#	;;
		$OCF_RUNNING_MASTER)
			ocf_log info "Rsyslog successfully promoted."
			return $OCF_SUCCESS
		esac
		$first_try || sleep 1
		first_try=false
	done

	return $rc
}

Rsyslog_stop() {
	# Test if service is stopped already
	Rsyslog_monitor
	if [ $? = $OCF_NOT_RUNNING ]; then
		ocf_log info "Rsyslog service ist not running."
		return $OCF_SUCCESS
	fi

	# Stop service
	/bin/kill `cat ${OCF_RESKEY_pidfile}` > /dev/null
	rc=$?
	if [ $rc != 0 ]; then
		ocf_log err "Rsyslog could not be stopped. Return value of /bin/kill: $rc."
		return $OCF_ERR_GENERIC
	fi
	rm -f ${OCF_RESKEY_pidfile}
	ocf_log info "Rsyslog service stopped."
	return $OCF_SUCCESS
}

Rsyslog_monitor() {
    # Check if Rsyslog is running
	# Check if process id file exists
	if [ ! -r ${OCF_RESKEY_pidfile} ]; then
		return $OCF_NOT_RUNNING
	fi
	# Check if process id in pidfile matches with output of ps
	if read pid < ${OCF_RESKEY_pidfile} && ps -p $pid > /dev/null 2>&1; then
		# Determine state with the output of ps
		PS_OUTPUT=`ps aux | grep rsyslogd`
		# Check if Rsyslog is running with master config
		if [ `expr match "$PS_OUTPUT" ".*$OCF_RESKEY_master_config.*"` != "0" ]; then
			# Check if Rsyslog is listening on port
			#NMAP_OUTPUT=`${OCF_RESKEY_nmap_binfile} -sU -p ${OCF_RESKEY_port} 127.0.0.1 | grep $OCF_RESKEY_port`
			#if [ `expr match "$NMAP_OUTPUT" ".*open.*"` != "0" ]; then
				return $OCF_RUNNING_MASTER
			#else
			#	ocf_log err "Rsyslog seems to be running, but doesn't listen on UDP port ${OCF_RESKEY_port}."
			#	return $OCF_ERR_GENERIC
			#fi
		else
			# Rsyslog is running as slave
			return $OCF_SUCCESS
		fi
	else
		ocf_log err "Rsyslog service is not running but the process id file exists."
		return $OCF_ERR_GENERIC
	fi
	return $OCF_NOT_RUNNING
}

Rsyslog_validate() {
	# Test if Rsyslog executable file exists and is executable
	if [ ! -x ${OCF_RESKEY_binfile} ]; then
		ocf_log err "Rsyslog binary $OCF_RESKEY_binfile does not exist or is not executable."
		return $OCF_ERR_INSTALLED
	fi
	
	# Test if configs exist
	if [ ! -f ${OCF_RESKEY_master_config} ]; then
		ocf_log err "Rsyslog master config file $OCF_RESKEY_master_config does not exist."
		return $OCF_ERR_CONFIGURED
	fi
	if [ ! -f ${OCF_RESKEY_slave_config} ]; then
		ocf_log err "Rsyslog slave config file $OCF_RESKEY_slave_config does not exist."
		return $OCF_ERR_CONFIGURED
	fi
	
	# Test if directory for pid file exists
	PID_DIR=`dirname ${OCF_RESKEY_pidfile}`
	if [ ! -d ${PID_DIR} ]; then
		ocf_log err "The directory to store the pid file does not exist."
		return $OCF_ERR_CONFIGURED
	fi
	
	# Test if portnumber is valid
	if ! ocf_is_decimal "$OCF_RESKEY_port" || [ $OCF_RESKEY_port -le 0 ]; then
		ocf_log err "Portnumber is invalid."
		return $OCF_ERR_CONFIGURED
	fi
	
	# Test if nmap executable file exists and is executable
	if [ ! -x ${OCF_RESKEY_nmap_binfile} ]; then
		ocf_log err "nmap binary $OCF_RESKEY_nmap_binfile does not exist or is not executable."
		return $OCF_ERR_INSTALLED
	fi
	
	return $OCF_SUCCESS
}

#----------------------------------------------------------------------
# Main script
#----------------------------------------------------------------------
case $__OCF_ACTION in
meta-data)
	meta_data
	exit $OCF_SUCCESS
	;;
usage|help)
	Rsyslog_usage 
	exit $OCF_SUCCESS
esac

#Rsyslog_validate
case $__OCF_ACTION in
start)
	Rsyslog_start
	;;
promote)
	Rsyslog_promote
	;;
demote)
	Rsyslog_demote
	;;
stop)
	Rsyslog_stop
	;;
monitor)
	Rsyslog_monitor
	;;
validate-all)
	Rsyslog_validate
	;;
*)
	Rsyslog_usage 
	exit $OCF_ERR_UNIMPLEMENTED;;
esac
rc=$?
ocf_log debug "${OCF_RESOURCE_INSTANCE} $__OCF_ACTION : $rc"
exit $rc