package main
import (
"encoding/json"
"flag"
"fmt"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
"io/ioutil"
"log"
"net/http"
"time"
)
type switchReport struct {
Power float64 `json:"power"`
WattPerSec float64 `json:"Ws"`
Relay bool `json:relay`
Temperature float64 `json:"temperature`
}
const namespace = "mystrom"
var (
listenAddress = flag.String("web.listen-address", ":9452",
"Address to listen on")
metricsPath = flag.String("web.metrics-path", "/metrics",
"Path under which to expose metrics")
switchIP = flag.String("switch.ip-address", "",
"IP address of the switch you try to monitor")
up = prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "up"),
"Was the last myStrom query successful.",
nil, nil,
)
myStromPower = prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "report_power"),
"The current power consumed by devices attached to the switch",
nil, nil,
)
myStromRelay = prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "report_relay"),
"The current state of the relay (wether or not the relay is currently turned on)",
nil, nil,
)
myStromTemperature = prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "report_temperatur"),
"The currently measured temperature by the switch. (Might initially be wrong, but will automatically correct itself over the span of a few hours)",
nil, nil,
)
myStromWattPerSec = prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "report_watt_per_sec"),
"The average of energy consumed per second from last call this request",
nil, nil,
)
)
type Exporter struct {
myStromSwitchIp string
}
func NewExporter(myStromSwitchIp string) *Exporter {
return &Exporter{
myStromSwitchIp: myStromSwitchIp,
}
}
func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
ch <- up
ch <- myStromPower
ch <- myStromRelay
ch <- myStromTemperature
ch <- myStromWattPerSec
}
func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
ch <- prometheus.MustNewConstMetric(
up, prometheus.GaugeValue, 1,
)
e.FetchSwitchMetrics(e.myStromSwitchIp, ch)
}
func (e *Exporter) FetchSwitchMetrics(switchIP string, ch chan<- prometheus.Metric) {
url := "http://" + switchIP + "/report"
switchClient := http.Client{
Timeout: time.Second * 5, // 3 second timeout, might need to be increased
}
req, err := http.NewRequest(http.MethodGet, url, nil)
if err != nil {
ch <- prometheus.MustNewConstMetric(
up, prometheus.GaugeValue, 0,
)
}
req.Header.Set("User-Agent", "myStrom-exporter")
res, getErr := switchClient.Do(req)
if getErr != nil {
ch <- prometheus.MustNewConstMetric(
up, prometheus.GaugeValue, 0,
)
}
if res.Body != nil {
defer res.Body.Close()
}
body, readErr := ioutil.ReadAll(res.Body)
if readErr != nil {
ch <- prometheus.MustNewConstMetric(
up, prometheus.GaugeValue, 0,
)
}
report := switchReport{}
err = json.Unmarshal(body, &report)
if err != nil {
fmt.Println(err)
ch <- prometheus.MustNewConstMetric(
up, prometheus.GaugeValue, 0,
)
return
}
ch <- prometheus.MustNewConstMetric(
myStromPower, prometheus.GaugeValue, report.Power,
)
if report.Relay {
ch <- prometheus.MustNewConstMetric(
myStromRelay, prometheus.GaugeValue, 1,
)
} else {
ch <- prometheus.MustNewConstMetric(
myStromRelay, prometheus.GaugeValue, 0,
)
}
ch <- prometheus.MustNewConstMetric(
myStromWattPerSec, prometheus.GaugeValue, report.WattPerSec,
)
ch <- prometheus.MustNewConstMetric(
myStromTemperature, prometheus.GaugeValue, report.Temperature,
)
}
func main() {
flag.Parse()
exporter := NewExporter(*switchIP)
prometheus.MustRegister(exporter)
http.Handle(*metricsPath, promhttp.Handler())
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte(`
myStrom switch report Exporter
myStrom Exporter
Metrics
`))
})
log.Fatal(http.ListenAndServe(*listenAddress, nil))
}