#!/usr/bin/python -u # The -u option above turns off block buffering of python output. This # assures that each error message gets individually printed to the log file. # # Module: radmonAgent.py # # Description: This module acts as an agent between the radiation monitoring # device and Internet web services. The agent periodically sends an http # request to the radiation monitoring device and processes the response from # the device and performs a number of operations: # - conversion of data items # - update a round robin (rrdtool) database with the radiation data # - periodically generate graphic charts for display in html documents # - write the processed radmon data to a JSON file for use by html # documents # # Copyright 2015 Jeff Owrey # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program. If not, see http://www.gnu.org/license. # # Revision History # * v20 released 15 Sep 2015 by J L Owrey; first release # * v21 released 27 Nov 2017 by J L Owrey; bug fixes; updates # * v22 released 03 Mar 2018 by J L Owrey; improved code readability; # improved radmon device offline status handling # * v23 released 16 Nov 2018 by J L Owrey: improved fault handling # and data conversion #2345678901234567890123456789012345678901234567890123456789012345678901234567890 import os import urllib2 import sys import signal import subprocess import multiprocessing import time import calendar _USER = os.environ['USER'] ### DEFAULT RADIATION MONITOR URL ### # ip address of radiation monitoring device _DEFAULT_RADIATION_MONITOR_URL = "http://192.168.1.24" ### FILE AND FOLDER LOCATIONS ### # folder for containing dynamic data objects _DOCROOT_PATH = "/home/%s/public_html/radmon/" % _USER # folder for charts and output data file _CHARTS_DIRECTORY = _DOCROOT_PATH + "dynamic/" # location of data output file _OUTPUT_DATA_FILE = _DOCROOT_PATH + "dynamic/radmonOutputData.js" # database that stores radmon data _RRD_FILE = "/home/%s/database/radmonData.rrd" % _USER ### GLOBAL CONSTANTS ### # max number of failed data requests allowed _MAX_FAILED_DATA_REQUESTS = 2 # interval in seconds between data requests to radiation monitor _DEFAULT_DATA_REQUEST_INTERVAL = 5 # defines how often the charts get updated in seconds _CHART_UPDATE_INTERVAL = 300 # defines how often the database gets updated _DATABASE_UPDATE_INTERVAL = 30 # number seconds to wait for a response to HTTP request _HTTP_REQUEST_TIMEOUT = 3 # standard chart width in pixels _CHART_WIDTH = 600 # standard chart height in pixels _CHART_HEIGHT = 150 # source of time stamp attached to output data file _USE_RADMON_TIMESTAMP = True ### GLOBAL VARIABLES ### # turn on or off of verbose debugging information debugOption = False verboseDebug = False # The following two items are used for detecting system faults # and radiation monitor online or offline status. # count of failed attempts to get data from radiation monitor failedUpdateCount = 0 # detected status of radiation monitor device stationOnline = True # status of reset command to radiation monitor remoteDeviceReset = False # ip address of radiation monitor radiationMonitorUrl = _DEFAULT_RADIATION_MONITOR_URL # web update frequency dataRequestInterval = _DEFAULT_DATA_REQUEST_INTERVAL ### PRIVATE METHODS ### def getTimeStamp(): """ Set the error message time stamp to the local system time. Parameters: none Returns: string containing the time stamp """ return time.strftime( "%m/%d/%Y %T", time.localtime() ) ##end def def setStatusToOffline(): """Set the detected status of the radiation monitor to "offline" and inform downstream clients by removing input and output data files. Parameters: none Returns: nothing """ global stationOnline # Inform downstream clients by removing output data file. if os.path.exists(_OUTPUT_DATA_FILE): os.remove(_OUTPUT_DATA_FILE) # If the radiation monitor was previously online, then send # a message that we are now offline. if stationOnline: print '%s radiation monitor offline' % getTimeStamp() stationOnline = False ##end def def terminateAgentProcess(signal, frame): """Send a message to log when the agent process gets killed by the operating system. Inform downstream clients by removing