#!/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 the Internet web server. 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 # - forward the radiation data to other services # - write the processed weather 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 # import urllib2 import time import calendar import subprocess import sys import os import json import multiprocessing ### FILE AND FOLDER LOCATIONS ### _TMP_DIRECTORY = "/tmp/radmon" # folder for charts and output data file _RRD_FILE = "/home/{user}/database/radmonData.rrd" # database that stores the data _OUTPUT_DATA_FILE = "/tmp/radmon/radmonData.js" # output file used by HTML docs ### GLOBAL CONSTANTS ### _DEFAULT_WEB_DATA_UPDATE_INTERVAL = 10 _CHART_UPDATE_INTERVAL = 60 # defines how often the charts get updated _DATABASE_UPDATE_INTERVAL = 30 # defines how often the database gets updated _HTTP_REQUEST_TIMEOUT = 5 # number seconds to wait for a response to HTTP request ### GLOBAL VARIABLES ### webUpdateInterval = _DEFAULT_WEB_DATA_UPDATE_INTERVAL # web update frequency deviceUrl = "{your URL}" # radiation monitor network address deviceOnline = True debugOption = False ### PRIVATE METHODS ### def getTimeStamp(): """ Sets the error message time stamp to the local system time. Parameters: none Returns string containing the time stamp. """ return time.strftime( "%Y/%m/%d %T", time.localtime() ) ##end def def setOfflineStatus(dData): """Set the status of the the upstream device to "offline" and sends blank data to the downstream clients. Parameters: dData - dictionary object containing weather data Returns nothing. """ global deviceOnline # If the radiation monitor was previously online, then send a message # that we are now offline. if deviceOnline: print "%s: radmon offline" % getTimeStamp() deviceOnline = False # Set data items to blank. dData['UTC'] = '' dData['CPM'] = '' dData['CPS'] = '' dData['uSvPerHr'] = '' dData['Mode'] = '' dData['status'] = 'offline' writeOutputDataFile(dData) return ##end def ### PUBLIC METHODS ### def getRadmonData(deviceUrl, HttpRequestTimeout): """Send http request to radiation monitoring device. The response from the device contains the radiation data. The data is formatted as an html document. Parameters: deviceUrl - url of radiation monitoring device HttpRequesttimeout - how long to wait for device to respond to http request Returns a string containing the radiation data, or None if not successful. """ global deviceOnline try: conn = urllib2.urlopen(deviceUrl + "/rdata", timeout=HttpRequestTimeout) 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 set the status of the device to offline. if debugOption: print "getRadmonData: %s\n" % exError return None # If the radiation monitor was previously offline, then send a message # that we are now online. if not deviceOnline: print "%s radmon online" % getTimeStamp() deviceOnline = True # Format received data into a single string. content = "" for line in conn: content += line.strip() del conn 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' return True ##end def def convertData(dData): """Convert individual radiation data items as necessary. Parameters: lsData - a list object containing the radiation data dData - a dictionary object containing the radiation data Returns true if successful, false otherwise. """ result = True try: # Convert UTC from radiation monitoring device to local time. ts_utc = time.strptime(dData['UTC'], "%H:%M:%S %m/%d/%Y") local_sec = calendar.timegm(ts_utc) dData['UTC'] = local_sec dData['uSvPerHr'] = dData.pop('uSv/hr') dData['Mode'] = dData.pop('Mode').lower() except Exception, exError: print "%s convertData: %s" % (getTimeStamp(), exError) result = False return result ##end def def writeOutputDataFile(dData): """Convert individual weather string data items as necessary. Parameters: lsData - a list object containing the data to be written to the JSON file Returns true if successful, false otherwise. """ # Set date to current time and data dData['date'] = getTimeStamp() # Format the weather data as string using java script object notation. sData = '[{' for key in dData: sData += "\"%s\":\"%s\"," % (key, dData[key]) sData = sData[:-1] + '}]\n' # 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 if debugOption: print sData return True ## end def def updateDatabase(dData): """ Updates the rrdtool database by executing an rrdtool system command. Formats 