add /targets api endpoint

get list of configured and discovered targets and configuration

Signed-off-by: Markus Blaschke <[email protected]>

Author: mblaschke

README.md

@@ -80,10 +80,11 @@ scrape_configs:
 HTTP Endpoints
 --------------
 
-| Endpoint   | Description                                                                                                              |
-|------------|--------------------------------------------------------------------------------------------------------------------------|
-| `/metrics` | Default prometheus golang metrics                                                                                        |
-| `/probe`   | Probe shelly plugs, uses mDNS servicediscovery to find Shelly plugs (must be run on host network)                        |
+| Endpoint   | Description                                                                                       |
+|------------|---------------------------------------------------------------------------------------------------|
+| `/metrics` | Default prometheus golang metrics                                                                 |
+| `/probe`   | Probe shelly plugs, uses mDNS servicediscovery to find Shelly plugs (must be run on host network) |
+| `/targets` | List of configured and discovered targets as JSON                                                 |
 
 Metrics
 -------

main.go

@@ -88,6 +88,7 @@ func startHttpServer() {
 
 	mux.Handle("/metrics", promhttp.Handler())
 	mux.HandleFunc("/probe", shellyProbeDiscovery)
+	mux.HandleFunc("/targets", shellyProbeDiscoveryTargets)
 
 	srv := &http.Server{
 		Addr:         Opts.Server.Bind,

probe.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"net/http"
 	"strconv"
@@ -29,6 +30,35 @@ func newShellyProber(ctx context.Context, registry *prometheus.Registry, logger
 	return sp
 }
 
+func shellyProbeDiscoveryTargets(w http.ResponseWriter, r *http.Request) {
+	registry := prometheus.NewRegistry()
+
+	contextLogger := buildContextLoggerFromRequest(r)
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(30*float64(time.Second)))
+	defer cancel()
+
+	sp := newShellyProber(ctx, registry, contextLogger)
+	sp.UseDiscovery()
+
+	targets := sp.GetTargets()
+
+	body, err := json.Marshal(targets)
+	if err != nil {
+		contextLogger.Error(err)
+		http.Error(w, fmt.Sprintf("unable to marshal targets to json: %s", err), http.StatusBadRequest)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	_, err = w.Write(body)
+	if err != nil {
+		contextLogger.Error(err)
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+}
+
 func shellyProbeDiscovery(w http.ResponseWriter, r *http.Request) {
 	var err error
 	var timeoutSeconds float64