add geo URL and status JSON

Signed-off-by: Colin Sullivan <colin@synadia.com>

examples/nats-echo/main.go

@@ -47,14 +47,24 @@ func printMsg(m *nats.Msg, i int) {
 	log.Printf("[#%d] Echoing from [%s] to [%s]: %q", i, m.Subject, m.Reply, m.Data)
 }
 
+func printStatusMsg(m *nats.Msg, i int) {
+	log.Printf("[#%d] Sending status from [%s] to [%s]: %q", i, m.Subject, m.Reply, m.Data)
+}
+
+type serviceStatus struct {
+	Id  string `json:"id"`
+	Geo string `json:"geo"`
+}
+
 func main() {
 	var urls = flag.String("s", nats.DefaultURL, "The nats server URLs (separated by comma)")
 	var userCreds = flag.String("creds", "", "User Credentials File")
 	var nkeyFile = flag.String("nkey", "", "NKey Seed File")
+	var serviceId = flag.String("id", "NATS Echo Service", "Identifier for this service")
 	var showTime = flag.Bool("t", false, "Display timestamps")
 	var showHelp = flag.Bool("h", false, "Show help message")
 	var geoloc = flag.Bool("geo", false, "Display geo location of echo service")
-	var geo string
+	var geo string = "unknown"
 
 	log.SetFlags(0)
 	flag.Usage = usage
@@ -74,7 +84,7 @@ func main() {
 		geo = lookupGeo()
 	}
 	// Connect Options.
-	opts := []nats.Option{nats.Name("NATS Echo Service")}
+	opts := []nats.Option{nats.Name(*serviceId)}
 	opts = setupConnOptions(opts)
 
 	if *userCreds != "" && *nkeyFile != "" {
@@ -101,37 +111,40 @@ func main() {
 		log.Fatal(err)
 	}
 
-	subj, i := args[0], 0
+	subj, iEcho, iStatus := args[0], 0, 0
+	statusSubj := subj + ".status"
 
-	handleMsg := func(msg *nats.Msg) {
-		i++
+	nc.QueueSubscribe(subj, "echo", func(msg *nats.Msg) {
+		iEcho++
+		printMsg(msg, iEcho)
 		if msg.Reply != "" {
-			printMsg(msg, i)
 			// Just echo back what they sent us.
-			if geo != "" {
-				m := fmt.Sprintf("[%s]: %q", geo, msg.Data)
-				nc.Publish(msg.Reply, []byte(m))
+			var payload []byte
+			if geo != "unknown" {
+				payload = []byte(fmt.Sprintf("[%s]: %q", geo, msg.Data))
 			} else {
-				nc.Publish(msg.Reply, msg.Data)
+				payload = msg.Data
 			}
+			nc.Publish(msg.Reply, payload)
 		}
-	}
-
-	nc.QueueSubscribe(subj, "echo", func(msg *nats.Msg) {
-		handleMsg(msg)
 	})
-	allSubj := subj + ".all"
-	nc.Subscribe(allSubj, func(msg *nats.Msg) {
-		handleMsg(msg)
+	nc.Subscribe(statusSubj, func(msg *nats.Msg) {
+		iStatus++
+		printStatusMsg(msg, iStatus)
+		if msg.Reply != "" {
+			payload, _ := json.Marshal(&serviceStatus{Id: *serviceId, Geo: geo})
+			nc.Publish(msg.Reply, payload)
+		}
 	})
 	nc.Flush()
 
 	if err := nc.LastError(); err != nil {
 		log.Fatal(err)
 	}
 
+	log.Printf("Echo Service ID: [%s]", *serviceId)
 	log.Printf("Echo Service listening on [%s]\n", subj)
-	log.Printf("Echo Service (All) listening on [%s]\n", allSubj)
+	log.Printf("Echo Service (Status) listening on [%s]\n", statusSubj)
 
 	// Now handle signal to terminate so we can drain on exit.
 	c := make(chan os.Signal, 1)
@@ -185,9 +198,15 @@ type geo struct {
 // lookup our current region and country..
 func lookupGeo() string {
 	c := &http.Client{Timeout: 2 * time.Second}
-	resp, err := c.Get("https://ipapi.co/json")
+
+	url := os.Getenv("ECHO_SVC_GEO_URL")
+	if len(url) == 0 {
+		url = "https://ipapi.co/json"
+	}
+
+	resp, err := c.Get(url)
 	if err != nil || resp == nil {
-		log.Fatalf("Could not retrive geo location data: %v", err)
+		log.Fatalf("Could not retrieve geo location data: %v", err)
 	}
 	defer resp.Body.Close()
 	body, _ := ioutil.ReadAll(resp.Body)