Fix Reach services discovery

- Use github.com/grandcat/zeroconf lib instead of github.com/oleksandr/bonjour

emlid/discovery.go

@@ -1,65 +1,52 @@
 package emlid
 
 import (
+	"context"
 	"net"
 	"sync"
-	"time"
 
-	"github.com/oleksandr/bonjour"
+	"github.com/grandcat/zeroconf"
 )
 
 // Service is a ReachRS service discovered via MDNS-SD
 type Service struct {
 	Name   string
-	AddrV4 net.IP
+	AddrV4 *net.IP
 	Port   int
 }
 
-// Discover tries to discover ReachRS services on the local network via MDNS-SD
+// Discover tries to discover ReachRS services on the local network via mDNS-SD
-func Discover(timeout time.Duration) ([]Service, error) {
+func Discover(ctx context.Context) ([]Service, error) {
 
 	var wg sync.WaitGroup
 
 	wg.Add(1)
 
-	resolver, err := bonjour.NewResolver(nil)
+	resolver, err := zeroconf.NewResolver(nil)
 	if err != nil {
 		return nil, err
 	}
 
 	services := make([]Service, 0)
-	entries := make(chan *bonjour.ServiceEntry)
+	entries := make(chan *zeroconf.ServiceEntry)
-	timer := time.NewTimer(timeout)
-	defer timer.Stop()
-
-	stop := func() {
-		resolver.Exit <- true
-		wg.Done()
-	}
 
 	go func() {
-		for {
+		for e := range entries {
-			select {
+			var addr *net.IP
-
+			if len(e.AddrIPv4) > 0 {
-			case e, ok := <-entries:
+				addr = &e.AddrIPv4[0]
-				if !ok {
-					stop()
-					return
 			}
-				services = append(services, Service{
+			srv := Service{
 				Name:   e.Instance,
-					AddrV4: e.AddrIPv4,
+				AddrV4: addr,
 				Port:   e.Port,
-				})
-
-			case <-timer.C:
-				stop()
-				return
 			}
+			services = append(services, srv)
 		}
+		wg.Done()
 	}()
 
-	if err = resolver.Browse("_reach._tcp", ".local", entries); err != nil {
+	if err = resolver.Browse(ctx, "_reach._tcp", ".local", entries); err != nil {
 		return nil, err
 	}
 

emlid/discovery_test.go

@@ -1,6 +1,7 @@
 package emlid
 
 import (
+	"context"
 	"testing"
 	"time"
 )
@@ -11,7 +12,10 @@ func TestDiscovery(t *testing.T) {
 		t.Skip("To run this test, use: go test -discovery-integration")
 	}
 
-	services, err := Discover(3 * time.Second)
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	services, err := Discover(ctx)
 	if err != nil {
 		t.Fatal(err)
 	}

example/discovery/main.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"log"
+	"time"
+
+	"forge.cadoles.com/Pyxis/orion/emlid"
+)
+
+var (
+	timeout = 5 * time.Second
+)
+
+func init() {
+	flag.DurationVar(&timeout, "timeout", timeout, "mDNS scan timeout")
+}
+
+func main() {
+
+	flag.Parse()
+
+	log.Println("Searching for ReachRS services on network...")
+
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	services, err := emlid.Discover(ctx)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, s := range services {
+		log.Println("Found:")
+		log.Printf("  Name: '%s'", s.Name)
+		log.Printf("  Hosts: %s", s.AddrV4)
+		log.Printf("  Port: '%d'", s.Port)
+	}
+
+}

