Server Room Temperature Probe

update_temp.py

#!/usr/bin/python
import sys
import rrdtool
import json

MIN_TEMP = 0
ERROR_TEMP = -999.99

TEMP_SENSORS = {
	"E" : {"sensor":"28-00043a4518ff","location":"Server Room Rack B/C (Back)","temperature":{"celsius":None,"fahrenheit":None}},
	"A" : {"sensor":"28-00043e827cff","location":"Server Room Rack A (Ambient)","temperature":{"celsius":None,"fahrenheit":None}},
	"B" : {"sensor":"28-00043b61b4ff","location":"Server Room Rack E (Ambient)","temperature":{"celsius":None,"fahrenheit":None}},
	"D" : {"sensor":"28-00043a52a1ff","location":"Server Room Rack D/E (Back)","temperature":{"celsius":None,"fahrenheit":None}},
	"C" : {"sensor":"28-00043b6803ff","location":"Server Room Rack C/D (Back)","temperature":{"celsius":None,"fahrenheit":None}},
}

def create_rrd():
	ret = rrdtool.create("temperatures.rrd", "--step", "300", "--start", '0',
						"DS:A:GAUGE:600:U:U",
						"DS:B:GAUGE:600:U:U",
						"DS:C:GAUGE:600:U:U",
						"DS:D:GAUGE:600:U:U",
						"DS:E:GAUGE:600:U:U",
						"RRA:AVERAGE:0.5:1:600",
						"RRA:AVERAGE:0.5:6:700",
						"RRA:AVERAGE:0.5:24:775",
						"RRA:AVERAGE:0.5:288:797",
						"RRA:MAX:0.5:1:600",
						"RRA:MAX:0.5:6:700",
						"RRA:MAX:0.5:24:775",
						"RRA:MAX:0.5:444:797")
	 
	if ret:
	 print rrdtool.error()

def read_temperature(sensor):
	tfile = open("/sys/bus/w1/devices/{0}/w1_slave".format(sensor))
	text = tfile.read()
	tfile.close()
	lines = text.split("\n")
	if lines[0].find("YES") > 0:
		temp = float((lines[1].split(" ")[9])[2:])/1000
		return temp
	return ERROR_TEMP

def create_json():
	# Open a file for writing
	sorted(TEMP_SENSORS)
	out_file = open("/usr/share/nginx/www/temperatures.json","w")
	json.dump(TEMP_SENSORS,out_file, indent=4)
	out_file.close()

def update_rrd():
	for rrd in TEMP_SENSORS:
		celsius = read_temperature(TEMP_SENSORS[rrd]['sensor'])
		TEMP_SENSORS[rrd]['temperature']['celsius'] = celsius
		TEMP_SENSORS[rrd]['temperature']['fahrenheit'] = 9.0/5.0 * celsius + 32

	update_str = "N:{0}:{1}:{2}:{3}:{4}".format(TEMP_SENSORS['A']['temperature']['fahrenheit'],TEMP_SENSORS['B']['temperature']['fahrenheit'],TEMP_SENSORS['C']['temperature']['fahrenheit'],TEMP_SENSORS['D']['temperature']['fahrenheit'],TEMP_SENSORS['E']['temperature']['fahrenheit'])

	ret = rrdtool.update('temperatures.rrd',update_str);
	if ret:
		print rrdtool.error()

def create_graph():
	ret = rrdtool.graph("/usr/share/nginx/www/temperatures.png", "-w 760", "-h 400","--start", "-3d", "--vertical-label=Temperature (F)", '--title', "Server Room Temperature",
						"DEF:A=temperatures.rrd:A:AVERAGE",
						"DEF:B=temperatures.rrd:B:AVERAGE",
						"DEF:C=temperatures.rrd:C:AVERAGE",
						"DEF:D=temperatures.rrd:D:AVERAGE",
						"DEF:E=temperatures.rrd:E:AVERAGE",
						"CDEF:Ambient=A,B,+,2,/",
						"CDEF:ATrend=Ambient,43200,TREND",
						"CDEF:Back=C,D,+,E,+,3,/",
						"CDEF:BTrend=Back,43200,TREND",
						"LINE2:ATrend#FF0000:Ambient Trend",
                                                "LINE2:BTrend#0000FF:Back of Rack Trend"+"\\r",
						"LINE1:A#FF8000:"+TEMP_SENSORS['A']['location'],
						"LINE1:B#A599FF:"+TEMP_SENSORS['B']['location']+"\\r",
						"LINE1:C#557755:"+TEMP_SENSORS['C']['location'],
						"LINE1:D#FF00FF:"+TEMP_SENSORS['D']['location'],
						"LINE1:E#00FF00:"+TEMP_SENSORS['E']['location'])

update_rrd()
create_graph()
create_json()