readme.md

nest_poller

A simple Ruby daemon that reads from the Nest thermostat API (using your personal Nest login credentials), collects some basic stats, and publishes those stats to an instance of InfluxDB somewhere on the Internet. InfluxDB is hooked up to Grafana for visualization in my case.

This is a quick hack for my own personal use and is completely unsupported.

nest_poller_grempe.rb

#!/usr/bin/env ruby

# USAGE
# See : https://github.com/thuehlinger/daemons
#
# ruby nest_poller_control.rb run (foreground)
# ruby nest_poller_control.rb start
# ruby nest_poller_control.rb stop
# ruby nest_poller_control.rb status

require 'rubygems'
require 'bundler/setup'
require 'daemons'
require 'httparty'
require 'influxdb'
require 'awesome_print'

Bundler.setup

# Instructions for getting a long-life access token for API access
# for rempe.us registered API client.
#
# Guide:
# https://developer.nest.com/documentation/cloud/rest-quick-guide
#
# See : https://developer.nest.com/clients for my registered API clients and the URLs.
#
# Step 1 : GET a PIN number
# -  Replace STATE with a random number.
# -  Paste this in a BROWSER as you will have to click a button to authorize.
# -  A PIN code will be returned which you will need for the next step.
#
# GET https://home.nest.com/login/oauth2?client_id=3fb1f2d0-1f87-42f5-a9f8-0b21f142aef5&state=STATE
#
# Step 2 : Copy PIN code.
# e.g. N6B4FV9G
#
# Step 3 : Exchange the authorization PIN code for a long-lived access token
#
# Replace code=AUTHORIZATION_CODE in this URL with the PIN
#
# POST https://api.home.nest.com/oauth2/access_token?client_id=3fb1f2d0-1f87-42f5-a9f8-0b21f142aef5&code=AUTHORIZATION_CODE&client_secret=D1AVcTSab5ERaolisto5uUDIc&grant_type=authorization_code
#
# Step 4 : Extract long-life access token from response which will be used for all future API requests.
#
#    {"access_token":"c.7MVm2...","expires_in":315360000}

NEST_WEATHER_URL = "http://weather.nest.com/weather/v1?query="

Daemons.run_proc('nest_poller.rb', {:backtrace  => true, :monitor => true, :log_output => true}) do

  # influxdb setup
  database = 'nest_poller'
  time_precision = 'm'
  influxdb = InfluxDB::Client.new(database,
                         host: ENV['INFLUXDB_NEST_POLLER_HOST'],
                         username: ENV['INFLUXDB_NEST_POLLER_USERNAME'],
                         password: ENV['INFLUXDB_NEST_POLLER_PASS'])

  loop do

    # influxdb data collection bucket
    data = []

    begin
      api_req = HTTParty.get("https://developer-api.nest.com/?auth=#{ENV['NEST_API_ACCESS_TOKEN']}")
      api_resp = JSON.parse(api_req.body) rescue nil
    rescue Exception => e
      puts "api HTTP req failed : #{e.class} #{e.message}"
      api_resp = nil
    end

    # report the weather for each home structure on the account.
    if api_resp && api_resp["structures"] && api_resp["structures"] && api_resp["structures"].is_a?(Hash)
      # Iterate over all structures to get the outdoor weather for it.
      api_resp["structures"].keys.each do |id|
        postal_code = api_resp["structures"][id]["postal_code"]
        # sample : http://weather.nest.com/weather/v1?query=11746
        outdoor_weather_req = HTTParty.get("#{NEST_WEATHER_URL}#{postal_code}")
        outdoor_weather_resp = JSON.parse(outdoor_weather_req.body) rescue nil

        if outdoor_weather_resp && outdoor_weather_resp[postal_code] && outdoor_weather_resp[postal_code]["current"]
          temp_f = outdoor_weather_resp[postal_code]["current"]["temp_f"]
          condition = outdoor_weather_resp[postal_code]["current"]["condition"]
          humidity = outdoor_weather_resp[postal_code]["current"]["humidity"]

          weather = {}
          weather[:series] = 'weather'
          weather[:values] = {temp_f: temp_f, condition: condition, humidity: humidity }
          weather[:tags]   = {postal_code: postal_code}
          data << weather
        end
      end
    else
      puts "api_resp['structures'] check failed. : #{api_resp}"
    end


    # Iterate over each thermostat and collect the data for it.
    if api_resp && api_resp["devices"] && api_resp["devices"]["thermostats"] && api_resp["devices"]["thermostats"].is_a?(Hash)
      api_resp["devices"]["thermostats"].keys.each do |id|
        d = api_resp["devices"]["thermostats"][id]

        device = {}
        device[:series]                         = 'nest'
        device[:values]                         = {}
        device[:values][:indoor_temp_f]         = d["ambient_temperature_f"]
        device[:values][:indoor_temp_setpoint]  = d["target_temperature_f"]
        device[:values][:indoor_humidity]       = d["humidity"]
        device[:tags]                           = { device_type: 'nest',
                                        structure_id: d["structure_id"],
                                        structure_name: api_resp["structures"][d["structure_id"]]["name"],
                                        device_id: d["device_id"],
                                        device_location: d["name"],
                                        postal_code: api_resp["structures"][d["structure_id"]]["postal_code"]}
        data << device
      end
    else
      puts "api_resp['devices'] check failed. : #{api_resp}"
    end

    # write all collected data for structures and thermostats
    begin
      influxdb.write_points(data, time_precision)
    rescue Exception => e
      puts "influxdb.write_points req failed : #{e.class} : #{e.message}"
      # could not write data points to InfluxDB server. Try again soon.
    end

    sleep(60 * 5) # seconds
  end
end

I'm trying to use a container that uses this code, and it looks like something may be broken with the zip code lookup. it's returning blank data, causing the data to not be written to influx. once i hard-coded a zip instead of using the api call in the 2 locations, i was able to get data into influx without error. the error i was getting is:
influxdb.write_points req failed : InfluxDB::Error : {"error":"unable to parse 'nest,device_type=nest,structure_id=MYID,structure_name=Home,device_id=DEVICEID,device_location=LivingRoom,postal_code= indoor_temp_f=69,indoor_temp_setpoint=68,indoor_humidity=25': missing tag value"}