Add experimental prometheus support.

cmd/invertergui/main.go

@@ -1,5 +1,5 @@
 /*
-Copyright (c) 2015, Hendrik van Wyk
+Copyright (c) 2015, 2017 Hendrik van Wyk
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -34,6 +34,7 @@ import (
 	"flag"
 	"github.com/hpdvanwyk/invertergui/datasource"
 	"github.com/hpdvanwyk/invertergui/webgui"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"log"
 	"net/http"
 	"time"
@@ -50,5 +51,6 @@ func main() {
 	http.Handle("/", gui)
 	http.Handle("/munin", http.HandlerFunc(gui.ServeMuninHTTP))
 	http.Handle("/muninconfig", http.HandlerFunc(gui.ServeMuninConfigHTTP))
+	http.Handle("/metrics", promhttp.Handler())
 	log.Fatal(http.ListenAndServe(":8080", nil))
 }

webgui/prometheus.go

@@ -0,0 +1,134 @@
+/*
+Copyright (c) 2017, Hendrik van Wyk
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+
+* Neither the name of invertergui nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+package webgui
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type prometheusUpdater struct {
+	batteryVoltage  prometheus.Gauge
+	batteryCharge   prometheus.Gauge
+	batteryCurrent  prometheus.Gauge
+	batteryPower    prometheus.Gauge
+	mainsCurrentIn  prometheus.Gauge
+	mainsCurrentOut prometheus.Gauge
+	mainsVoltageIn  prometheus.Gauge
+	mainsVoltageOut prometheus.Gauge
+	mainsPowerIn    prometheus.Gauge
+	mainsPowerOut   prometheus.Gauge
+	mainsFreqIn     prometheus.Gauge
+	mainsFreqOut    prometheus.Gauge
+}
+
+func newPrometheusUpdater() *prometheusUpdater {
+	tmp := &prometheusUpdater{
+		batteryVoltage: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "battery_voltage_v",
+			Help: "Voltage of the battery.",
+		}),
+		batteryCharge: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "battery_charge_percentage",
+			Help: "Remaining battery charge.",
+		}),
+		batteryCurrent: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "battery_current_a",
+			Help: "Battery current.",
+		}),
+		batteryPower: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "battery_power_w",
+			Help: "Battery power.",
+		}),
+		mainsCurrentIn: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "mains_current_in_a",
+			Help: "Mains current flowing into inverter",
+		}),
+		mainsCurrentOut: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "mains_current_out_a",
+			Help: "Mains current flowing out of inverter",
+		}),
+		mainsVoltageIn: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "mains_voltage_in_v",
+			Help: "Mains voltage at input of inverter",
+		}),
+		mainsVoltageOut: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "mains_voltage_out_v",
+			Help: "Mains voltage at output of inverter",
+		}),
+		mainsPowerIn: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "mains_power_in_va",
+			Help: "Mains power in",
+		}),
+		mainsPowerOut: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "mains_power_out_va",
+			Help: "Mains power out",
+		}),
+		mainsFreqIn: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "mains_freq_in_hz",
+			Help: "Mains frequency at inverter input",
+		}),
+		mainsFreqOut: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: "mains_freq_out_hz",
+			Help: "Mains frequency at inverter output",
+		}),
+	}
+	prometheus.MustRegister(tmp.batteryVoltage,
+		tmp.batteryCharge,
+		tmp.batteryCurrent,
+		tmp.batteryPower,
+		tmp.mainsCurrentIn,
+		tmp.mainsCurrentOut,
+		tmp.mainsVoltageIn,
+		tmp.mainsVoltageOut,
+		tmp.mainsPowerIn,
+		tmp.mainsPowerOut,
+		tmp.mainsFreqIn,
+		tmp.mainsFreqOut,
+	)
+	return tmp
+}
+
+func (pu *prometheusUpdater) updatePrometheus(newStatus *statusProcessed) {
+	s := newStatus.status
+	pu.batteryVoltage.Set(s.BatVoltage)
+	pu.batteryCharge.Set(newStatus.chargeLevel)
+	pu.batteryCurrent.Set(s.BatCurrent)
+	pu.batteryCurrent.Set(s.BatVoltage * s.BatCurrent)
+	pu.mainsCurrentIn.Set(s.InCurrent)
+	pu.mainsCurrentOut.Set(s.OutCurrent)
+	pu.mainsVoltageIn.Set(s.InVoltage)
+	pu.mainsVoltageOut.Set(s.OutVoltage)
+	pu.mainsPowerIn.Set(s.InVoltage * s.InCurrent)
+	pu.mainsPowerOut.Set(s.OutVoltage * s.OutCurrent)
+	pu.mainsFreqIn.Set(s.InFreq)
+	pu.mainsFreqIn.Set(s.OutFreq)
+
+}

webgui/webgui.go

@@ -1,5 +1,5 @@
 /*
-Copyright (c) 2015, Hendrik van Wyk
+Copyright (c) 2015, 2017 Hendrik van Wyk
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -68,6 +68,8 @@ type WebGui struct {
 	muninRespChan chan muninData
 	poller        datasource.DataPoller
 	wg            sync.WaitGroup
+
+	pu *prometheusUpdater
 }
 
 func NewWebGui(source datasource.DataPoller, batteryCapacity float64) *WebGui {
@@ -81,6 +83,8 @@ func NewWebGui(source datasource.DataPoller, batteryCapacity float64) *WebGui {
 		panic(err)
 	}
 	w.poller = source
+	w.pu = newPrometheusUpdater()
+
 	w.wg.Add(1)
 	go w.dataPoll(batteryCapacity)
 	return w
@@ -186,6 +190,7 @@ func (w *WebGui) dataPoll(batteryCapacity float64) {
 				}
 				statusP.chargeLevel = tracker.CurrentLevel()
 				calcMuninValues(&muninValues, &statusP)
+				w.pu.updatePrometheus(&statusP)
 			}
 		case w.respChan <- statusP:
 		case w.muninRespChan <- muninValues: