Added pub/sub sub-commands for both subscriber and publisher client cli

cmd/msgbus/main.go

@@ -1,15 +1,20 @@
 package main
 
 import (
+	"bytes"
 	"flag"
 	"fmt"
 	"log"
+	"net/http"
+	"os"
 
 	"golang.org/x/net/websocket"
 
 	"github.com/prologic/msgbus"
 )
 
+const defaultTopic = "hello"
+
 var (
 	host string
 	port int
@@ -26,8 +31,56 @@ func init() {
 func main() {
 	flag.Parse()
 
+	if flag.Arg(0) == "sub" {
+		subscribe(flag.Arg(1))
+	} else if flag.Arg(0) == "pub" {
+		publish(flag.Arg(1), flag.Arg(2))
+	} else {
+		log.Fatalf("invalid command %s", flag.Arg(0))
+	}
+}
+
+func publish(topic string, message string) {
+	var payload bytes.Buffer
+
+	if topic == "" {
+		topic = defaultTopic
+	}
+
+	if message == "" || message == "-" {
+		log.Printf("Reading message from stdin...\n")
+		buf := make([]byte, 1024)
+		_, err := os.Stdin.Read(buf)
+		if err != nil {
+			log.Fatal(err)
+		}
+		payload.Write(buf)
+	} else {
+		payload.Write([]byte(message))
+	}
+
+	url := fmt.Sprintf("http://%s:%d/%s", host, port, topic)
+
+	client := &http.Client{}
+
+	req, err := http.NewRequest("PUT", url, &payload)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	_, err = client.Do(req)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func subscribe(topic string) {
+	if topic == "" {
+		topic = defaultTopic
+	}
+
 	origin := "http://localhost/"
-	url := fmt.Sprintf("ws://%s:%d/push/foo", host, port)
+	url := fmt.Sprintf("ws://%s:%d/push/%s", host, port, topic)
 	ws, err = websocket.Dial(url, "", origin)
 	if err != nil {
 		log.Fatal(err)