如何在GoLang中的CoAP中为服务器编写服务端点PUT请求方法？

I tried to write client and server for CoAP serivce in GoLang. I used https://github.com/dustin/go-coap for this.

I successfully able to call POST end point but not able to call PUT. Following are the questions I have

1. When I call POST endpoint, my Go client says time out. But server receives the request. How I can increase client timeout?

What I tried code: Client Code:

req := coap.Message{
    Type:      coap.Confirmable,
    Code:      coap.POST,
    MessageID: 12345,
    Payload: []byte(`Hello CoAP Server `),
}
path := "/App"
if len(os.Args) > 1 {
    path = os.Args[1]
}
req.SetOption(coap.ETag, "weetag")
req.SetPathString(path)

c, err := coap.Dial("udp", "localhost:5683")
rv, err := c.Send(req)  

2. How I can specify PUT service endpoint in Go? It looks like we dont specify request method type for CoAP/UDP. But, if say, I have a PUT endpoint app/{appId}. It doesnt accept {appID}. it works only if I change this to app/appID. But I want this appID as argument and not path.

Client Code:

    req := coap.Message{
    Type:      coap.Confirmable,
    Code:      coap.PUT,
    MessageID: 12345,
    Payload: []byte(`Hello CoAP Server `),
    }
    path := "/App/fb"   //here fb is app id and this can be anything
    if len(os.Args) > 1 {
    path = os.Args[1]
    }
    req.SetOption(coap.ETag, "weetag")
req.SetPathString(path)    
c, err := coap.Dial("udp", "localhost:5683")
rv, err := c.Send(req)  

Server Code for POST and PUT requests:

mux := coap.NewServeMux()
// TODO-later: use UDP/coap
mux.Handle("/App", coap.FuncHandler(Register))
mux.Handle("/App/{AppID}", coap.FuncHandler(UpdateApp))

err := coap.ListenAndServe("udp", ":5683", mux)

Here is server code for update application by PUT request. Here I dont know how I can specify endpoint as PUT in CoAP. Can someone suggest me how I can create this endpoint mux.Handle("/App/{AppID}", coap.FuncHandler(UpdateApp)) as PUT?

Or even let me know if there is better Go library for CoAP Go Services?

According to this example:

https://github.com/dustin/go-coap/blob/master/example/server/coap_server.go

looks like a go-coap handler is only bound by URI. I think you'll have to handle request of different types by yourself.

A request with an unrecognized or unsupported Method Code MUST generate a 4.05 (Method Not Allowed) piggybacked response.

From: CoAP RFC 7252 Section 5.8 Method definitions

Unfortunately I didn't learn go and never used go-coap so cannot show a snippet. Though I think it would be pretty easy: you just need to response back with NON-4.05 with the same MID and token.