input and output data files. Parameters: signal, frame - dummy parameters Returns: nothing """ # Inform downstream clients by removing output data file. if os.path.exists(_OUTPUT_DATA_FILE): os.remove(_OUTPUT_DATA_FILE) print '%s terminating radmon agent process' % \ (getTimeStamp()) sys.exit(0) ##end def ### PUBLIC METHODS ### def getRadiationData(): """Send http request to radiation monitoring device. The response from the device contains the radiation data as unformatted ascii text. Parameters: none Returns: a string containing the radiation data if successful, or None if not successful """ global remoteDeviceReset sUrl = radiationMonitorUrl if remoteDeviceReset: sUrl += "/reset" # reboot the radiation monitor else: sUrl += "/rdata" # request data from the monitor try: conn = urllib2.urlopen(sUrl, timeout=_HTTP_REQUEST_TIMEOUT) # Format received data into a single string. content = "" for line in conn: content += line.strip() del conn except Exception, exError: # If no response is received from the device, then assume that # the device is down or unavailable over the network. In # that case return None to the calling function. if debugOption: print "http error: %s" % exError return None return content ##end def def parseDataString(sData, dData): """Parse the radiation data JSON string from the radiation monitoring device into its component parts. Parameters: sData - the string containing the data to be parsed dData - a dictionary object to contain the parsed data items Returns: True if successful, False otherwise """ try: sTmp = sData[2:-2] lsTmp = sTmp.split(',') except Exception, exError: print "%s parseDataString: %s" % (getTimeStamp(), exError) return False # Load the parsed data into a dictionary for easy access. for item in lsTmp: if "=" in item: dData[item.split('=')[0]] = item.split('=')[1] dData['status'] = 'online' # Verfy the expected number of data items have been received. if len(dData) != 6: print "%s parse failed: corrupted data string" % getTimeStamp() return False; return True ##end def def convertData(dData): """Convert individual radiation data items as necessary. Parameters: dData - a dictionary object containing the radiation data Returns: True if successful, False otherwise """ try: if _USE_RADMON_TIMESTAMP: # Convert the UTC timestamp provided by the radiation monitoring # device to epoch local time in seconds. ts_utc = time.strptime(dData['UTC'], "%H:%M:%S %m/%d/%Y") epoch_local_sec = calendar.timegm(ts_utc) dData['ELT'] = epoch_local_sec else: # Use a timestamp generated by the requesting server (this) # instead of the timestamp provided by the radiation monitoring # device. Using the server generated timestamp prevents errors # that occur when the radiation monitoring device fails to # synchronize with a valid NTP time server. dData['ELT'] = time.time() dData['Mode'] = dData['Mode'].lower() dData['uSvPerHr'] = '%.2f' % float(dData.pop('uSv/hr')) except Exception, exError: print "%s data conversion failed: %s" % (getTimeStamp(), exError) return False return True ##end def def writeOutputDataFile(dData): """Write radiation data items to the output data file, formatted as a Javascript file. This file may then be accessed and used by by downstream clients, for instance, in HTML documents. Parameters: dData - a dictionary object containing the data to be written to the output data file Returns: True if successful, False otherwise """ # Create temporary copy of output data items. dTemp = dict(dData) # Set date to current time and data dTemp['date'] = time.strftime("%m/%d/%Y %T", time.localtime(dData['ELT'])) # Remove unnecessary data items. dTemp.pop('ELT') dTemp.pop('UTC') # Format the radmon data as string using java script object notation. sData = '[{' for key in dTemp: sData += '\"%s\":\"%s\",' % (key, dTemp[key]) sData = sData[:-1] + '}]\n' if verboseDebug: print sData, # Write the string to the output data file for use by html documents. try: fc = open(_OUTPUT_DATA_FILE, "w") fc.write(sData) fc.close() except Exception, exError: print "%s writeOutputDataFile: %s" % (getTimeStamp(), exError) return False return True ## end def def setStationStatus(updateSuccess): """Detect