initial wrapper around Prusa Connect API

2022-02-06 16:17:52 -05:00
commit 42b290c3bb
4 changed files with 611 additions and 0 deletions
--- a/main.go
+++ b/main.go
@@ -0,0 +1,130 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"flag"
+	"io"
+	"log"
+	"net/http"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+type Metrics struct {
+	TempNozzle    int     `json:"temp_nozzle"`
+	TempBed       int     `json:"temp_bed"`
+	Material      string  `json:"material"`
+	ZPosition     float64 `json:"pos_z_mm"`
+	PrintingSpeed int     `json:"printing_speed"`
+	FlowFactor    int     `json:"flow_factor"`
+}
+
+type Config struct {
+	QueryHostname string
+	QueryInterval int
+	Port          string
+	Path          string
+}
+
+var (
+	opsFlowFactor = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "prusa_connect",
+		Name:      "flow_factor",
+		Help:      "Current flow factor, as a percentage",
+	})
+	opsPrintSpeed = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "prusa_connect",
+		Name:      "printing_speed",
+		Help:      "Current print speed, as a percentage",
+	})
+	opsZPosition = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "prusa_connect",
+		Name:      "z_position",
+		Help:      "Depth, in MM, of the Z head",
+	})
+	opsBed = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "prusa_connect",
+		Name:      "temp_bed",
+		Help:      "Temperature, in celsius, of the print bed",
+	})
+	opsNozzle = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "prusa_connect",
+		Name:      "temp_nozzle",
+		Help:      "Temperature, in celsius, of the print nozzle",
+	})
+)
+
+func recordMetrics(ctx context.Context, config Config) {
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				log.Print("exiting!")
+				return
+			default:
+				time.Sleep(time.Second * time.Duration(config.QueryInterval))
+				res, err := http.Get(config.QueryHostname + "/api/telemetry")
+				if err != nil {
+					log.Printf("error retrieving telemetry: %v", err)
+					break
+				}
+				b, err := io.ReadAll(res.Body)
+				if err != nil {
+					log.Printf("error retrieving telemetry: %v", err)
+					break
+				}
+				t := &Metrics{}
+				err = json.Unmarshal(b, t)
+				if err != nil {
+					log.Printf("error parsing telemetry: %v", err)
+					break
+				}
+				opsFlowFactor.Set(float64(t.FlowFactor))
+				opsPrintSpeed.Set(float64(t.PrintingSpeed))
+				opsZPosition.Set(t.ZPosition)
+				opsBed.Set(float64(t.TempBed))
+				opsNozzle.Set(float64(t.TempNozzle))
+			}
+		}
+	}()
+}
+
+func main() {
+	var hostname string
+	flag.StringVar(&hostname, "hostname", "localhost", "Hostname the Prusa Connect API is available at (assumes http)")
+	var queryInterval int
+	flag.IntVar(&queryInterval, "interval", 2, "How often, in seconds, to query the API")
+	var port string
+	flag.StringVar(&port, "port", "2112", "Local port to export metrics on")
+	var path string
+	flag.StringVar(&path, "path", "metrics", "Local path to export metrics on")
+	flag.Parse()
+
+	if queryInterval < 1 {
+		log.Fatalf("query interval must be greater than 0; %d received", queryInterval)
+	}
+
+	config := Config{
+		QueryHostname: "http://" + hostname,
+		QueryInterval: queryInterval,
+		Port:          port,
+		Path:          path,
+	}
+
+	r := prometheus.NewRegistry()
+	r.MustRegister(opsNozzle)
+	r.MustRegister(opsBed)
+	r.MustRegister(opsZPosition)
+	r.MustRegister(opsPrintSpeed)
+	r.MustRegister(opsFlowFactor)
+
+	recordMetrics(context.Background(), config)
+
+	log.Printf("starting exporter on :%v", config.Port)
+
+	http.Handle("/"+config.Path, promhttp.HandlerFor(r, promhttp.HandlerOpts{}))
+	http.ListenAndServe(":"+config.Port, nil)
+}