It is a Sub/Pub server and client using CoAP protocol.
It will keep a heart beat signal from client to server if you subscription a topic to remain your UDP port channel.
go get github.com/kkdai/CoapPubsub
Create a 1024 buffer for pub/sub server and listen 5683 (default port for CoAP)
package main
import (
"log"
. "github.com/kkdai/CoapPubsub"
)
func main() {
log.Println("Server start....")
serv := NewCoapPubsubServer(1024)
serv.ListenAndServe(":5683")
}Create a client to read input flag to send add/remove subscription to server.
package main
import (
"flag"
"fmt"
"log"
. "github.com/kkdai/CoapPubsub"
)
func main() {
flag.Parse()
if len(flag.Args()) < 3 {
fmt.Println("Need more arg: cmd topic msg")
return
}
cmd := flag.Arg(0)
topic := flag.Arg(1)
msg := flag.Arg(2)
fmt.Println(cmd, topic, msg)
client := NewCoapPubsubClient("localhost:5683")
if client == nil {
log.Fatalln("Cannot connect to server, please check your setting.")
}
if cmd == "ADDSUB" {
ch, err := client.AddSub(topic)
log.Println(" ch:", ch, " err=", err)
log.Println("Got pub from topic:", topic, " pub:", <-ch)
}
log.Println("Done")
}ex: Add subscription on topic "t1"
client ADDSUB t1 msg
ex: Remove subscription on topic "t1"
client REMSUB t1 msg
ex: Publish "mmmmm" to subscription topic "t1"
client PUB t1 mmmmm
- Hadle for UDP packet lost condition
- Gracefully network access
TBD
It is one of my project 52.
This package is licensed under MIT license. See LICENSE for details.