if radiation monitor is offline or not available on the network. After a set number of attempts to get data from the monitor set a flag that the station is offline. Parameters: updateSuccess - a boolean that is True if data request successful, False otherwise Returns: nothing """ global failedUpdateCount, stationOnline if updateSuccess: failedUpdateCount = 0 # Set status and send a message to the log if the station was # previously offline and is now online. if not stationOnline: print '%s radiation monitor online' % getTimeStamp() stationOnline = True if debugOption: print 'data request successful' else: # The last attempt failed, so update the failed attempts # count. failedUpdateCount += 1 if debugOption: print 'data request failed' if failedUpdateCount >= _MAX_FAILED_DATA_REQUESTS: # Max number of failed data requests, so set # monitor status to offline. setStatusToOffline() ##end def def updateDatabase(dData): """ Update the rrdtool database by executing an rrdtool system command. Format the command using the data extracted from the radiation monitor response. Parameters: dData - dictionary object containing data items to be written to the rr database file Returns: True if successful, False otherwise """ global remoteDeviceReset # The RR database stores whole units, so convert uSv to Sv. SvPerHr = float(dData['uSvPerHr']) * 1.0E-06 # Format the rrdtool update command. strCmd = "rrdtool update %s %s:%s:%s" % \ (_RRD_FILE, dData['ELT'], dData['CPM'], SvPerHr) if verboseDebug: print "%s" % strCmd # DEBUG # Run the command as a subprocess. try: subprocess.check_output(strCmd, shell=True, \ stderr=subprocess.STDOUT) except subprocess.CalledProcessError, exError: print "%s: rrdtool update failed: %s" % \ (getTimeStamp(), exError.output) if exError.output.find("illegal attempt to update using time") > -1: remoteDeviceReset = True print "%s: rebooting radiation monitor" % (getTimeStamp()) return False else: if debugOption: print 'database update sucessful' return True ##end def def createGraph(fileName, dataItem, gLabel, gTitle, gStart, lower, upper, addTrend, autoScale): """Uses rrdtool to create a graph of specified radmon data item. Parameters: fileName - name of file containing the graph dataItem - data item to be graphed gLabel - string containing a graph label for the data item gTitle - string containing a title for the graph gStart - beginning time of the graphed data lower - lower bound for graph ordinate #NOT USED upper - upper bound for graph ordinate #NOT USED addTrend - 0, show only graph data 1, show only a trend line 2, show a trend line and the graph data autoScale - if True, then use vertical axis auto scaling (lower and upper parameters are ignored), otherwise use lower and upper parameters to set vertical axis scale Returns: True if successful, False otherwise """ gPath = _CHARTS_DIRECTORY + fileName + ".png" trendWindow = { 'end-1day': 7200, 'end-4weeks': 172800, 'end-12months': 604800 } # Format the rrdtool graph command. # Set chart start time, height, and width. strCmd = "rrdtool graph %s -a PNG -s %s -e now -w %s -h %s " \ % (gPath, gStart, _CHART_WIDTH, _CHART_HEIGHT) # Set the range and scaling of the chart y-axis. if lower < upper: strCmd += "-l %s -u %s -r " % (lower, upper) elif autoScale: strCmd += "-A " strCmd += "-Y " # Set the chart ordinate label and chart title. strCmd += "-v %s -t %s " % (gLabel, gTitle) # Show the data, or a moving average trend line over # the data, or both. strCmd += "DEF:dSeries=%s:%s:LAST " % (_RRD_FILE, dataItem) if addTrend == 0: strCmd += "LINE1:dSeries#0400ff " elif addTrend == 1: strCmd += "CDEF:smoothed=dSeries,%s,TREND LINE3:smoothed#ff0000 " \ % trendWindow[gStart] elif addTrend == 2: strCmd += "LINE1:dSeries#0400ff " strCmd += "CDEF:smoothed=dSeries,%s,TREND LINE3:smoothed#ff0000 " \ % trendWindow[gStart] if verboseDebug: print "\n%s" % strCmd # DEBUG # Run the formatted rrdtool command as a subprocess. try: result = subprocess.check_output(strCmd, \ stderr=subprocess.STDOUT, \ shell=True) except subprocess.CalledProcessError, exError: print "rrdtool graph failed: %s" % (exError.output) return False if debugOption: print "rrdtool