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. """ # The RR database stores whole units, so convert uSv to Sv. Svvalue = float(dData['uSvPerHr']) * 1.0E-06 # convert micro-Sieverts to Sieverts # Create the rrdtool update command. strCmd = "rrdtool update %s %s:%s:%s" % \ (_RRD_FILE, dData['UTC'], dData['CPM'], Svvalue) if debugOption: print "%s\n" % 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) return False return True ##end def def createGraph(fileName, dataItem, gTitle, gStart): """Uses rrdtool to create a graph of specified weather data item. Parameters: fileName - name of graph image file dataItem - data item to be graphed gTitle - a title for the graph gStart - beginning time of the data to be graphed Returns true if successful, false otherwise. """ gPath = _TMP_DIRECTORY + '/' + fileName + ".png" # Create the rrdtool graph command. strFmt = ("rrdtool graph %s -a PNG -s %s -w 600 -h 150 " ## "-l 50 -u 110 -r " "-v %s -t %s " "DEF:%s=%s:%s:AVERAGE " "LINE2:%s\#0400ff:") strCmd = strFmt % (gPath, gStart, dataItem, gTitle, dataItem, \ _RRD_FILE, dataItem, dataItem) if debugOption: print "%s\n" % strCmd # DEBUG # Run the command as a subprocess. try: result = subprocess.check_output(strCmd, stderr=subprocess.STDOUT, \ shell=True) except subprocess.CalledProcessError, exError: print "rdtool graph failed: %s" % (exError.output) return False if debugOption: print "rrdtool graph: %s" % result return True ##end def def getCLarguments(): """Get command line arguments. There are three possible arguments -d turns on debug mode -t sets the radiation device query interval -u sets the url of the radiation monitoring device Returns nothing. """ global debugOption, webUpdateInterval, deviceUrl index = 1 while index < len(sys.argv): if sys.argv[index] == '-d': debugOption = True elif sys.argv[index] == '-t': try: webUpdateInterval = abs(int(sys.argv[index + 1])) except: print "invalid polling period" exit(-1) index += 1 elif sys.argv[index] == '-u': deviceUrl = sys.argv[index + 1] index += 1 else: cmd_name = sys.argv[0].split('/') print "Usage: %s {-v} {-d}" % cmd_name[-1] exit(-1) index += 1 ##end def def generateGraphs(): """Generate graphs for display in html documents. Parameters: none Returns nothing. """ createGraph('radGraph1', 'CPM', "'CPM - Last 24 Hours'", 'end-1day') createGraph('radGraph2', 'SvperHr', "'Sv/Hr - Last 24 Hours'", 'end-1day') createGraph('radGraph3', 'CPM', "'CPM - Last 4 Weeks'", 'end-4weeks') createGraph('radGraph4', 'SvperHr', "'Sv/Hr - Last 4 Weeks'", 'end-4weeks') createGraph('radGraph5', 'CPM', "'CPM - Past Year'", 'end-12months') createGraph('radGraph6', 'SvperHr', "'Sv/Hr - Past Year'", 'end-12months') ##end def def main(): """Handles timing of events and acts as executive routine managing all other functions. Parameters: none Returns nothing. """ lastChartUpdateTime = - 1 # last time charts generated lastDatabaseUpdateTime = -1 # last time the rrdtool database updated lastWebUpdateTime = -1 # last time output JSON file updated dData = {} # dictionary object for temporary data storage lsData = [] # list object for temporary data storage ## Get command line arguments. getCLarguments() ## Create www data folder if it does not already exist. if not os.path.isdir(_TMP_DIRECTORY): os.makedirs(_TMP_DIRECTORY) ## Exit with error if cannot find the rrdtool database file. if not os.path.exists(_RRD_FILE): print "cannot find rrdtool database file: terminating" exit(1) ## main loop while True: currentTime = time.time() # At the radiation device query interval request and process # the data from the device. if currentTime - lastWebUpdateTime > webUpdateInterval: lastWebUpdateTime = currentTime result = True # Get the data string from the device. sData = getRadmonData(deviceUrl, _HTTP_REQUEST_TIMEOUT) if sData == None: setOfflineStatus(dData) 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 output file. if result: writeOutputDataFile(dData) # At the rrdtool database update interval, update the database. if currentTime - lastDatabaseUpdateTime > _DATABASE_UPDATE_INTERVAL: lastDatabaseUpdateTime = currentTime if result: ## Update the round robin database with the parsed data. result = updateDatabase(dData) # 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: print "web update: %6f sec\n" % elapsedTime remainingTime = webUpdateInterval - elapsedTime if remainingTime > 0: time.sleep(remainingTime) ## end while ## end def if __name__ == '__main__': main()