//go:generate stringer -type MystromReqStatus main.go
package main
import (
"flag"
"fmt"
"net/http"
"os"
"strings"
"time"
"github.com/gorilla/mux"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
"github.com/prometheus/common/log"
"mystrom-exporter/pkg/mystrom"
"mystrom-exporter/pkg/version"
)
// -- MystromRequestStatusType represents the request to MyStrom device status
type MystromReqStatus uint32
const (
OK MystromReqStatus = iota
ERROR_SOCKET
ERROR_TIMEOUT
ERROR_PARSING_VALUE
)
const namespace = "mystrom_exporter"
var (
listenAddress = flag.String("web.listen-address", ":9452",
"Address to listen on")
metricsPath = flag.String("web.metrics-path", "/metrics",
"Path under which to expose exporters own metrics")
devicePath = flag.String("web.device-path", "/device",
"Path under which the metrics of the devices are fetched")
showVersion = flag.Bool("version", false,
"Show version information.")
)
var (
mystromDurationCounterVec *prometheus.CounterVec
mystromRequestsCounterVec *prometheus.CounterVec
)
var landingPage = []byte(`
myStrom switch report Exporter
myStrom Exporter
Metrics
`)
func main() {
flag.Parse()
// -- show version information
if *showVersion {
v, err := version.Print("mystrom_exporter")
if err != nil {
log.Fatalf("Failed to print version information: %#v", err)
}
fmt.Fprintln(os.Stdout, v)
os.Exit(0)
}
// -- create a new registry for the exporter telemetry
telemetryRegistry := setupMetrics()
router := mux.NewRouter()
router.Handle(*metricsPath, promhttp.HandlerFor(telemetryRegistry, promhttp.HandlerOpts{}))
router.HandleFunc(*devicePath, scrapeHandler)
router.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
w.Write(landingPage)
})
log.Infoln("Listening on address " + *listenAddress)
log.Fatal(http.ListenAndServe(*listenAddress, router))
}
func scrapeHandler(w http.ResponseWriter, r *http.Request) {
target := r.URL.Query().Get("target")
if target == "" {
http.Error(w, "'target' parameter must be specified", http.StatusBadRequest)
return
}
log.Infof("got scrape request for target '%v'", target)
exporter := mystrom.NewExporter(target)
start := time.Now()
gatherer, err := exporter.Scrape()
duration := time.Since(start).Seconds()
if err != nil {
if strings.Contains(fmt.Sprintf("%v", err), "unable to connect with target") {
mystromRequestsCounterVec.WithLabelValues(target, ERROR_SOCKET.String()).Inc()
} else if strings.Contains(fmt.Sprintf("%v", err), "i/o timeout") {
mystromRequestsCounterVec.WithLabelValues(target, ERROR_TIMEOUT.String()).Inc()
} else {
mystromRequestsCounterVec.WithLabelValues(target, ERROR_PARSING_VALUE.String()).Inc()
}
http.Error(
w,
fmt.Sprintf("failed to scrape target '%v': %v", target, err),
http.StatusInternalServerError,
)
log.Error(err)
return
}
mystromDurationCounterVec.WithLabelValues(target).Add(duration)
mystromRequestsCounterVec.WithLabelValues(target, OK.String()).Inc()
promhttp.HandlerFor(gatherer, promhttp.HandlerOpts{}).ServeHTTP(w, r)
}
// -- setupMetrics creates a new registry for the exporter telemetry
func setupMetrics() *prometheus.Registry {
registry := prometheus.NewRegistry()
registry.MustRegister(prometheus.NewGoCollector())
registry.MustRegister(prometheus.NewProcessCollector(prometheus.ProcessCollectorOpts{}))
mystromDurationCounterVec = prometheus.NewCounterVec(
prometheus.CounterOpts{
Namespace: namespace,
Name: "request_duration_seconds_total",
Help: "Total duration of mystrom successful requests by target in seconds",
},
[]string{"target"})
registry.MustRegister(mystromDurationCounterVec)
mystromRequestsCounterVec = prometheus.NewCounterVec(
prometheus.CounterOpts{
Namespace: namespace,
Name: "requests_total",
Help: "Number of mystrom request by status and target",
},
[]string{"target", "status"})
registry.MustRegister(mystromRequestsCounterVec)
// -- make the build information is available through a metric
buildInfo := prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: namespace,
Name: "build_info",
Help: "A metric with a constant '1' value labeled by build information.",
},
[]string{"version", "revision", "branch", "goversion", "builddate", "builduser"},
)
buildInfo.WithLabelValues(version.Version, version.Revision, version.Branch, version.GoVersion, version.BuildDate, version.BuildUser).Set(1)
registry.MustRegister(buildInfo)
return registry
}