graph: %s" % result, return True ##end def def generateGraphs(): """Generate graphs for display in html documents. Parameters: none Returns: nothing """ autoScale = False createGraph('24hr_cpm', 'CPM', 'counts\ per\ minute', 'CPM\ -\ Last\ 24\ Hours', 'end-1day', 0, 0, 2, autoScale) createGraph('24hr_svperhr', 'SvperHr', 'Sv\ per\ hour', 'Sv/Hr\ -\ Last\ 24\ Hours', 'end-1day', 0, 0, 2, autoScale) createGraph('4wk_cpm', 'CPM', 'counts\ per\ minute', 'CPM\ -\ Last\ 4\ Weeks', 'end-4weeks', 0, 0, 2, autoScale) createGraph('4wk_svperhr', 'SvperHr', 'Sv\ per\ hour', 'Sv/Hr\ -\ Last\ 4\ Weeks', 'end-4weeks', 0, 0, 2, autoScale) createGraph('12m_cpm', 'CPM', 'counts\ per\ minute', 'CPM\ -\ Past\ Year', 'end-12months', 0, 0, 2, autoScale) createGraph('12m_svperhr', 'SvperHr', 'Sv\ per\ hour', 'Sv/Hr\ -\ Past\ Year', 'end-12months', 0, 0, 2, autoScale) ##end def def getCLarguments(): """Get command line arguments. There are four possible arguments -d turns on debug mode -v turns on verbose debug mode -t sets the radiation device query interval -u sets the url of the radiation monitoring device Returns: nothing """ global debugOption, verboseDebug, dataRequestInterval, \ radiationMonitorUrl index = 1 while index < len(sys.argv): if sys.argv[index] == '-d': debugOption = True elif sys.argv[index] == '-v': debugOption = True verboseDebug = True elif sys.argv[index] == '-t': try: dataRequestInterval = abs(int(sys.argv[index + 1])) except: print "invalid polling period" exit(-1) index += 1 elif sys.argv[index] == '-u': radiationMonitorUrl = sys.argv[index + 1] index += 1 else: cmd_name = sys.argv[0].split('/') print "Usage: %s [-d] [-t seconds] [-u url}" % cmd_name[-1] exit(-1) index += 1 ##end def def main(): """Handles timing of events and acts as executive routine managing all other functions. Parameters: none Returns: nothing """ signal.signal(signal.SIGTERM, terminateAgentProcess) print '%s starting up radmon agent process' % \ (getTimeStamp()) # last time output JSON file updated lastDataRequestTime = -1 # last time charts generated lastChartUpdateTime = - 1 # last time the rrdtool database updated lastDatabaseUpdateTime = -1 ## Get command line arguments. getCLarguments() ## Exit with error if rrdtool database does not exist. if not os.path.exists(_RRD_FILE): print 'rrdtool database does not exist\n' \ 'use createRadmonRrd script to ' \ 'create rrdtool database\n' exit(1) ## main loop while True: currentTime = time.time() # get current time in seconds # Every web update interval request data from the radiation # monitor and process the received data. if currentTime - lastDataRequestTime > dataRequestInterval: lastDataRequestTime = currentTime dData = {} result = True # Get the data string from the device. sData = getRadiationData() if sData == None: result = False # If successful parse the data. if result: result = parseDataString(sData, dData) # If parsing successful, convert the data. if result: result = convertData(dData) # If conversion successful, write data to data files. if result: writeOutputDataFile(dData) # At the rrdtool database update interval, update the database. if currentTime - lastDatabaseUpdateTime > \ _DATABASE_UPDATE_INTERVAL: lastDatabaseUpdateTime = currentTime ## Update the round robin database with the parsed data. updateDatabase(dData) # Set the station status to online or offline depending on the # success or failure of the above operations. setStationStatus(result) # At the chart generation interval, generate charts. if currentTime - lastChartUpdateTime > _CHART_UPDATE_INTERVAL: lastChartUpdateTime = currentTime p = multiprocessing.Process(target=generateGraphs, args=()) p.start() # Relinquish processing back to the operating system until # the next update interval. elapsedTime = time.time() - currentTime if debugOption and not verboseDebug: pass #print if verboseDebug: print "processing time: %6f sec\n" % elapsedTime remainingTime = dataRequestInterval - elapsedTime if remainingTime > 0.0: time.sleep(remainingTime) ## end while return ## end def if __name__ == '__main__': try: main() except KeyboardInterrupt: print '\n', terminateAgentProcess('KeyboardInterrupt','Module')