Avoid panic if printer is off or unreachable for some reason.

Closes #16
Closes #17
Closes #15

proxy/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"flag"
 	"ippserver/packages/ipp"
 	"ippserver/packages/mdnsserver"
 	"net/http"
@@ -10,6 +11,15 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+var (
+	loglevel string
+	location string
+)
+
+func init() {
+	flag.StringVar(&loglevel, "loglevel", "info", "The wanted loglevel error/info/debug")
+}
+
 func main() {
 	customFormatter := new(log.TextFormatter)
 	customFormatter.TimestampFormat = "2006-01-02 15:04:05"
@@ -39,29 +49,32 @@ func handle(w http.ResponseWriter, r *http.Request) {
 	mut.Unlock()
 	if r.Method != http.MethodPost {
 		http.Error(w, "Unsupported method", http.StatusMethodNotAllowed)
-
 	}
 
 	request := ipp.NewRequest(0, 0)
 	request.UnMarshal(r.Body)
-	log.Infof("Upstream Request: \n%v\n", request)
+	log.Infof("Upstream Request: id: %v op: %v", request.RequestID(), request.Operation())
 	var response *ipp.Response
+	var err error
 	switch request.Operation() {
 	case ipp.GetPrinterAttributes:
 		response = handleGetPrinterAttributes(request)
 	case ipp.PrintJob:
-		response = handlePrintJob(request, r.Body, requestID)
+		response, err = handlePrintJob(request, r.Body, requestID)
 	case ipp.GetJobs:
-		response = handleGetJobs(request, requestID)
+		response, err = handleGetJobs(request, requestID)
 	case ipp.ValidateJob:
 		response = handleValidateJob(request)
 	case ipp.GetJobAttributes:
-		response = handleGetJobAttributes(request, requestID)
+		response, err = handleGetJobAttributes(request, requestID)
 	default:
 		response = ipp.NewResponse(ipp.ClientErrorBadRequest, request.RequestID())
 	}
-
-	log.Infof("Upstream Response:\n%v\n", response)
+	if err != nil {
+		log.Errorf("Failed to handle request: %v", err.Error())
+		response = ipp.NewResponse(ipp.ServerErrorServiceUnavailable, request.RequestID())
+	}
+	log.Infof("Upstream Response: %v", response.Header())
 	data := response.Marshal()
 	w.Write(data)
 }