Add generic battery metrics

At some point, AVM exposed generic battery metrics (not just in the hkr
elements for thermostats). This change adds two new metrics for devices
running on battery power:
* fritzbox_battery_charge_level
* fritzbox_batterylow

The thermostat specific battery metrics
`fritzbox_thermostat_battery_charge_level` and
`fritzbox_thermostat_batterylow` will be kept around, but should be
considered deprecated.

collector.go

@@ -18,6 +18,8 @@ var (
 type fritzCollector struct {
 	Info                         *prometheus.Desc
 	Present                      *prometheus.Desc
+	BatteryChargeLevel           *prometheus.Desc
+	BatteryLow                   *prometheus.Desc
 	Temperature                  *prometheus.Desc
 	TemperatureOffset            *prometheus.Desc
 	Humidity                     *prometheus.Desc
@@ -39,6 +41,8 @@ type fritzCollector struct {
 func (fc *fritzCollector) Describe(ch chan<- *prometheus.Desc) {
 	ch <- fc.Info
 	ch <- fc.Present
+	ch <- fc.BatteryChargeLevel
+	ch <- fc.BatteryLow
 	ch <- fc.Temperature
 	ch <- fc.TemperatureOffset
 	ch <- fc.Humidity
@@ -81,6 +85,8 @@ func (fc *fritzCollector) Collect(ch chan<- prometheus.Metric) {
 		log.Println("Unable to collect data:", err)
 		ch <- prometheus.NewInvalidMetric(fc.Info, err)
 		ch <- prometheus.NewInvalidMetric(fc.Present, err)
+		ch <- prometheus.NewInvalidMetric(fc.BatteryChargeLevel, err)
+		ch <- prometheus.NewInvalidMetric(fc.BatteryLow, err)
 		ch <- prometheus.NewInvalidMetric(fc.Temperature, err)
 		ch <- prometheus.NewInvalidMetric(fc.TemperatureOffset, err)
 		ch <- prometheus.NewInvalidMetric(fc.Humidity, err)
@@ -127,7 +133,6 @@ func (fc *fritzCollector) Collect(ch chan<- prometheus.Metric) {
 			if err := mustStringToFloatMetric(ch, fc.Temperature, dev.Temperature.FmtCelsius(), &dev); err != nil {
 				log.Printf("Unable to parse temperature data of \"%s\" : %v\n", dev.Name, err)
 			}
-
 			if err := mustStringToFloatMetric(ch, fc.TemperatureOffset, dev.Temperature.FmtOffset(), &dev); err != nil {
 				log.Printf("Unable to parse temperature offset data of \"%s\" : %v\n", dev.Name, err)
 			}
@@ -137,23 +142,31 @@ func (fc *fritzCollector) Collect(ch chan<- prometheus.Metric) {
 			if err := mustStringToFloatMetric(ch, fc.EnergyWh, dev.Powermeter.FmtEnergyWh(), &dev); err != nil {
 				log.Printf("Unable to parse energy data of \"%s\" : %v\n", dev.Name, err)
 			}
-
 			if err := mustStringToFloatMetric(ch, fc.PowerW, dev.Powermeter.FmtPowerW(), &dev); err != nil {
 				log.Printf("Unable to parse power data of \"%s\" : %v\n", dev.Name, err)
 			}
 		}
+
 		if dev.Present == 1 && dev.CanMeasureHumidity() {
 			if err := mustStringToFloatMetric(ch, fc.Humidity, dev.Humidity.FmtRelativeHumidity(), &dev); err != nil {
 				log.Printf("Unable to parse humidity data of \"%s\" : %v\n", dev.Name, err)
 			}
 		}
 
+		if dev.Present == 1 && dev.IsBatteryPowered() {
+			if err := mustStringToFloatMetric(ch, fc.BatteryChargeLevel, dev.BatteryChargeLevel, &dev); err != nil {
+				log.Printf("Unable to parse battery charge level of \"%s\" : %v\n", dev.Name, err)
+			}
+			if err := mustStringToFloatMetric(ch, fc.BatteryLow, dev.BatteryLow, &dev); err != nil {
+				log.Printf("Unable to parse battery low state of \"%s\" : %v\n", dev.Name, err)
+			}
+		}
+
 		if dev.IsThermostat() {
 			// Battery charge level is optional
 			if err := canStringToFloatMetric(ch, fc.ThermostatBatteryChargeLevel, dev.Thermostat.BatteryChargeLevel, &dev); err != nil {
 				log.Printf("Unable to parse battery charge level of \"%s\" : %v\n", dev.Name, err)
 			}
-
 			if err := mustStringToFloatMetric(ch, fc.ThermostatBatteryLow, dev.Thermostat.BatteryLow, &dev); err != nil {
 				log.Printf("Unable to parse battery low state of \"%s\" : %v\n", dev.Name, err)
 			}
@@ -217,6 +230,18 @@ func NewFritzCollector() *fritzCollector {
 			genericLabels,
 			prometheus.Labels{},
 		),
+		BatteryChargeLevel: prometheus.NewDesc(
+			"fritzbox_battery_charge_level",
+			"Battery charge level in percent",
+			genericLabels,
+			prometheus.Labels{},
+		),
+		BatteryLow: prometheus.NewDesc(
+			"fritzbox_batterylow",
+			"0 if the battery is OK, 1 if it is running low on capacity (this seems to be very unreliable)",
+			genericLabels,
+			prometheus.Labels{},
+		),
 		Temperature: prometheus.NewDesc(
 			"fritzbox_temperature",
 			"Temperature measured at the device sensor in units of 0.1 °C",

test/devicelist_729.metrics

@@ -1,3 +1,17 @@
+# HELP fritzbox_battery_charge_level Battery charge level in percent
+# TYPE fritzbox_battery_charge_level gauge
+fritzbox_battery_charge_level{device_id="12345 0000002",device_name="HKR_1",device_type="Comet DECT"} 70
+fritzbox_battery_charge_level{device_id="12345 0000003",device_name="HKR_2",device_type="Comet DECT"} 100
+fritzbox_battery_charge_level{device_id="12345 0000004",device_name="HKR_3",device_type="Comet DECT"} 20
+fritzbox_battery_charge_level{device_id="12345 0000005",device_name="HKR_4",device_type="Comet DECT"} 1
+fritzbox_battery_charge_level{device_id="12345 0000007",device_name="BUTTON_1",device_type="FRITZ!DECT 440"} 100
+# HELP fritzbox_batterylow 0 if the battery is OK, 1 if it is running low on capacity (this seems to be very unreliable)
+# TYPE fritzbox_batterylow gauge
+fritzbox_batterylow{device_id="12345 0000002",device_name="HKR_1",device_type="Comet DECT"} 0
+fritzbox_batterylow{device_id="12345 0000003",device_name="HKR_2",device_type="Comet DECT"} 0
+fritzbox_batterylow{device_id="12345 0000004",device_name="HKR_3",device_type="Comet DECT"} 0
+fritzbox_batterylow{device_id="12345 0000005",device_name="HKR_4",device_type="Comet DECT"} 0
+fritzbox_batterylow{device_id="12345 0000007",device_name="BUTTON_1",device_type="FRITZ!DECT 440"} 0
 # HELP fritzbox_device_info Device information
 # TYPE fritzbox_device_info gauge
 fritzbox_device_info{device_id="12345 0000001",device_name="SW_1",device_type="FRITZ!DECT 200",functionbitmask="35712",fw_version="04.16",internal_id="16",manufacturer="AVM"} 1