go.mod

@@ -2,13 +2,14 @@ module forge.cadoles.com/Pyxis/orion
 
 require (
 	forge.cadoles.com/Pyxis/golang-socketio v0.0.0-20180919100209-bb857ced6b95
-	github.com/caarlos0/env v3.3.0+incompatible
+	github.com/caarlos0/env v3.4.0+incompatible
+	github.com/cenkalti/backoff v2.0.0+incompatible // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/go-chi/chi v3.3.3+incompatible
 	github.com/gorilla/websocket v1.4.0 // indirect
+	github.com/grandcat/zeroconf v0.0.0-20180329153754-df75bb3ccae1
 	github.com/miekg/dns v1.0.12 // indirect
-	github.com/mitchellh/mapstructure v1.0.0
+	github.com/mitchellh/mapstructure v1.1.2
-	github.com/oleksandr/bonjour v0.0.0-20160508152359-5dcf00d8b228
 	github.com/pkg/errors v0.8.0
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/stretchr/testify v1.2.2 // indirect

go.sum

@@ -1,19 +1,21 @@
 forge.cadoles.com/Pyxis/golang-socketio v0.0.0-20180919100209-bb857ced6b95 h1:o3G5+9RjczCK1xAYFaRMknk1kY9Ule6PNfiW6N6hEpg=
 forge.cadoles.com/Pyxis/golang-socketio v0.0.0-20180919100209-bb857ced6b95/go.mod h1:I6kYOFWNkFlNeQLI7ZqfTRz4NdPHZxX0Bzizmzgchs0=
-github.com/caarlos0/env v3.3.0+incompatible h1:jCfY0ilpzC2FFViyZyDKCxKybDESTwaR+ebh8zm6AOE=
+github.com/caarlos0/env v3.4.0+incompatible h1:FRwBdvENjLHZoUbFnULnFss9wKtcapdaM35DfxiTjeM=
-github.com/caarlos0/env v3.3.0+incompatible/go.mod h1:tdCsowwCzMLdkqRYDlHpZCp2UooDD3MspDBjZ2AD02Y=
+github.com/caarlos0/env v3.4.0+incompatible/go.mod h1:tdCsowwCzMLdkqRYDlHpZCp2UooDD3MspDBjZ2AD02Y=
+github.com/cenkalti/backoff v2.0.0+incompatible h1:5IIPUHhlnUZbcHQsQou5k1Tn58nJkeJL9U+ig5CHJbY=
+github.com/cenkalti/backoff v2.0.0+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-chi/chi v3.3.3+incompatible h1:KHkmBEMNkwKuK4FdQL7N2wOeB9jnIx7jR5wsuSBEFI8=
 github.com/go-chi/chi v3.3.3+incompatible/go.mod h1:eB3wogJHnLi3x/kFX2A+IbTBlXxmMeXJVKy9tTv1XzQ=
 github.com/gorilla/websocket v1.4.0 h1:WDFjx/TMzVgy9VdMMQi2K2Emtwi2QcUQsztZ/zLaH/Q=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
+github.com/grandcat/zeroconf v0.0.0-20180329153754-df75bb3ccae1 h1:VSELJSxQlpi1bz4ZwT+93hPpzNLRcgytLr77iVRJpcE=
+github.com/grandcat/zeroconf v0.0.0-20180329153754-df75bb3ccae1/go.mod h1:YjKB0WsLXlMkO9p+wGTCoPIDGRJH0mz7E526PxkQVxI=
 github.com/miekg/dns v1.0.12 h1:814rTNaw7Q7pGncpSEDT06YS8rdGmpUEnKgpQzctJsk=
 github.com/miekg/dns v1.0.12/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
-github.com/mitchellh/mapstructure v1.0.0 h1:vVpGvMXJPqSDh2VYHF7gsfQj8Ncx+Xw5Y1KHeTRY+7I=
+github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQzvN1EDeE=
-github.com/mitchellh/mapstructure v1.0.0/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
+github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
-github.com/oleksandr/bonjour v0.0.0-20160508152359-5dcf00d8b228 h1:Cvfd2dOlXIPTeEkOT/h8PyK4phBngOM4at9/jlgy7d4=
-github.com/oleksandr/bonjour v0.0.0-20160508152359-5dcf00d8b228/go.mod h1:MGuVJ1+5TX1SCoO2Sx0eAnjpdRytYla2uC1YIZfkC9c=
 github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=